California context 2026: The Inland Empire and Riverside County received measurable hail in the spring storms of 2023 and 2025. While hailstones over one inch are rare in Southern California, smaller hail combined with high winds and debris is enough to cause microcracks in solar cells. Homeowners who ignored post-storm monitoring saw 8 to 12% production losses within six months that were traced back to storm-induced cell damage.
1. How Often Hail Hits California
Southern California is not the Midwest, but hail does happen here. The Inland Empire, including Riverside County, Temecula, Murrieta, Menifee, and the surrounding foothills, sees the highest hail frequency in the region. The trigger is typically a cold upper-level trough dropping over the desert Southwest between February and April. Surface heating creates convection, and with enough instability you get hail-producing thunderstorms.
The National Oceanic and Atmospheric Administration (NOAA) Storm Events Database recorded hail events in Riverside County in 2019, 2021, 2022, 2023, and 2025. Most of those events involved hail between 0.25 and 0.75 inches. One event in April 2023 produced hail near 1 inch in portions of the San Jacinto Valley.
The upshot: California homeowners should not assume their panels will never encounter hail. The probability in any given year is low but not zero, and cumulative exposure over a 25-year system life is a real consideration.
2. The IEC 61215 Hail Test Standard
The international benchmark for solar panel hail resistance is IEC 61215, published by the International Electrotechnical Commission. This is the same standard used to certify that a panel meets minimum quality requirements for long-term outdoor performance.
The hail test within IEC 61215 works like this: a 25mm (approximately 1-inch) ice sphere is fired at the panel surface at 23 meters per second, which is about 51 miles per hour. The test fires the sphere at 11 specific points across the panel, targeting the most mechanically stressed locations including corners, edges, and the center of each cell zone.
To pass the test, a panel must show:
- ✓No visible cracking, chipping, or shattering of the glass or encapsulant
- ✓No open circuit or ground fault after impact
- ✓Power output degradation of no more than 5% compared to pre-test baseline
- ✓No failure of the insulation test (isolation resistance must remain above threshold)
Key limitation: IEC 61215 tests one specific hailstone size. It does not simulate hail larger than 25mm, hail arriving at steeper angles, repeated impacts at the same location, or ice with density differences from natural hail. Real-world hail events can exceed these parameters, which is why the test is a minimum standard, not a guarantee.
3. UL 1703 Testing
In the United States, Underwriters Laboratories (UL) published UL 1703 as the domestic flat-plate photovoltaic module standard. Its hail test is functionally similar to the IEC 61215 hail module: 25mm ice balls at 23 m/s, fired at 11 impact points.
UL 1703 has largely been superseded by UL 61730, which aligns more closely with IEC 61215 and is now the primary U.S. certification path for panels installed after 2021. If you are reviewing panel specifications, you may see either standard cited depending on when the module was certified.
Both UL 1703 and UL 61730 require passing the hail test before a panel can receive UL listing. All major panel brands sold through reputable U.S. installers carry one of these certifications. If a panel does not list either UL 61730 or IEC 61215 certification on the spec sheet, that is a serious red flag.
4. What Hail Ratings Mean in Practice
Passing IEC 61215 or UL 61730 tells you the panel survived a standardized lab test. Here is what that translates to in a real California hail event:
Very low risk of structural damage. Minor surface pitting is possible on older panels where anti-reflective coating has degraded. Production impact is typically negligible.
Panels that pass IEC 61215 should survive without visible cracking. However, microcracking inside cells is possible, particularly on panels older than 10 years or panels with pre-existing stress fractures from thermal cycling.
The IEC test does not cover this size. Visible glass cracking and cell damage become likely. Replacement is probable. This size is associated with severe thunderstorm warnings and is uncommon but not impossible in the IE.
One nuance that matters: panel angle affects impact force. A panel tilted at 15 to 20 degrees (typical for Southern California rooftop systems) receives hail at a glancing angle rather than head-on. This reduces the effective impact energy compared to the laboratory test, which fires at a perpendicular angle. In practice, this means real-world hail at the test size is often less damaging than the lab suggests.
