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Longmont hail storm history

Boulder County·NOAA NCEI Storm Events Database·~75-day publication lag

Longmont sits along Colorado's Front Range in Boulder County, a corridor where afternoon convective storms tracking northeast from the Rocky Mountains create consistent hail risk. The city's elevation and position relative to mountain-driven storm systems expose it to repeated warm-season hail events.

Events ≥1" (10yr)
80
Significant ≥1.5" (10yr)
20
Avg per year (10yr)
8.0
Largest recorded
2.5"
Most recent
Jun 26, 2025
Total records
102
NOAA storm history
events (10 yr)80
≥1.5" significant20
peak year (30)2018
Free inspection estimate

Check if your roof was damaged by recent hail

Type of damage

How urgent?

Hail risk in Longmont peaks between May and July, with secondary activity in April and August. Most significant events occur during afternoon hours between 2 p.m. and 7 p.m. Mountain Time, when atmospheric instability is highest and storms move through the region most rapidly.

Annual frequency — last 10 years

2025
2
2024
5
2023
10
2022
2
2021
2020
4
2019
27
2018
30
2017
2016
no events
≥2.0" severe≥1.5" significant≥1.0" marginal

When hail hits — monthly pattern

Avg events per month · all years · NOAA data

Jan0
Feb0
Mar0
Apr1
May28
Jun25
Jul10
Aug23
Sep14
Oct1
Nov0
Dec0

All recorded hail events

Of 102 recorded events, 20 (20%) reached 1.5" or larger — the threshold for likely functional damage on standard asphalt shingles.

Report from mping.

May 18, 20250.75"penny

Report from Mping.

Hail up to the size of a half dollar fell for a duration of 6 minutes.

Size was estimated.

Oct 1, 20221"quarter
Jul 26, 20220.75"penny
Jun 17, 20221"quarter
Apr 27, 20210.75"penny
Jul 31, 20201"quarter
Jun 9, 20200.75"penny
May 15, 20200.75"penny
Jul 9, 20191"quarter
Jun 9, 20190.75"penny
May 17, 20191"quarter
May 14, 20180.88"penny
Sep 16, 20170.75"penny
Data source

NOAA National Centers for Environmental Information Storm Events Database. Publication lag is approximately 75 days — current-year events may be incomplete.

NOAA Storm Events Database ↗