Short answer: Colorado's Front Range hail season peaks hard in June and effectively ends after August. In NOAA's Storm Events Database, the six counties we serve recorded 1,412 hail events from 2000 to 2025 — 38% of them in June alone and just 2.5% across September and October combined. November through March: zero, in 26 years. Hail damage does not follow that calendar, though. Bruising from a June storm stays invisible from the ground until it leaks, which is why fall is the right time to look.
If you live along the Front Range you have a rough sense of when hail happens. Here is the precise version, from the National Oceanic and Atmospheric Administration's Storm Events Database rather than from memory.
We publish this data already — every recorded hail event for the six counties we serve lives on our Storm Almanac, and each town page carries its own county's record. This post is the calendar view of the same numbers: which months actually produce hail here, how sharply the season ends, and what that means for a homeowner in September.
When is hail season in Colorado?
Between 2000 and 2025, NOAA recorded 1,412 hail events across Douglas, Arapahoe, Elbert, Jefferson, Adams and Denver counties. Here is how they fall by month:
- January – March — 0 events, 0%
- April — 72 events, 5.1%
- May — 263 events, 18.6%
- June — 537 events, 38.0%
- July — 272 events, 19.3%
- August — 232 events, 16.4%
- September — 32 events, 2.3%
- October — 4 events, 0.3%
- November – December — 0 events, 0%
Two things stand out. The first is how concentrated it is: June alone is 38% of the entire 26-year record, and May through July together are 76%. The second is how abrupt the ends are. There is not a single recorded hail event in these six counties in November, December, January, February or March — not one, in 26 years.
When does hail season end on the Front Range?
Practically speaking, at the end of August.
August is still a real month — 232 events, 16% of the record. September drops to 32 events, 2.3%. October has four. That is a roughly seven-fold drop from August to September, and another eight-fold drop from September to October.
But "rare" is not "never," and the honest version matters here because you will read "hail season ends in September" on a dozen roofing sites without a number attached to it. The record contains a 2.00-inch stone in Elbert County on September 12, 2002 and a 1.75-inch stone in Elbert County on October 6, 2015 — golf-ball size, in October. And the latest calendar-date event anywhere in the six-county record is October 27, 2025, in Douglas County. That was last year.
One more genuinely odd detail from the record: September 29 appears twice, in consecutive years. NOAA logged hail across Arapahoe, Douglas and Elbert counties on September 29, 2014, and again across Jefferson, Denver, Douglas and Arapahoe counties on September 29, 2015. Late-September hail on the Front Range is unusual. Two years running on the same date is a coincidence, but it is a documented one.
Does hail season look the same in every county?
No, and the differences are bigger than you would expect for counties that border each other.
- Elbert County — 330 events (2000–2025); peak month June (114); 7 in September, 1 in October
- Arapahoe County — 287 events (2000–2025); peak month June (127); 8 in September, 1 in October
- Douglas County — 242 events (2000–2025); peak month June (103); 7 in September, 2 in October
- Jefferson County — 212 events (2000–2025); peak month June (68); 9 in September, 0 in October
- Adams County — 211 events (2000–2025); peak month June (83); 0 in September, 0 in October
- Denver County — 130 events (2000–2025); peak month May (49); 1 in September, 0 in October
Denver County is the only one of the six where May outranks June — 49 events to 42. Every other county peaks in June, most of them decisively.
Elbert and Jefferson are the only two counties where August outranks July — Elbert 78 events to 67, Jefferson 46 to 40. Elbert sits east and south, out over the plains behind the Palmer Divide; Jefferson runs up against the foothills on the other side of the metro. Both have seasons that carry later and harder into late summer than the counties between them do. If you are in Elizabeth, Kiowa or Lakewood, your August is not the metro's August.
And Adams County has zero September or October events in 26 years — the only county in the set with a completely clean fall.
Why does the Front Range get so much hail in June?
The short version is geography stacked on top of altitude. Storms build over the foothills in the afternoon and track east across the metro. The freezing level here sits low enough that stones survive the fall to the ground instead of melting on the way down, which is why a storm that would drop rain in Kansas drops ice here. June combines the strongest afternoon instability with a freezing level that is still low, and the Palmer Divide — the ridge running east from the mountains between Denver and Colorado Springs — adds a lift mechanism that fires storms in roughly the same place over and over.
That is also why hail here is so patchy. Two houses on the same street can get completely different outcomes, which is the single most important thing to understand about a county-level hail record: a recorded event near your town is not evidence that a stone hit your roof, and no record is not evidence that one didn't. We say that on every page that carries this data.
The season is ending — so what should I actually do in the fall?
This is where the calendar and the damage stop lining up.
The storms mostly stop after August. The damage from June, July and August does not. Hail bruising is a break in the mat under the granules; it does not leak on day one and it does not look like anything from the driveway. What it does is fail later, and on the Front Range "later" means after the first hard freeze-thaw cycle, which is usually a matter of weeks from now.
So fall is the calm window — the one stretch where you can look at this on your own schedule rather than in a February leak or in a driveway conversation with someone who knocked.
- Do the free two-minute check yourself, from the ground. Gutters, downspouts, metal roof vents, the fins on your AC condenser. Soft metal dents at a smaller stone size than asphalt bruises at. If your gutters are clean, your roof most likely is too. That is the single highest-value thing a homeowner can do without a ladder, and it costs nothing.
- Write down the storm date if you think one hit you. Not "sometime in August." If you can't recall, our county hail history will narrow it down — that is most of why we publish it.
- Clear the gutters before the first freeze. Unrelated to hail, and the cheapest roof-adjacent maintenance there is. Ice dams start with a blocked gutter.
- If you want it confirmed, get someone on the roof, not in the driveway. Bruising is a texture you find with your hand as often as your eye. Drone photos and ground-level looks miss it routinely.
- Get the findings in writing either way — including "your roof is fine."
Is it too late to file a claim for a summer storm?
Probably not, but the deadline is not the one most sites quote. Telling your insurer about a loss is governed by your policy, not by any Colorado statute — most policies ask for notice "promptly" or "as soon as practicable," and only your declarations page says what yours requires. Suing your insurer is what the statutes cover, and the two-year figure you will read everywhere is the tort limitation; a dispute over your own policy is a contract action. We wrote that up with the citations here.
The practical risk of waiting isn't legal, it's evidentiary: the further you get from a storm date, the harder it is to tie damage to it. Which is another argument for looking in the fall rather than in the spring.
Hail counts on this page come from the NOAA NCEI Storm Events Database (public domain), event type hail, 2000–2025, for Douglas, Arapahoe, Elbert, Jefferson, Adams and Denver counties. NOAA's reporting has grown more thorough over time, so early years in any county are likely undercounts — we state that on the Storm Almanac too. County-level records describe counties, not individual roofs.
Last updated September 7, 2026.