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Boulder County, CO hail & severe wind history
182 storm reports on file for Boulder County between 2010-04-21 and 2025-08-10 — 164 hail and 18 severe thunderstorm wind. That averages 11.4 reports a year, and Jun is the busiest month.
Hail reports
164
10.3 per year
Largest hail
3"
teacup size · 2018-06-18
Strongest gust
75 mph
65 kt · 2011-07-10
Reported damage
$0
property + crop, as filed
Storm days
60
distinct days with a report
Busiest year
2018
47 reports
Search every Boulder County report
Filter the full record below — pick a year, narrow to a month, or drag the hail-size slider to see only the storms big enough to dent a roof (1" and up is the usual threshold insurers care about).
182 of 182 reports match.
Reports by month for the current filter — the shape of Boulder County’s storm season.
| Date | Type | Size / gust | Nearest location | Report detail |
|---|---|---|---|---|
| 2025-08-10 18:08 | Hail | 0.88" nickel | 2.76 mi S of Niwot | No narrative filed · source: COOP Observer |
| 2025-08-10 18:10 | Hail | 0.75" penny | 2.76 mi S of Niwot | The report was from mPING. |
| 2025-08-10 18:13 | Hail | 1" quarter | 2.81 mi S of Niwot | The report was from mPING. |
| 2025-08-10 18:20 | Hail | 0.75" penny | 3.45 mi N of Lafayette | The report was from mPING. |
| 2025-08-10 18:25 | Hail | 0.75" penny | 2.07 mi N of Lafayette | The report was from mPING. |
| 2025-07-11 17:10 | Hail | 0.75" penny | 2.76 mi S of Niwot | No narrative filed · source: CoCoRaHS |
| 2025-07-11 17:27 | Hail | 1" quarter | 1.26 mi WNW of Louisville | No narrative filed · source: Trained Spotter |
| 2025-07-11 17:29 | Hail | 0.75" penny | 2.07 mi N of Louisville | No narrative filed · source: Public |
| 2025-07-11 17:42 | Hail | 0.75" penny | 2.14 mi SSW of Lafayette | No narrative filed · source: Public |
| 2025-06-17 01:23 | Hail | 0.75" penny | 2.14 mi NNE of Lafayette | Report from mping. |
| 2025-06-17 02:53 | Hail | 0.75" penny | 0 mi N of Lafayette | Report from mping. |
| 2025-06-17 12:48 | Hail | 1" quarter | 1.38 mi N of Louisville | No narrative filed · source: Trained Spotter |
| 2025-06-17 12:52 | Hail | 0.75" penny | 0 mi N of Lafayette | Report from mping. |
| 2025-06-17 12:57 | Hail | 1" quarter | 2.14 mi NNE of Lafayette | Report from mping. |
| 2025-05-18 14:15 | Hail | 0.75" penny | 2.11 mi NW of Marshall | Report from Mping. |
| 2025-05-18 14:16 | Hail | 1" quarter | 2.61 mi NW of Marshall | Picture of 1 inch hail on Twitter. |
| 2024-07-20 16:45 | Wind | 53 kt 61 mph | 3.79 mi WNW of Niwot | No narrative filed · source: Mesonet |
| 2024-07-20 19:03 | Hail | 0.75" penny | 2.07 mi N of Longmont | No narrative filed · source: Trained Spotter |
| 2024-05-30 19:55 | Hail | 0.75" penny | 2.14 mi NNE of Boulder Arpt | The report was from mping. |
| 2024-05-30 19:58 | Hail | 1" quarter | .53 mi W of Niwot | The report was from mping. |
| 2024-05-30 20:00 | Hail | 1" quarter | 0 mi N of Niwot | Size was estimated. |
