Colorado Hail, September 9–10, 2026: 3.47-Inch Radar Estimates Over Pueblo County

I've been roofing in Colorado for about three years, and every September I watch the same thing happen: homeowners file hail season away for the year around Labor Day, and the radar keeps going. September 9 and 10 put up two of the biggest single-day hail footprints Colorado has seen all season.

Then the honest part, which matters more than the size: if you live in Denver, Aurora, Fort Collins, Greeley, or Colorado Springs, this storm was not over your house. Not a single qualifying cell. I'd rather tell you that than let you go looking for damage that a radar says was never there.

Here's what the data shows, where it actually hit, and what I'd do about it if it was my address.

What the Radar Recorded, Day by Day

MRMS (Multi-Radar Multi-Sensor) is a NOAA system that stitches the national radar network into one grid and flags cells — each roughly one square kilometer — where it estimates hail is falling. It is a model estimate, not a physical measurement, but it is the most consistent address-level record we have of which neighborhoods sat under a storm.

The counts below are distinct grid cells estimated at 1 inch or larger, statewide. MRMS re-snapshots the same cell many times a day; each cell is counted once here, however often it was re-reported. The size column is the peak among each day's new cells — not the peak sitting in its 24-hour bucket, which can be yesterday's stone.

Two new hail days back to back, and the second one was the wider of the pair. For scale against the rest of the month: the entire Labor Day week that ran from August 31 through September 7 produced four hail days whose biggest statewide footprint was 561 cells. September 10 alone was nearly double that.

The size distribution is the part that would have had my phone ringing if it had happened 100 miles north. On September 9, 147 of those cells were estimated at 2 inches or larger and 17 at 3 inches or larger. On September 10: 216 cells at 2 inches or more, 25 at 3 inches or more.

Why September 11 Doesn't Count

MRMS publishes a trailing 24-hour maximum. A snapshot taken just after midnight re-reports the previous day's cells under the new date, so a date can show dozens of flagged cells and still be, strictly, the same hail that fell the day before.

That is exactly what September 11 is. All 43 of its qualifying cells had already been reported on September 10 — not one new cell. Colorado's counter on the Colorado hail statistics page excludes dates like that, and so does this post. If you see a roundup claiming Colorado had three straight hail days over this stretch, that's the trailing-maximum artifact being read as a third storm.

The same rule is why HailScore's own storm record for September 10 in Pueblo County sets 62 of that date's cells aside: they were the September 9 storm still inside the 24-hour window.

Where It Actually Hit

Both days were a Pueblo-and-southeastern-plains event, full stop.

And the negative, which is the useful half for most of the people reading this:

Pueblo is a Front Range county, so "the Front Range got hail" is technically true and completely useless. The corridor from Fort Collins through Colorado Springs recorded nothing at all on either day. The hail was in and south-east of Pueblo.

If you're in Pueblo, the Pueblo hail damage page has the longer history for the city, and your address-level record is the thing actually worth checking.

What 3.47 Inches Means, and What It Doesn't

At 3.47 inches you're past baseball and reaching toward softball. From the jobsite: around 1.5 inches, asphalt shingles typically start bruising — the granule matrix compresses and fractures, and it is not always visible from the ground. By 2 inches you get more consistent bruising, cracked tab corners, and accelerated granule loss. Past 3 inches, an older asphalt roof sitting under the core rarely comes through clean.

Two caveats I'd want stated if this were my roof.

First, 3.47 inches was the single strongest cell in the state, not what fell on any particular street. A storm's core is a small part of its footprint, and this one's core was over Pueblo County.

Second, MESH is tuned so that roughly 75% of measured hail comes in at or below the radar estimate; read a size as a class (within about one tier), not as a caliper reading. There's a fuller explainer of what MESH is and isn't on our MESH reference page — it's the page I'd point a reporter at before they write "3.47-inch hail fell on Elm Street," because that's not what a grid estimate says.

And the line that stays true on every one of these posts: HailScore™ measures hail exposure recorded in NOAA data. It does not confirm damage. Two houses on the same block can come out of one storm completely differently, depending on which side of the swath edge they sat on and what shape their shingles were in going into it. Only someone physically on your roof can tell you what yours looks like.

What to Do Now

1. Check the record for your address, not the headline for your state. A statewide roundup cannot tell you whether a storm tracked over your street. Our free hail check by address pulls the documented storm history for a specific property — dates, estimated sizes, distances — from 40.4M+ NOAA-linked hail records across all sources, including 8.8M+ NOAA NEXRAD radar records going back to 2015. No signup for the basic report.

2. Walk the cheap evidence first. Gutters, downspouts, window screens, and aluminum vent fins dent at lower hail sizes than roofing does and are visible from the driveway. Fresh dents on soft metal mean something hit hard enough to be worth a closer look. No dents at all is real information too.

3. Know your roof's age before you call anyone. A 15-year-old asphalt shingle and a 3-year-old one respond very differently to identical hail. If you don't have records, your county assessor's permit history is a reasonable starting point.

4. Be specific with a door knock. If someone shows up in the Denver metro this month citing "the September storm," ask which date and which county. On September 9 and 10, the radar recorded nothing of an inch or more anywhere in the metro. In Pueblo, the storm was real — and the honest version of that conversation still ends with an inspection, not a signature.

5. Get documentation before you file anything. Dated photos of the roof surface, gutters, and any vehicle damage give you a baseline that predates the first contractor or adjuster conversation. A good roofer will tell you plainly whether what they're seeing is storm-related or ordinary wear.

Hail season in Colorado officially runs April through September, and this stretch is a reminder that the back half of September still counts. But the useful version of that sentence is address-level, not statewide — and for most of the Front Range, September 9–10 was a storm that happened somewhere else.

For the storm week just before this one, see our Labor Day week Colorado hail recap, which tracked a 3.94-inch peak on the southeastern plains under the same pattern.

Look up your property's full hail exposure history, free, at HailScore. HailScore documents radar-recorded hail exposure near an address. It does not confirm roof damage — only a licensed inspector can do that.