Hail history in Boulder, CO
On average, NOAA recorded hail within 15 miles of the center of Boulder on 5.0 days a year from 2016 to 2025, 3.5 of them with hail 1 inch or larger. NOAA recorded hail within 15 miles of the center of Boulder on 69 days since 2010. The largest hail reported was 3.0 in, in 2018. 48 of those days had hail of 1 inch or larger. May has the most hail days, 20 since 2010. The most recent was July 28, 2026. NOAA also recorded high wind on 23 days, with gusts up to 81 mph.
Ranks #19 of 200 US cities for days with hail 1 inch or larger, 2016 to 2025.
- Hail days since 2010
- 69
- Largest hail
- 3.0 in
- Highest gust
- 81 mph
Source: NOAA/NWS Storm Prediction Center
Data through November 1, 2026
69 hail days within 15 miles since 2010, largest 3.0 in
Source: NOAA/NWS Storm Prediction Center
Data through November 1, 2026
Hail days by year
Bar chart of hail days per year, 2010 to 2026. 69 hail days in total; the most was 11 in 2019.
Hail days by month
Hail days by month since 2010: Jan 0, Feb 0, Mar 0, Apr 1, May 20, Jun 18, Jul 17, Aug 9, Sep 3, Oct 1, Nov 0, Dec 0.
Most recent hail days
| Date | Largest hail | Nearest report |
|---|---|---|
| Jul 28, 2026 | 1.0 in | 14.2 mi |
| Jun 26, 2026 | 1.0 in | 14.6 mi |
| Aug 23, 2025 | 0.75 in | 10.7 mi |
| Aug 10, 2025 | 1.0 in | 5.0 mi |
| Jul 11, 2025 | 1.0 in | 5.0 mi |
| Jun 17, 2025 | 1.0 in | 6.6 mi |
| Jun 16, 2025 | 0.75 in | 9.2 mi |
| May 18, 2025 | 1.0 in | 3.1 mi |
| May 14, 2025 | 1.25 in | 10.2 mi |
| Jul 20, 2024 | 1.0 in | 14.1 mi |
About this data
- Distances are from the center of Boulder, not from any one property. Look up a street address below for a single building.
- Reports come from trained spotters and the public, so they cluster near towns and roads.
- No report does not mean no hail. Hail can fall where no one is there to report it.
- This is not a damage or insurance assessment.
23 high-wind days within 15 miles since 2010, strongest gust 81 mph
Source: NOAA/NWS Storm Prediction Center
Data through November 1, 2026
Most recent high-wind days
| Date | Highest gust | Nearest report |
|---|---|---|
| Aug 30, 2026 | 60 mph | 10.7 mi |
| Jul 24, 2026 | 70 mph | 10.7 mi |
| Jul 10, 2025 | 64 mph | 9.4 mi |
| Jun 17, 2025 | 60 mph | 14.6 mi |
| Jul 20, 2024 | 61 mph | 7.4 mi |
| Jul 31, 2023 | 61 mph | 5.0 mi |
| Jun 25, 2020 | 60 mph | 10.7 mi |
| Jun 24, 2020 | 67 mph | 10.7 mi |
| Jun 6, 2020 | 71 mph | 4.9 mi |
| Jun 28, 2019 | 58 mph | 10.9 mi |
About this data
- Distances are from the center of Boulder, not from any one property. Look up a street address below for a single building.
- Reports come from trained spotters and the public, so they cluster near towns and roads.
- No report does not mean no hail. Hail can fall where no one is there to report it.
- Wind speed is the highest reported gust; some reports have no speed.
- This is not a damage or insurance assessment.
Gusts, tornadoes and hurricanes in Boulder
Estimated peak gusts
22 days since October 1, 2021 had an estimated peak gust of 58 mph or more at Boulder.