| 2024-05-30 20:00 | Hail | 1" quarter | 3.16 mi NW of Lafayette | The report was from mping. |
| 2024-05-30 20:11 | Hail | 0.88" nickel | 1.26 mi WSW of Lafayette | No narrative filed · source: Trained Spotter |
| 2024-05-30 20:15 | Hail | 1" quarter | 3.45 mi N of Lafayette | The report was via mping. |
| 2023-07-31 17:57 | Wind | 53 kt 61 mph | 1.74 mi NW of Superior | No narrative filed · source: Mesonet |
| 2023-06-21 17:11 | Hail | 1" quarter | 2.61 mi SE of Boulder | No narrative filed · source: Trained Spotter |
| 2023-06-12 11:44 | Hail | 1" quarter | .69 mi S of Boulder | No narrative filed · source: Public |
| 2023-06-12 11:53 | Hail | 1" quarter | .53 mi W of Boulder | No narrative filed · source: Public |
| 2023-05-26 13:34 | Hail | 0.88" nickel | .87 mi NW of Longmont | No narrative filed · source: Public |
| 2023-05-26 13:35 | Hail | 1.25" half dollar | 2.61 mi NE of Longmont | No narrative filed · source: NWS Employee |
| 2023-05-09 21:35 | Hail | 1" quarter | 2.33 mi SSE of Longmont Muni Arpt | No narrative filed · source: Trained Spotter |
| 2023-05-09 21:38 | Hail | 1" quarter | 0 mi N of Niwot | No narrative filed · source: Trained Spotter |
| 2023-05-09 21:45 | Hail | 1" quarter | 2.14 mi NNW of Longmont | No narrative filed · source: CoCoRaHS |
| 2023-05-09 21:51 | Hail | 1.75" golf ball | .53 mi W of Longmont | No narrative filed · source: Public |
| 2022-10-01 14:26 | Hail | 0.75" penny | 1.06 mi W of Boulder Arpt | No narrative filed · source: Public |
| 2022-10-01 14:52 | Hail | 0.75" penny | 2.81 mi N of Lafayette | No narrative filed · source: Public |
| 2022-07-27 21:00 | Hail | 1" quarter | 2.76 mi S of Gold Hill | No narrative filed · source: Public |
| 2022-07-26 14:52 | Hail | 0.75" penny | 0 mi N of Niwot | No narrative filed · source: Trained Spotter |
| 2022-06-16 20:46 | Hail | 1" quarter | 0 mi N of Lyons | No narrative filed · source: Trained Spotter |
| 2021-06-25 13:00 | Hail | 1" quarter | 2.98 mi WNW of Boulder | No narrative filed · source: Trained Spotter |
| 2021-05-02 09:29 | Hail | 0.75" penny | 2.99 mi ENE of Nederland | No narrative filed · source: Public |
| 2020-07-31 16:32 | Hail | 1" quarter | 1.48 mi SSW of Longmont Muni Arpt | No narrative filed · source: Trained Spotter |
| 2020-06-08 21:37 | Hail | 0.75" penny | 2.81 mi S of Longmont | No narrative filed · source: Public |
| 2020-06-06 14:25 | Wind | 55 kt 63 mph | 3.25 mi ESE of Gold Hill | No narrative filed · source: Mesonet |
| 2020-06-06 14:40 | Wind | 52 kt 60 mph | 2.23 mi WNW of Louisville | Intense thunderstorm winds snapped tree limbs up to one inch in diameter. |
| 2019-09-11 15:27 | Hail | 1" quarter | 2.33 mi SSE of Longmont Muni Arpt | No narrative filed · source: Trained Spotter |
| 2019-09-11 15:27 | Hail | 1.5" ping pong | 2.81 mi N of Longmont | No narrative filed · source: Trained Spotter |
| 2019-09-11 15:28 | Hail | 1" quarter | .87 mi NW of Longmont | No narrative filed · source: Trained Spotter |
