Hail alley, by the numbers — every figure from a primary source
Last reviewed: July 20, 2026
Every roofer’s pitch in Colorado opens with a hail statistic, usually
unsourced and usually inflated. Here are the numbers that actually hold
up — each linked to the agency or document it comes from, with the date
we checked. Where a number couldn’t be verified at the source, it isn’t
on this page.
Colorado’s place in hail alley
The most hail-prone region in the country. NOAA’s National Severe
Storms Laboratory: “Nebraska, Colorado, and Wyoming usually have the
most hailstorms. The area where these three states meet – ‘hail alley’
– averages seven to nine hail days per year.” (NOAA NSSL, Severe Weather 101 — verified July 20,
2026)
244 major hail events in 2025. Colorado ranked sixth among U.S.
states for major hail events — hailstones one inch in diameter or
larger — per NOAA Storm Prediction Center data compiled by the
Insurance Information Institute. Texas led with 902; nationally there
were 5,432 hail events in 2025, up from 5,373 in 2024. (III, Facts + Statistics: Hail — verified July 20,
2026)
Colorado hail runs from pea to softball. The National Weather
Service in Pueblo: hailstones here vary “from pea size, around 3/8 of
an inch in diameter, to softball size, around 4 1/2 inches in
diameter.” (NWS Pueblo, Severe Weather Awareness — verified
July 20, 2026)
2025 major hail events — Colorado vs. the leaders
Hailstones one inch or larger logged in 2025: the three leading states and Colorado, which ranked sixth. Ranks 4–5 omitted — our source lists the leaders and Colorado. Source: NOAA Storm Prediction Center counts compiled by the Insurance Information Institute, verified July 20, 2026.
Colorado hail, to scale
Drawn to true relative scale. Size range as described by the National Weather Service in Pueblo; the one-inch severe threshold is NOAA's counting line; baseball-size hail was reported in the May 8, 2017 Denver storm (NWS Boulder).
The storm that explains your premium
On May 8, 2017, a supercell dropped hail up to baseball size across
the west Denver metro — Golden, Lakewood, Wheat Ridge, northwest Denver.
The National Weather Service’s storm summary records:
Insured damage of around $2.3 billion (a Rocky Mountain Insurance
Information Association figure), making it “Colorado’s most
expensive insured catastrophe.”
At the time, the second-costliest hailstorm in U.S. history.
A swath of golfball-and-larger hail nine miles wide, which is why
the damage total got so extreme — that’s not a neighborhood, it’s a
corridor of roofs.
For scale on what hail costs insurers nationally: State Farm alone
reported paying over $3.5 billion in hail claims in 2022, up more
than $1 billion from 2021. (III, citing State Farm’s March 2023 analysis)
What the state concluded from these numbers
Colorado’s legislature wrote its reading of the situation directly into
the 2026 roof-grant law’s legislative declaration (SB26-155,
§10-4-2001):
Extreme weather events including hail are “increasing in recent
years”;
Property owners face rising premiums “undermining the ability to
purchase, sell, and own a home”;
Data from North Carolina and Alabama shows that helping homeowners
strengthen roofs results in fewer claims — the model the Strengthen
Colorado Homes program is built on.
Our codes-by-city survey, mapped — county-level status as of July 20, 2026. Incorporated cities inside a county permit separately and can differ (Aurora and Centennial are surveyed separately in the table; Denver is its own city-and-county). Every status traces to a linked primary source in the full survey table. County boundaries: U.S. Census Bureau.
A note on numbers you won’t find here
Widely repeated figures like “Colorado’s annual hail damage” totals or
“average roof claim” amounts circulate without a checkable source, so we
don’t publish them. The largest U.S. hailstone on record, for the
curious, fell in Vivian, South Dakota in 2010 — eight inches across,
per NOAA. Colorado’s roofs deal with smaller stones arriving much more
often, which is the worse deal.
Questions people actually ask
How often does it hail in Colorado?
NOAA's National Severe Storms Laboratory puts Nebraska, Colorado, and Wyoming as the states with the most hailstorms, and the "hail alley" region where the three meet averages seven to nine hail days per year. In 2025, NOAA's Storm Prediction Center logged 244 major hail events in Colorado — hailstones an inch or larger — ranking the state sixth in the country.
What was Colorado's most damaging hailstorm?
The May 8, 2017 storm that crossed the west Denver metro — Golden, Lakewood, Wheat Ridge, northwest Denver — caused roughly $2.3 billion in insured damage, which the National Weather Service calls Colorado's most expensive insured catastrophe. The swath of golfball-and-larger hail was nine miles wide.
Is hail why Colorado homeowners insurance is so expensive?
Hail is a central driver. Colorado's own legislature, in the 2026 roof-grant law, found that extreme weather events including hail are increasing and that rising premiums are "undermining the ability to purchase, sell, and own a home" — which is the stated reason the Strengthen Colorado Homes grant program exists.