5. How Hail Damages Solar Panels
Solar panels are built with tempered glass on the front, an encapsulant layer (usually EVA or polyolefin), silicon cells, a back sheet, and a frame. Hail can damage any of these layers, but not always in ways you can see from the ground.
Visible spider-web fractures in the tempered glass cover. Water can enter through cracks and accelerate degradation of the encapsulant and cells. This is the most obvious form of hail damage.
Small craters or chips in the glass surface without full cracks. These reduce light transmission slightly and create stress concentration points that can grow into larger cracks over subsequent thermal cycles.
Separation of the encapsulant from the glass or back sheet, often visible as milky or bubbled areas under the glass. Can occur immediately or develop over months after an impact event.
Dark lines or discolored areas in the solar cells visible through the glass, usually only if the glass itself has cracked or if damage is severe. Individual cracked cells create current mismatch losses across the string.
Dents or bends in the aluminum frame can compromise the structural integrity of the module, affect mounting hardware, and over time allow water infiltration at the frame-glass junction.
The most common and most dangerous damage type. Cracks inside silicon cells that are invisible to the eye but degrade performance over time. Covered in detail in the next section.
6. Hidden Microcracks: The Silent Problem
Microcracks are fractures inside the silicon cell material that are not visible without electroluminescence (EL) imaging equipment. A hailstone does not need to crack the glass to create them. The pressure wave from impact, especially combined with a panel already stressed from years of thermal expansion and contraction, can fracture cell material internally while leaving the glass intact.
Why this matters: a microcracked cell starts out producing close to its rated output. Over time, especially through subsequent thermal cycling (summer heat followed by cool nights), the cracks propagate. Inactive cell regions (called "dead zones") grow. Current pathways change, creating hot spots that further accelerate degradation.
Homeowners who had hail events in spring 2023 and did not inspect their systems frequently reported production losses of 8 to 15% by the end of the year that their monitoring apps attributed to seasonal variation or inverter behavior. In many of those cases, EL imaging revealed extensive microcracking that originated at the storm date visible in the production logs.
Why this matters for insurance: Your production drop data with a timestamp linked to a documented hail event is evidence. Without monitoring data, proving microcrack damage to an adjuster is difficult. The section on monitoring data below explains how to use your system logs as documentation.
7. How to Inspect Your Panels After a Hail Storm
After a hail event, run through this inspection sequence before calling a contractor or filing a claim. The goal is to document as much as possible.
From the ground, use binoculars to scan each panel row. Look for white or silver star-burst cracks in the glass, dark spots or discolored areas in the cell pattern, milky or bubbled zones under the glass, and dents or bent sections in the frame. Take photos with your phone zoomed in. Do this within 24 hours of the storm while the evidence is fresh.
Before assuming your panels were hit, look at what else hail struck: your roof shingles, gutters, downspouts, any skylights, and vehicles in the driveway. Hail damage on these surfaces correlates with damage to panels. Insurance adjusters look for this cross-evidence to confirm a legitimate hail event rather than pre-existing damage.
Wet rooftops after a storm are a fall hazard. Cracked panels after a hail event may carry live voltage even if visibly broken. Contact a licensed solar contractor or a Certified Thermographic Inspector trained for solar work. Do not attempt a hands-on panel inspection yourself.
Log into your monitoring app (Enphase Enlighten, SolarEdge, Fronius Solar.web, or similar) and screenshot the production graph for the storm day and the two days following. A production drop on a sunny day after the storm is the clearest evidence of damage. Save these screenshots in the same folder as your visual inspection photos.
Note the date and time of the hail event using a local weather service or NOAA storm reports. This documented weather event is what ties your production drop and physical damage to a specific insured peril. The NOAA Storm Events Database at ncdc.noaa.gov provides county-level storm records searchable by date.
8. Using Monitoring Data as Evidence of Damage
Your solar monitoring system is your most powerful tool after a hail event, and most homeowners do not know this. The monitoring platform records production data at 5 to 15 minute intervals, every day. This creates a timestamped log that can show exactly when production behavior changed.
What you are looking for: compare a clear sunny day in the week before the storm to a clear sunny day in the week after. If production dropped more than 5 to 8% with no shading, soiling, or inverter issues to explain it, you have evidence of potential storm damage.