| 2019-09-11 15:30 | Hail | 1" quarter | 1.48 mi NNW of Longmont | No narrative filed · source: Trained Spotter |
| 2019-09-11 15:34 | Hail | 1" quarter | 1.73 mi WNW of Longmont | No narrative filed · source: Trained Spotter |
| 2019-09-11 15:37 | Hail | 1.25" half dollar | 1.74 mi NW of Longmont | No narrative filed · source: Trained Spotter |
| 2019-09-11 17:05 | Hail | 1" quarter | .87 mi NW of Louisville | No narrative filed · source: Amateur Radio |
| 2019-09-11 17:10 | Hail | 1.5" ping pong | 2.76 mi N of Lafayette | No narrative filed · source: Trained Spotter |
| 2019-09-11 18:12 | Hail | 1.5" ping pong | 2.76 mi N of Lafayette | No narrative filed · source: Trained Spotter |
| 2019-09-10 16:50 | Hail | 1" quarter | 2.73 mi ESE of Longmont | No narrative filed · source: Trained Spotter |
| 2019-08-13 20:44 | Hail | 0.88" nickel | 0 mi N of Longmont Muni Arpt | No narrative filed · source: Public |
| 2019-07-15 13:38 | Hail | 0.75" penny | 2.98 mi WNW of Boulder | No narrative filed · source: Trained Spotter |
| 2019-07-07 17:02 | Hail | 0.75" penny | 1.06 mi W of Louisville | No narrative filed · source: Amateur Radio |
| 2019-07-07 17:05 | Hail | 0.75" penny | 1.48 mi NNE of Louisville | No narrative filed · source: Public |
| 2019-07-05 18:12 | Hail | 1" quarter | .87 mi NW of Boulder | No narrative filed · source: Public |
| 2019-07-05 18:25 | Hail | 1.25" half dollar | 2.33 mi NNW of Marshall | No narrative filed · source: Trained Spotter |
| 2019-07-05 18:27 | Hail | 1" quarter | .53 mi W of Boulder | No narrative filed · source: Public |
| 2019-07-05 18:27 | Hail | 1" quarter | 1.26 mi ENE of Boulder | No narrative filed · source: Public |
| 2019-07-05 18:28 | Hail | 1.25" half dollar | 3.19 mi NNW of Louisville | No narrative filed · source: Public |
| 2019-07-05 18:34 | Hail | 1.25" half dollar | 1.26 mi ENE of Boulder | No narrative filed · source: Trained Spotter |
| 2019-07-05 18:35 | Hail | 1.25" half dollar | 2.14 mi SSE of Boulder | No narrative filed · source: Trained Spotter |
| 2019-07-05 18:39 | Hail | 1" quarter | 1.26 mi ENE of Boulder | No narrative filed · source: Public |
| 2019-07-05 18:40 | Hail | 1.75" golf ball | 3.19 mi NNW of Louisville | No narrative filed · source: Trained Spotter |
| 2019-07-05 18:45 | Hail | 1.75" golf ball | 1.48 mi NNW of Louisville | No narrative filed · source: Public |
| 2019-07-05 18:46 | Hail | 1.25" half dollar | .87 mi NW of Louisville | No narrative filed · source: Public |
| 2019-07-05 18:49 | Hail | 1.75" golf ball | 1.26 mi WSW of Lafayette | No narrative filed · source: Public |
| 2019-07-05 18:52 | Hail | 2.5" tennis ball | 2.14 mi NNE of Louisville | No narrative filed · source: Public |
| 2019-07-05 18:53 | Hail | 2" hen egg | 2.23 mi WNW of Louisville | No narrative filed · source: Public |
| 2019-07-05 18:54 | Hail | 1.75" golf ball | 1.48 mi NNW of Lafayette | No narrative filed · source: Trained Spotter |
| 2019-07-05 18:55 | Hail | 1.25" half dollar | .87 mi SW of Louisville | No narrative filed · source: Public |
