Boulder County, Colorado: hail history 2014–2026
Boulder County ranks #6 of 29 Colorado counties for hail: 197.3 reports per 1,000 square miles, 146 reports in all. Hail reached 1 inch on 30 days and 1.75 inches on 4. Record: 3 inches (a teacup), June 18, 2018 near Superior.
- 146reports
- 30days, 1 in+
- 4days, 1.75 in+
- 3 inlargest stone
Hail since my roof went on: Boulder County
Year by year
| Year | Reports | Days 1 in+ | Days 1.75 in+ | Largest |
|---|---|---|---|---|
| 2014 | 5 | 2 | 0 | 1.5 in |
| 2015 | 10 | 3 | 1 | 2.5 in |
| 2016 | 1 | 1 | 0 | 1 in |
| 2017 | 2 | 0 | 0 | 0.88 in |
| 2018 | 45 | 7 | 1 | 3 in |
| 2019 | 42 | 4 | 1 | 2.5 in |
| 2020 | 2 | 1 | 0 | 1 in |
| 2021 | 2 | 1 | 0 | 1 in |
| 2022 | 5 | 2 | 0 | 1 in |
| 2023 | 9 | 4 | 1 | 1.75 in |
| 2024 | 7 | 1 | 0 | 1 in |
| 2025 | 16 | 4 | 0 | 1 in |
2018 was the busiest year (45 reports) and 2016 the quietest (1). Boulder County averaged 7 reports a year from 2020 to 2025, 61% under the 18 of 2014 to 2019. Days with 1-inch stones average 2.5 per full year.
Boulder County: reports by month
| Jan | 0 |
|---|---|
| Feb | 0 |
| Mar | 0 |
| Apr | 0 |
| May | 29 |
| Jun | 52 |
| Jul | 40 |
| Aug | 13 |
| Sep | 10 |
| Oct | 2 |
| Nov | 0 |
| Dec | 0 |
June dominates the calendar: 52 of 146 reports, 36%. May to July alone bring 83%. 2 of 146 reports fell outside April to September.
Largest stone: 3 inches
Reported hail locations, Boulder County
- 881 to 1.74 in
- 211.75 to 2.74 in, golf ball to tennis ball
- 12.75 in and up, baseball
Largest plotted stone: 3 in. Bigger dots are bigger stones.
110 reports of 1 inch or larger have coordinates. Each dot is a reported location, not a storm path.
Sources: NOAA, Census county outlineBoulder County’s ten biggest hail days
| Date | Size | Reports | Place |
|---|---|---|---|
| June 18, 2018 | 3 in, a teacup | 23 | Superior |
| July 5, 2019 | 2.5 in, a tennis ball | 24 | Louisville |
| June 4, 2015 | 2.5 in, a tennis ball | 5 | Lyons |
| May 9, 2023 | 1.75 in, a golf ball | 4 | Longmont |
| September 11, 2019 | 1.5 in, a ping-pong ball | 9 | Lafayette |
| June 19, 2018 | 1.5 in, a ping-pong ball | 5 | Niwot |
| July 7, 2014 | 1.5 in, a ping-pong ball | 3 | Valmont |
| August 16, 2015 | 1.5 in, a ping-pong ball | 2 | Meeker Park |
| May 22, 2018 | 1.25 in, a half dollar | 7 | Longmont |
| August 14, 2018 | 1.25 in, a half dollar | 5 | Longmont |
“Severe thunderstorms produced large hail along the I-25 Corridor and adjacent plains. The hail ranged in size from quarter to tennis ball size, with the most damaging hail reported in Boulder and Larimer counties.”
NWS report, July 5, 2019
“Two large and long lived tornadoes developed in Larimer County near Berthoud and near Simla in Elbert County. The tornado that occurred along the Boulder and Larimer county line was rated an EF3 at it's highest damage point, with maximum winds estimated at 135 to 140 mph.”
NWS report, June 4, 2015
Tornadoes and wind in Boulder County
1 tornado on record in Boulder County; the strongest listed is EF3, 5.84 miles long, near Highland. Top gust: 72 mph near Longmont.
| Date | Rating | Path length | Width | Near |
|---|---|---|---|---|
| June 4, 2015 | EF3 | 5.84 mi | 440 yd | Highland |
| Date | Gust | Near |
|---|---|---|
| March 30, 2014 | 72 mph | Longmont |
| August 4, 2017 | 70 mph | Niwot |
| August 3, 2018 | 67 mph | Gold Hill |
| August 3, 2018 | 64 mph | Boulder |
| June 6, 2020 | 63 mph | Gold Hill |
| June 17, 2019 | 62 mph | Boulder Arpt |
Homes in Boulder County
Median build year in Boulder County: 1986. 74.9% of 142,809 homes predate 2000. Houses permitted since 2014: 7,730, or 54.1 per 1,000 homes. Busiest year: 2018.
| pre-1940 | 6.2% |
|---|---|
| 1940s | 1.4% |
| 1950s | 5.0% |
| 1960s | 9.9% |
| 1970s | 19.1% |
| 1980s | 14.7% |
| 1990s | 18.7% |
| 2000s | 12.5% |
| 2010s | 11.2% |
| 2020+ | 1.5% |
| Year | Houses | All units |
|---|---|---|
| 2014 | 560 | 1,371 |
| 2015 | 768 | 1,249 |
| 2016 | 716 | 1,849 |
| 2017 | 808 | 1,667 |
| 2018 | 899 | 2,954 |
| 2019 | 742 | 1,650 |
| 2020 | 573 | 1,634 |
| 2021 | 343 | 1,237 |
| 2022 | 661 | 1,642 |
| 2023 | 791 | 1,642 |
| 2024 | 441 | 1,680 |
| 2025 | 428 | 2,001 |
Quick answers
How many hail reports has Boulder County had?
NOAA logged 146 hail reports in Boulder County, Colorado, from 2014 to 2025.
How many days had hail of 1 inch or larger in Boulder County?
30 days, including 4 days with hail of 1.75 inches or larger. The National Weather Service calls hail of 1 inch or larger severe.
What was the largest hail reported in Boulder County?
3 inches (a teacup), reported on June 18, 2018.
Which month has the most hail in Boulder County?
June has the most reports, 36% of the 146 in the record.
Does a hail day in the record mean my roof was damaged?
A counted day only means a spotter reported hail somewhere in the area. An inspection is the only way to know whether a roof was hit.
Next steps for Boulder County
Boulder County cities we cover
Next to Boulder County in the Colorado ranking
- Larimer County (201 reports)
- Pueblo County (182 reports)
- Adams County (170 reports)
- Denver County (168 reports)
Cite this page
Data version: NOAA Storm Events hail data, 2014 to June 2026, loaded October 6, 2026. All dataset versions. Download the table as CSV. Free to quote with credit under CC BY 4.0.
Source: NOAA Storm Events Database, public domain. Counts and tables on this page are free to reuse with credit to PickARoofer under CC BY 4.0.