Microinverter systems (Enphase) give you panel-level data, which is even more useful. You can identify which specific panels dropped output and correlate that with which panels you saw surface damage on from the ground. This panel-level evidence is significantly stronger for insurance claims than system-level totals alone.
What to export from your monitoring system:
- -Daily production totals for 30 days before and after the event
- -Hourly production for the storm day and 3 days following
- -Panel-level data if you have microinverters or power optimizers
- -Any fault codes or alerts the system generated during or after the storm
- -System lifetime production curve showing the step-change at storm date
For more on setting up effective monitoring before a storm event, see our guide to solar monitoring systems in California.
9. Manufacturer Warranty vs. Homeowner Insurance: Which Covers Hail?
This is the most common point of confusion after a hail event. Homeowners contact their panel manufacturer expecting a warranty replacement, and the manufacturer declines the claim. Here is why, and what the correct path is.
- xDoes NOT cover physical damage from hail, wind, falling objects, or any external impact
- xCovers defects in materials and workmanship present at time of manufacture
- xCovers gradual performance degradation below the warranted threshold (typically 80-85% at year 25)
- xDoes NOT cover damage from acts of nature regardless of how well the panel passed IEC testing
- ✓Covers storm damage (hail, wind, hail-driven debris) under the dwelling coverage section
- ✓Panels are typically treated as permanently attached structures, like a skylight or chimney
- ✓Subject to your deductible, coverage limits, and whether solar is explicitly listed
- ✓Leased panels may be covered under the leasing company policy instead
One exception worth noting: some manufacturers offer an extended product warranty that explicitly covers hail impact up to a certain size. LG Solar (before exiting the solar market) offered this on some module lines. SunPower's comprehensive warranty historically included some weather damage coverage. Always read your specific warranty document, not just the marketing summary.
For a full breakdown of what solar warranties cover, see our guide to solar warranties explained for California homeowners.
10. What Your Homeowner Policy Actually Covers
Confirming solar panel coverage in your homeowner policy requires more than asking your agent a yes-or-no question. Here is what to verify specifically:
Solar panels on a roof are typically covered under Coverage A (Dwelling). Confirm your panels are not excluded or limited under a separate personal property section with a lower sublimit.
A 10 kW system in California replaced at 2026 prices costs roughly $25,000 to $35,000 including installation. If your Coverage A limit is below this threshold and your panels are damaged alongside the roof, you may not receive full replacement cost.
Replacement cost (RCV) policies pay what it costs to replace the panels with equivalent new panels. Actual cash value (ACV) policies deduct depreciation. A 10-year-old system under ACV might receive 40 to 60 cents on the dollar. Verify which you have.
If you lease your panels, you generally do not own them and cannot file a claim for them under your homeowner policy. The leasing company carries their own insurance on the equipment. Contact your leasing company (Sunrun, SunPower, Sunlease, etc.) immediately after damage to understand their claim process.
Your standard deductible applies. Some California policies have a separate windstorm or hail deductible that can be 1 to 2% of the insured dwelling value. On a $700,000 home, a 1% hail deductible is $7,000, which may exceed the cost of replacing one or two panels.
For California homeowners considering how insurance factors into the total cost of solar ownership, see our article on filing a solar panel insurance claim in California.
11. What to Tell Your Insurance Adjuster
Insurance adjusters who inspect residential rooftops after hail events are experienced with shingles, gutters, and skylights. Solar panels are less common in their day-to-day workflow. The information you give them upfront makes a significant difference in how the claim is handled.
Tell your adjuster these specific things:
Tell them the panel brand, model, wattage, quantity, and installation date. This is on your installer permit and your interconnection agreement. Having this ready speeds the replacement quote process.
Share your pre- and post-storm production screenshots showing the drop. Frame it as: 'My monitoring data shows production dropped X% on [date], which is the same date as the NOAA-documented hail event for Riverside County.'
Tell the adjuster: 'Beyond visible glass damage, hail can cause microcracking inside cells that is not visible to the eye but causes cumulative production loss. The standard inspection for this is electroluminescence imaging, which I would like included in the assessment.'