| 2019-07-05 18:55 | Hail | 2" hen egg | 1.26 mi WSW of Lafayette | No narrative filed · source: Public |
| 2019-07-05 18:55 | Hail | 1" quarter | 2.07 mi S of Boulder Arpt | No narrative filed · source: Trained Spotter |
| 2019-07-05 18:58 | Hail | 1.5" ping pong | 2.98 mi ENE of Boulder Arpt | No narrative filed · source: Trained Spotter |
| 2019-07-05 19:15 | Hail | 1.75" golf ball | 1.74 mi NW of Lafayette | No narrative filed · source: Public |
| 2019-07-05 19:15 | Hail | 1" quarter | 2.96 mi NNE of Lafayette | No narrative filed · source: Public |
| 2019-07-05 19:28 | Hail | 1.25" half dollar | 2.14 mi NNW of Longmont | No narrative filed · source: Trained Spotter |
| 2019-07-05 19:34 | Hail | 1.25" half dollar | 2.61 mi NE of Hygiene | No narrative filed · source: Trained Spotter |
| 2019-07-05 19:37 | Hail | 1" quarter | .69 mi N of Longmont | No narrative filed · source: Public |
| 2019-06-28 19:55 | Wind | 50 kt 58 mph | 0 mi N of Longmont Muni Arpt | No narrative filed · source: AWOS |
| 2019-06-17 13:54 | Wind | 54 kt 62 mph | .87 mi NW of Boulder Arpt | No narrative filed · source: ASOS |
| 2019-06-08 14:40 | Hail | 0.75" penny | 3.17 mi E of Boulder Arpt | No narrative filed · source: Trained Spotter |
| 2019-06-08 14:50 | Hail | 1" quarter | 1.73 mi ESE of Louisville | No narrative filed · source: Trained Spotter |
| 2019-06-08 14:58 | Hail | 1" quarter | .87 mi SW of Louisville | No narrative filed · source: Trained Spotter |
| 2019-06-08 15:00 | Hail | 0.88" nickel | 1.38 mi S of Lafayette | No narrative filed · source: Trained Spotter |
| 2018-08-14 16:10 | Hail | 1.25" half dollar | 2.14 mi NNW of Longmont | No narrative filed · source: Public |
| 2018-08-14 16:12 | Hail | 1.25" half dollar | 1.74 mi SW of Longmont | No narrative filed · source: Trained Spotter |
| 2018-08-14 16:13 | Hail | 1.25" half dollar | 2.14 mi NNW of Longmont | No narrative filed · source: Public |
| 2018-08-14 16:15 | Hail | 1" quarter | 2.07 mi N of Longmont | No narrative filed · source: Trained Spotter |
| 2018-08-14 16:52 | Hail | 1.25" half dollar | 1.48 mi NNW of Longmont | No narrative filed · source: Public |
| 2018-08-03 19:00 | Wind | 56 kt 64 mph | 2.81 mi S of Boulder | No narrative filed · source: Mesonet |
| 2018-08-03 19:23 | Wind | 58 kt 67 mph | 2.14 mi SSE of Gold Hill | No narrative filed · source: Mesonet |
| 2018-07-25 17:45 | Hail | 1" quarter | 4.18 mi N of Lafayette | No narrative filed · source: Trained Spotter |
| 2018-06-19 11:18 | Hail | 1" quarter | 1.26 mi WNW of Niwot | No narrative filed · source: CoCoRaHS |
| 2018-06-19 11:40 | Hail | 1" quarter | 2.22 mi WNW of Niwot | No narrative filed · source: CoCoRaHS |
| 2018-06-19 11:43 | Hail | 1.25" half dollar | 2.14 mi SSW of Longmont | No narrative filed · source: Public |
| 2018-06-19 11:50 | Hail | 1.5" ping pong | 2.22 mi WNW of Niwot | No narrative filed · source: CoCoRaHS |
| 2018-06-19 12:01 | Hail | 1.25" half dollar | 2.14 mi SSE of Longmont Muni Arpt | No narrative filed · source: NWS Employee |