| Day | Estimated peak gust |
|---|---|
| Mar 17, 2026 | 50 mph or more |
| Mar 14, 2026 | 50 mph or more |
| Mar 12, 2026 | 58 mph or more |
| Jan 6, 2026 | 58 mph or more |
| Jan 5, 2026 | 50 mph or more |
| Dec 25, 2025 | 50 mph or more |
| Dec 22, 2025 | 58 mph or more |
| Dec 19, 2025 | 80 mph or more |
Show all 42Show fewer
| Day | Estimated peak gust |
|---|---|
| Dec 17, 2025 | 90 mph or more |
| Oct 20, 2025 | 50 mph or more |
| May 15, 2025 | 70 mph or more |
| Mar 24, 2025 | 50 mph or more |
| Mar 17, 2025 | 50 mph or more |
| Mar 16, 2025 | 50 mph or more |
| Feb 2, 2025 | 58 mph or more |
| Jan 21, 2025 | 50 mph or more |
| Dec 30, 2024 | 50 mph or more |
| Aug 11, 2024 | 50 mph or more |
| Jun 17, 2024 | 50 mph or more |
| May 25, 2024 | 50 mph or more |
| May 23, 2024 | 58 mph or more |
| May 6, 2024 | 80 mph or more |
| Apr 15, 2024 | 50 mph or more |
| Apr 7, 2024 | 70 mph or more |
| Apr 6, 2024 | 80 mph or more |
| Feb 25, 2024 | 58 mph or more |
| Feb 24, 2024 | 50 mph or more |
| Jan 18, 2024 | 58 mph or more |
| Jan 10, 2024 | 58 mph or more |
| Dec 7, 2023 | 58 mph or more |
| Dec 2, 2023 | 58 mph or more |
| Mar 31, 2023 | 70 mph or more |
| Mar 30, 2023 | 58 mph or more |
| Feb 20, 2023 | 80 mph or more |
| Jan 10, 2023 | 50 mph or more |
| Dec 8, 2022 | 50 mph or more |
| Dec 1, 2022 | 58 mph or more |
| Apr 22, 2022 | 50 mph or more |
| Apr 12, 2022 | 50 mph or more |
| Dec 30, 2021 | 80 mph or more |
| Dec 15, 2021 | 70 mph or more |
| Nov 16, 2021 | 50 mph or more |
Estimates: the highest gust of each storm day in NOAA’s hourly 2.5 km wind analysis (URMA), which fills in between weather stations. Analyses like this smooth out short thunderstorm gusts, so they are best for widespread wind (hurricanes, winter storms, high wind days); for thunderstorm wind, NOAA’s wind reports are the better record. Not a measurement at any building.
Tornadoes within 10 miles
NOAA recorded 6 tornadoes whose path came within 10 miles of Boulder since 1950; the strongest was rated EF2.
| Day | Rating | Path length | Closest |
|---|---|---|---|
| Jun 6, 1997 | EF1 | 0.1 miles | 3.3 miles |
| Jun 1, 1990 | EF0 | 0.2 miles | 3.9 miles |
| Oct 15, 1980 | EF2 | 1.5 miles | 1.7 miles |
| Apr 30, 1980 | EF1 | 5.7 miles | 9.1 miles |
| Jun 4, 1976 | EF0 | 0.1 miles | 9.2 miles |
| Sep 17, 1953 | EF1 | 0.1 miles | 2 miles |
Source: NOAA/NWS Storm Prediction Center. Ratings before 2007 are on the original Fujita scale.
Hurricanes and tropical storms
No hurricane or tropical storm in NOAA's records brought modeled tropical-storm-force winds (39 mph) to Boulder.
Modeled from NOAA’s best tracks for open, flat ground; not measurements. How we model hurricane winds
56 radar hail days within 15 miles since 2020, largest 3.0 in or more
Source: NOAA MRMS radar (MESH), from October 14, 2020. Estimates of the largest hail in each 1 km cell, not measurements.
33 days with radar hail 1 inch or larger, 3 at 2 inches or larger, within 15 miles of Boulder’s center.