Many general adjusters do not carry EL imaging equipment or training. You can request that the claim include a licensed solar inspection with EL or IV curve testing in addition to the standard visual assessment. Some policies allow you to get an independent inspection paid for from the claim.
Confirm with the adjuster whether the settlement will be based on current panel replacement cost (equivalent wattage at current prices) or the original purchase price. Because panel costs have declined, an older system may be replaceable with higher-efficiency panels at the same or lower cost.
12. Cost to Replace One vs. Multiple Damaged Panels
Panel replacement cost in California in 2026 breaks down as follows:
| Scenario | Panel Cost | Total Est. Cost |
|---|---|---|
| Single panel replacement | $250 - $600 | $400 - $900 |
| 2 to 4 panels (same roof section) | $500 - $2,400 | $800 - $3,200 |
| 5 to 10 panels | $1,250 - $6,000 | $2,200 - $8,000 |
| Full system replacement (20 panels) | $5,000 - $12,000 | $18,000 - $30,000 |
Total cost includes panel cost plus labor, permitting (many California jurisdictions require a permit for panel replacements), and electrical inspection. String inverter systems may also require module-level power electronics if the original microinverter or optimizer attached to the damaged panel needs replacement.
An important consideration for older systems: if your panels are 10 or more years old and a hail event damages several of them, replacing only the damaged units can create a mismatch problem. Older panels with degraded output connected to new higher-wattage panels in the same string can reduce the performance of the new panels. A full system replacement may produce better long-term results, particularly if your insurance settlement covers the full array replacement cost.
Panel prices have dropped substantially since 2020. A 400W panel that cost $280 in 2020 costs closer to $180 to $220 in 2026 at the component level. This means your insurance replacement at "equivalent wattage today" may actually deliver a higher-performing system than you originally had.
13. Finding a Solar Inspector After a Hail Event in California
Not all solar contractors perform storm damage inspections, and not all inspection services carry the equipment needed for microcrack detection. Here is how to find the right resource after a hail event:
Your installing contractor has your system documentation and knows your roof configuration. Many will perform a post-storm inspection at no charge for their own installations, particularly if they have a workmanship warranty still in effect. Even if damage is physical (not workmanship-related), they are the fastest source for a damage assessment.
The North American Board of Certified Energy Practitioners (NABCEP) certifies solar installation and inspection professionals. A NABCEP-certified inspector has the training to assess both visible and performance-based damage. Use the NABCEP directory at nabcep.org to find certified professionals in Riverside County.
Electroluminescence (EL) imaging uses a camera sensitive to infrared emissions from solar cells to map microcracking patterns invisible to the eye. IV curve tracing measures the current-voltage relationship of each string or panel to identify underperforming units. Ask any inspector you hire whether they carry this equipment. Visual inspection alone is insufficient for microcrack documentation.
Ask the inspector to provide a written report that includes the inspection date, storm date reference, specific panels inspected, observed damage types, production impact estimate, and replacement recommendations. A written inspector report with NABCEP credentials is significantly more credible to an insurance adjuster than photos alone.
14. Are Any Solar Panels More Hail Resistant Than Others?
Within the standard IEC 61215 certification tier, all panels are tested to the same 25mm at 23 m/s benchmark. However, there are differences in construction that affect real-world hail resistance beyond the minimum test:
Standard panels use 3.2mm tempered glass. Some manufacturers offer 4mm or 5mm glass as an option, which provides meaningfully better impact resistance. Ask about glass thickness when comparing quotes.
Lightly textured (anti-reflective) glass distributes impact energy more evenly than smooth glass. Most modern panels use this by default, but it is worth confirming.
Half-cut cell panels (where each standard cell is cut in half) are inherently more resilient to partial shading and microcracking because a crack in one cell affects only half the current pathway rather than the full cell.
Glass-glass bifacial panels with no aluminum frame use tempered glass on both front and back, which some manufacturers claim improves mechanical strength. However, the frameless design also removes the structural support the frame provides against flexing loads.
Some manufacturers market panels as "Class 3" or "Class 4" hail rated. These ratings come from FM Approvals (Factory Mutual), a testing organization used primarily in the commercial and insurance industry. An FM Class 4 panel is tested with a 2-inch steel ball (simulating large hail) rather than the IEC standard 1-inch ice ball. FM Class 4 panels are meaningfully more hail-resistant but also more expensive. For most California homeowners, FM Class 4 is not necessary given the typical hail sizes in the region.