| 2018-06-18 16:58 | Hail | 1" quarter | 2.98 mi WNW of Boulder | No narrative filed · source: Public |
| 2018-06-18 17:00 | Hail | 1" quarter | 1.48 mi SSE of Boulder | No narrative filed · source: Emergency Manager |
| 2018-06-18 17:04 | Hail | 1.75" golf ball | 1.06 mi W of Boulder Arpt | No narrative filed · source: Public |
| 2018-06-18 17:08 | Hail | 1.5" ping pong | 1.38 mi S of Boulder | No narrative filed · source: Trained Spotter |
| 2018-06-18 17:10 | Hail | 1.25" half dollar | 1.48 mi SSE of Boulder | No narrative filed · source: Trained Spotter |
| 2018-06-18 17:10 | Hail | 1.75" golf ball | 1.26 mi WNW of Boulder Arpt | No narrative filed · source: Public |
| 2018-06-18 17:15 | Hail | 1.75" golf ball | 0 mi N of Boulder Arpt | No narrative filed · source: Public |
| 2018-06-18 17:35 | Hail | 1" quarter | 5.85 mi E of Niwot | No narrative filed · source: Social Media |
| 2018-06-18 18:20 | Hail | 1" quarter | 2.61 mi NW of Marshall | No narrative filed · source: NWS Employee |
| 2018-06-18 18:28 | Hail | 1" quarter | 2.14 mi NNW of Marshall | No narrative filed · source: Trained Spotter |
| 2018-06-18 18:31 | Hail | 3" teacup | 1.74 mi SE of Superior | No narrative filed · source: Trained Spotter |
| 2018-06-18 18:38 | Hail | 1.75" golf ball | 2.07 mi S of Boulder Arpt | No narrative filed · source: Public |
| 2018-06-18 18:39 | Hail | 1" quarter | 1.26 mi WNW of Louisville | No narrative filed · source: Trained Spotter |
| 2018-06-18 18:40 | Hail | 1.25" half dollar | 1.26 mi WNW of Louisville | No narrative filed · source: Trained Spotter |
| 2018-06-18 18:43 | Hail | 1.75" golf ball | 1.26 mi WNW of Louisville | No narrative filed · source: Trained Spotter |
| 2018-06-18 18:45 | Hail | 1.5" ping pong | 0 mi N of Lafayette | No narrative filed · source: CoCoRaHS |
| 2018-06-18 18:45 | Hail | 1" quarter | 1.38 mi N of Louisville | No narrative filed · source: NWS Employee |
| 2018-06-18 18:45 | Hail | 2" hen egg | 2.96 mi SE of Boulder Arpt | No narrative filed · source: Public |
| 2018-06-18 18:46 | Hail | 2" hen egg | 1.26 mi WNW of Louisville | No narrative filed · source: Social Media |
| 2018-06-18 18:49 | Hail | 2" hen egg | 1.73 mi ESE of Louisville | No narrative filed · source: Public |
| 2018-06-18 18:49 | Hail | 1" quarter | 2.14 mi NNE of Louisville | No narrative filed · source: Public |
| 2018-06-18 18:52 | Hail | 2.5" tennis ball | 1.26 mi WNW of Lafayette | No narrative filed · source: Trained Spotter |
| 2018-06-18 18:57 | Hail | 1.5" ping pong | 1.26 mi WSW of Lafayette | No narrative filed · source: Social Media |
| 2018-05-30 16:21 | Hail | 1" quarter | 1.38 mi N of Gold Hill | No narrative filed · source: Trained Spotter |
| 2018-05-22 16:20 | Hail | 1" quarter | 1.48 mi NNW of Longmont | No narrative filed · source: Storm Chaser |
| 2018-05-22 16:22 | Hail | 1.25" half dollar | 1.48 mi NNW of Longmont | No narrative filed · source: Trained Spotter |