Biggest radar hail days
- 0.75 in+
- 1.0 in+
- 1.5 in+
- 2.0 in+
- 2.5 in+
- 3.0 in+
Most recent radar hail days
| Date | Largest radar estimate |
|---|---|
| Sep 6, 2026 | 0.75 in or more |
| Jul 28, 2026 | 1.5 in or more |
| Jul 24, 2026 | 1.75 in or more |
| Jul 9, 2026 | 1.0 in or more |
| Jul 1, 2026 | 0.75 in or more |
| Jun 26, 2026 | 1.25 in or more |
Storms in Boulder
Hail falls more often in the lee of the Rockies than anywhere else in North America, per an information sheet by Nolan Doesken, then Colorado State Climatologist.1 Colorado Climate Center data show severe hail reports in Colorado peak in mid-June, and days with severe thunderstorm wind gusts peak in early to mid-July.2 Boulder is often hit by strong downslope winds, especially in winter, when upper-level westerlies rush down from the Continental Divide, per NCAR.3
Notable storms
- December 17, 2025From December 17 to 19, 2025, high winds gusted to 100 mph or more in and near the foothills. NWS Boulder logged a 91 mph gust in Boulder on the 17th and 112 mph 3 miles northwest of Marshall on the 19th. Trees and streetlights fell in Boulder County, Boulder Reporting Lab reported.4,5
- May 9, 2023Late on May 9, 2023, severe storms dropped hail up to 1.75 inches across in Longmont and 2 inches in Erie. NOAA's storm records note extensive damage to homes and vehicles in Longmont, Erie, Johnstown and Firestone.6,7
- December 30, 2021On December 30, 2021, a mountain wave drove gusts of 70 to 100 mph along the base of the foothills, including Boulder, and fanned the Marshall Fire east into Superior and Louisville. NWS Boulder noted an 85 mph gust in south Boulder and a 115 mph peak gust just east of Highways 93 and 72.8
- July 5, 2019On the evening of July 5, 2019, storms dropped hail up to 1.25 inches across in Boulder and 2.5 inches near Louisville. NOAA's storm records say the hail that day ran from quarter to tennis ball size, with the most damaging hail in Boulder and Larimer counties.9,10
- June 18, 2018On June 18, 2018, storms across the northern Front Range dropped golf ball to baseball size hail, per NWS Boulder. NOAA's storm records include 3-inch hail near Superior and 2.5-inch hail near Lafayette.11,12,13
- January 17, 1982On January 17, 1982, a Chinook windstorm brought a 137 mph gust at NCAR's Table Mesa lab in southwest Boulder. NCEI calls it one of the worst windstorms in the area's recorded history.14,3
Warnings and alerts
BOCO Alert, run by the Boulder Office of Disaster Management, sends emergency alerts by text, phone call and email to people who register at bocoalert.org.15
Sources
- 1. CoCoRaHS / Colorado Climate Center: Information Sheet on Hail in Colorado
- 2. Colorado Climate Center: Ramping up to peak severe thunderstorm and tornado season in Colorado
- 3. NCAR & UCAR News: Boulder's winds aren't what they used to be
- 4. NWS Denver/Boulder: High Wind Reports from 12/17/2025 through 12/19/2025
- 5. Boulder Reporting Lab: After two Xcel power shutoffs in a week, thousands in Boulder without power as questions mount
- 6. NOAA NCEI Storm Events Database: Hail, Boulder County, May 9, 2023 (Longmont)
- 7. NOAA NCEI Storm Events Database: Hail, Weld County, May 9, 2023 (Erie)
- 8. NWS Denver/Boulder: Marshall Fire and High Wind on December 30 2021
- 9. NOAA NCEI Storm Events Database: Hail, Boulder County, July 5, 2019 (Boulder)
- 10. NOAA NCEI Storm Events Database: Hail, Boulder County, July 5, 2019 (Louisville)
- 11. NWS Denver/Boulder: June 18th Hail Storm
- 12. NOAA NCEI Storm Events Database: Hail, Boulder County, June 18, 2018
- 13. NOAA NCEI Storm Events Database: Hail, Boulder County, June 18, 2018 (Lafayette)
- 14. NOAA NCEI: Weather History: Chinook Winds of Winter 1982
- 15. Boulder Office of Disaster Management: BOCO Alert
Free hail history
See the hail history near your property.
Enter a street address to see every day since 2010 with NOAA hail and wind reports within 10 miles.
Get a hail report for your whole portfolio.
Send us your properties and we’ll pull the NOAA hail history for every address. Then Cloudbreak watches each one, and you hear from us when a storm tracks toward it.
Questions about hail in Boulder
Source: NOAA/NWS Storm Prediction Center
Data through November 1, 2026
- How often does it hail in Boulder?
- NOAA recorded hail within 15 miles of the center of Boulder on 5.0 days a year on average from 2016 to 2025, 3.5 of them with hail 1 inch or larger. Since 2010 it recorded 69 hail days.
- When is hail season in Boulder?
- May has the most hail days within 15 miles of the center of Boulder, 20 since 2010, then June (18) and July (17).
- What is the largest hail recorded in Boulder?
- 3.0 in, in 2018: the largest hail NOAA recorded within 15 miles of the center of Boulder since 2010.
- When did it last hail in Boulder?
- NOAA's most recent hail report within 15 miles of the center of Boulder is from July 28, 2026, with hail up to 1.0 in reported 14.2 miles from the center. Data through November 1, 2026.