15. What You Can (and Cannot) Do to Prevent Hail Damage
The honest answer is that there is not much a homeowner can do to prevent hail damage in the moment. Panels are exposed equipment. But there are things that affect your long-term risk profile.
If you are still in the purchase phase, request 4mm or 5mm glass panels. The cost premium is modest relative to system total.
A working, active monitoring system is your documentation system. Gaps in monitoring data weaken an insurance claim. Check your system quarterly to confirm it is logging correctly.
Review your homeowner policy each time you make a significant home improvement, including solar. Confirm the dwelling coverage limit was updated to reflect the added system value.
Unlike some commercial installations in extremely hail-prone areas, residential rooftop panels in California do not typically have protective cover options. Remote tilt adjustment systems exist but cost more than the risk in a California context.
Not a realistic option. Residential rooftop panels are bolted to the roof structure and require a contractor to remove safely. By the time a hail storm is forecast, there is no time for this.
Questions About Your Solar System After a Storm?
If you had a hail event and are not sure whether your panels were damaged, the fastest answer comes from a production data review. Call us and we will walk through your monitoring data with you at no charge.
(951) 290-301416. FAQ: Solar Panels and Hail in California
Are solar panels hail proof?+
No panel is hail proof. Panels are hail resistant within the parameters of the IEC 61215 standard: 25mm hailstones at 23 m/s. Hail larger than 1 inch at high velocity can crack panels. The term hail proof is a marketing claim, not an engineering standard.
What is the IEC 61215 hail test standard and does it matter?+
IEC 61215 is the international certification standard for solar modules. The hail test fires 25mm ice spheres at 23 m/s across 11 panel impact points. A panel must show no visible cracking, no insulation failure, and no more than 5% power loss to pass. It is the minimum bar, not a guarantee against all hail scenarios.
Does hail in California actually damage solar panels?+
Most California hail events produce stones under 0.75 inches, which typically does not cause visible glass damage to modern panels. However, smaller hail combined with wind, repeated impacts, or panels with pre-existing stress can cause microcracking invisible to the eye. The Inland Empire and Riverside County have the highest hail frequency in Southern California.
How do I know if my solar panels were damaged by hail?+
Start with a ground-level visual inspection using binoculars. Then check your monitoring app for a production drop on clear days after the storm compared to clear days before. A drop of more than 5 to 8% without another explanation warrants a professional inspection including EL imaging.
Will my solar warranty cover hail damage?+
No. Manufacturer warranties cover defects in materials and workmanship, not physical damage from external events. Hail damage is an insurance claim, not a warranty claim. Contact your homeowner's insurance, not the panel manufacturer, after a storm event.
What is microcracking and why does it matter?+
Microcracks are fractures inside silicon solar cells that are not visible to the eye. They form from impact stress and propagate with subsequent thermal cycling. Over months and years they expand inactive zones in the cell, reducing current flow and causing output loss that can reach 10 to 15% or more in severely affected panels.
How much does it cost to replace a hail-damaged solar panel in California?+
A single panel replacement costs $400 to $900 including labor and permitting in California. Four to ten panels run $2,200 to $8,000. A full 20-panel system replacement is $18,000 to $30,000 installed. Insurance typically covers replacement cost minus your deductible.
Should I call my installer or my insurance company first after hail?+
Document everything first: photos, weather records, monitoring data screenshots. Then call your insurance company to open a claim. Contact your installer afterward to schedule a professional inspection. Having a solar-specific inspection report before the adjuster visits strengthens your claim.
Related Articles
Step-by-step process, documentation checklist, and what adjusters look for.
Product, performance, and workmanship warranties decoded.
How to use production data to catch problems early.
This article was written by the Temecula Solar Savings team for Southern California homeowners. Information on hail test standards references IEC 61215 Edition 2 and UL 61730 as of 2026. Insurance coverage specifics vary by policy and insurer. Consult your insurance provider and a licensed solar contractor for advice specific to your installation. Prices shown are estimates for California in 2026 and will vary.