| 2018-05-22 16:25 | Hail | 1" quarter | 2.61 mi SW of Highland | No narrative filed · source: Trained Spotter |
| 2018-05-22 16:30 | Hail | 0.88" nickel | 1.06 mi E of Longmont Muni Arpt | No narrative filed · source: Trained Spotter |
| 2018-05-22 16:30 | Hail | 0.75" penny | 2.14 mi NNW of Longmont | No narrative filed · source: Trained Spotter |
| 2018-05-22 17:35 | Hail | 0.75" penny | 4.18 mi N of Pinecliffe | No narrative filed · source: CoCoRaHS |
| 2018-05-22 17:57 | Hail | 0.75" penny | 0 mi N of Boulder | No narrative filed · source: Public |
| 2018-05-18 14:15 | Hail | 1" quarter | 2.07 mi S of Boulder | No narrative filed · source: Trained Spotter |
| 2018-05-18 14:17 | Hail | 0.75" penny | 2.33 mi NNW of Marshall | No narrative filed · source: CoCoRaHS |
| 2018-05-01 12:30 | Hail | 0.88" nickel | 2.33 mi SSE of Longmont Muni Arpt | No narrative filed · source: Trained Spotter |
| 2017-08-04 18:45 | Wind | 61 kt 70 mph | 5.33 mi E of Niwot | Intense thunderstorm winds snapped tree branches which knocked down power lines. |Power outages were reported along CO 52 near County Line Road. Outages were also reported in the vicinity CO 52 and CO 287. |
| 2017-05-17 18:25 | Hail | 0.75" penny | .87 mi SW of Boulder Arpt | No narrative filed · source: CoCoRaHS |
| 2017-05-16 13:30 | Hail | 0.88" nickel | 1.38 mi S of Boulder Arpt | No narrative filed · source: Trained Spotter |
| 2016-06-06 14:50 | Hail | 1" quarter | 3.8 mi NNW of Boulder | No narrative filed · source: Trained Spotter |
| 2015-08-16 13:50 | Hail | 1.5" ping pong | 0 mi N of Meeker Park | No narrative filed · source: CoCoRaHS |
| 2015-08-16 14:01 | Hail | 1.5" ping pong | .53 mi E of Meeker Park | No narrative filed · source: Trained Spotter |
| 2015-06-18 19:54 | Hail | 1" quarter | .69 mi S of Superior | No narrative filed · source: Trained Spotter |
| 2015-06-18 19:58 | Hail | 1" quarter | 1.26 mi WSW of Lafayette | No narrative filed · source: Public |
| 2015-06-18 20:01 | Hail | 1.25" half dollar | .87 mi SW of Louisville | No narrative filed · source: Public |
| 2015-06-04 18:03 | Hail | 2.5" tennis ball | 0 mi N of Lyons | No narrative filed · source: CoCoRaHS |
| 2015-06-04 18:13 | Hail | 2" hen egg | 1.38 mi N of Lyons | No narrative filed · source: CoCoRaHS |
| 2015-06-04 19:10 | Hail | 1.25" half dollar | 1.38 mi N of Longmont | No narrative filed · source: Trained Spotter |
| 2015-06-04 19:30 | Hail | 2.5" tennis ball | 0 mi N of Lyons | No narrative filed · source: CoCoRaHS |
| 2015-06-04 19:30 | Hail | 1" quarter | 2.14 mi NNW of Longmont | No narrative filed · source: CoCoRaHS |
| 2014-07-09 14:50 | Hail | 0.88" nickel | 2.11 mi E of Allens Park | No narrative filed · source: Trained Spotter |
| 2014-07-07 19:09 | Hail | 1.5" ping pong | 1.06 mi E of Valmont | No narrative filed · source: Trained Spotter |
| 2014-07-07 19:15 | Hail | 1.25" half dollar | .87 mi SW of Louisville | No narrative filed · source: Trained Spotter |
| 2014-07-07 19:18 | Hail | 1" quarter | .87 mi SW of Louisville | No narrative filed · source: Trained Spotter |
| 2014-05-07 16:27 | Hail | 1" quarter | .53 mi E of Ward | No narrative filed · source: Amateur Radio |
| 2014-03-30 20:57 | Wind | 63 kt 72 mph | 2.14 mi NNW of Longmont | No narrative filed · source: Mesonet |
| 2013-09-18 15:03 | Wind | 57 kt 66 mph | 1.26 mi ENE of Boulder | No narrative filed · source: Other Federal Agency |
| 2013-06-28 17:08 | Hail | 1" quarter | .53 mi W of Ward | No narrative filed · source: Trained Spotter |
| 2013-06-28 18:37 | Hail | 1.25" half dollar | 0 mi N of Lyons | No narrative filed · source: Trained Spotter |
| 2013-06-28 18:45 | Hail | 1.75" golf ball | 0 mi N of Lyons | No narrative filed · source: Trained Spotter |
| 2013-06-28 19:20 | Hail | 1.5" ping pong | 1.26 mi ENE of Boulder | No narrative filed · source: Public |
| 2013-06-28 19:57 | Hail | 1.75" golf ball | .53 mi W of Longmont | No narrative filed · source: Trained Spotter |
| 2013-06-28 19:58 | Hail | 1.5" ping pong | 1.73 mi ENE of Longmont | No narrative filed · source: Trained Spotter |
| 2013-06-28 20:57 | Hail | 1" quarter | 1.26 mi ENE of Boulder | No narrative filed · source: Trained Spotter |
| 2013-06-28 21:05 | Hail | 1" quarter | 2.33 mi NNW of Marshall | No narrative filed · source: Trained Spotter |
| 2012-09-03 16:05 | Wind | 52 kt 60 mph | 2.14 mi NNW of Longmont | No narrative filed · source: Trained Spotter |
| 2012-09-03 16:11 | Wind | 59 kt 68 mph | 1.74 mi NE of Hygiene | No narrative filed · source: Mesonet |
| 2011-07-13 18:17 | Hail | 1" quarter | 3.18 mi NNE of Lyons | No narrative filed · source: Trained Spotter |
| 2011-07-10 13:21 | Wind | 65 kt 75 mph | 1.48 mi SSE of Superior | No narrative filed · source: Mesonet |
| 2011-07-10 13:30 | Wind | 50 kt 58 mph | 2.11 mi SE of Louisville | No narrative filed · source: Trained Spotter |
| 2011-06-30 18:16 | Wind | 56 kt 64 mph | 1.38 mi N of Boulder Arpt | No narrative filed · source: ASOS |
| 2010-08-19 19:10 | Wind | 53 kt 61 mph | 1.06 mi W of Boulder | No narrative filed · source: Mesonet |
| 2010-08-19 19:23 | Wind | 54 kt 62 mph | 1.26 mi ESE of Boulder | No narrative filed · source: Trained Spotter |
| 2010-06-21 13:55 | Hail | 0.88" nickel | 1.59 mi W of Lafayette | No narrative filed · source: Trained Spotter |
| 2010-06-21 14:05 | Hail | 1" quarter | 1.48 mi NNW of Louisville | No narrative filed · source: Trained Spotter |
| 2010-06-21 14:06 | Hail | 1" quarter | .87 mi SW of Louisville | No narrative filed · source: Trained Spotter |
| 2010-06-11 14:43 | Hail | 1.75" golf ball | 1.74 mi NW of Lafayette | No narrative filed · source: Trained Spotter |
| 2010-05-26 19:41 | Hail | 1.5" ping pong | 1.26 mi WSW of Lafayette | No narrative filed · source: Trained Spotter |
| 2010-05-26 19:50 | Hail | 1" quarter | 1.26 mi WSW of Lafayette | No narrative filed · source: Trained Spotter |
| 2010-05-26 19:55 | Hail | 1" quarter | 1.26 mi WSW of Lafayette | No narrative filed · source: Trained Spotter |
| 2010-05-26 20:04 | Hail | 1.25" half dollar | 1.26 mi WSW of Lafayette | No narrative filed · source: Trained Spotter |
| 2010-04-21 16:50 | Hail | 0.88" nickel | 1.26 mi ENE of Boulder | No narrative filed · source: Trained Spotter |
Worst storm days in Boulder County
| Date | Reports that day | Largest hail | Peak gust |
|---|---|---|---|
| 2019-07-05 | 24 | 2.5" (tennis ball) | — |
| 2018-06-18 | 23 | 3" (teacup) | — |
| 2019-09-11 | 9 | 1.5" (ping pong ball) | — |
| 2013-06-28 | 8 | 1.75" (golf ball) | — |
| 2018-05-22 | 7 | 1.25" (half dollar) | — |
| 2024-05-30 | 6 | 1" (quarter) | — |
| 2015-06-04 | 5 | 2.5" (tennis ball) | — |
| 2018-06-19 | 5 | 1.5" (ping pong ball) | — |
| 2018-08-14 | 5 | 1.25" (half dollar) | — |
| 2025-08-10 | 5 | 1" (quarter) | — |
Reports by year
Report counts are driven partly by how many people were around to report a storm, so recent years tend to look busier than the early 2010s. Treat the trend as a reporting trend, not purely a weather trend.
Notable large-hail events (2" and up)
| Date | Size | Near | What was reported |
|---|---|---|---|
| 2019-07-05 | 2.5" tennis ball | 2.14 mi NNE of Louisville | No narrative filed |
| 2019-07-05 | 2" hen egg | 2.23 mi WNW of Louisville | No narrative filed |
| 2019-07-05 | 2" hen egg | 1.26 mi WSW of Lafayette | No narrative filed |
| 2018-06-18 | 3" teacup | 1.74 mi SE of Superior | No narrative filed |
| 2018-06-18 | 2" hen egg | 2.96 mi SE of Boulder Arpt | No narrative filed |
| 2018-06-18 | 2" hen egg | 1.26 mi WNW of Louisville | No narrative filed |
| 2018-06-18 | 2" hen egg | 1.73 mi ESE of Louisville | No narrative filed |
| 2018-06-18 | 2.5" tennis ball | 1.26 mi WNW of Lafayette | No narrative filed |
When does hail hit Boulder County?
Across 16 years of records, June produced the most reports (69), followed by the months either side of it. Monthly totals:
| Month | Reports | Share |
|---|---|---|
| January | 0 | 0.0% |
| February | 0 | 0.0% |
| March | 1 | 0.5% |
| April | 1 | 0.5% |
| May | 33 | 18.1% |
| June | 69 | 37.9% |
| July | 45 | 24.7% |
| August | 18 | 9.9% |
| September | 13 | 7.1% |
| October | 2 | 1.1% |
| November | 0 | 0.0% |
| December | 0 | 0.0% |
Nearby counties in Colorado
El Paso County (1,114)Weld County (725)Yuma County (704)Kit Carson County (612)Washington County (421)Logan County (415)Arapahoe County (378)Elbert County (354)Cheyenne County (338)Lincoln County (335)Adams County (307)Pueblo County (303)
See all 61 Colorado counties →
About these numbers
Every row above is a report filed with the National Weather Service and archived in the NOAA NCEI Storm Events Database (FIPS 8013). Reports are eyewitness, trained-spotter and damage-survey observations, so they cluster near roads and towns and miss storms over empty country. Hail sizes are estimates. Damage figures are preliminary as filed and are never revised in this archive. Use this page for background, not for an insurance claim, a legal filing, or a roof assessment — for those, get the official record from NOAA directly.