Hail history for Boulder County, CO

Boulder County has 356 recorded hail events in the NOAA Storm Events Database — 230 of them 1″ or larger and 24 at 2″ or larger. The largest on record: 3.0″ (tea cup) on June 18, 2018.

Records 1950–present Data through April 2026 Peak month June

Core sample · every recorded event, 1955–2026

Mark size = measured hail diameter; slivers are events with no recorded size. Amber ≥2″, red ≥2.75″ (baseball class). Denser recent decades partly reflect better reporting, not only more storms.

Recorded events 356 since 1962

1″ or larger 230 NWS severe threshold

2″ or larger 24 hen egg class and up

Largest recorded 3.0″ tea cup · June 18, 2018

Read the record honestly: Storm Events contains what was reported to the National Weather Service. Sparse or rural counties under-report, and coverage improved sharply after the mid-1990s — a quiet-looking stretch is not proof nothing fell.

When it hails in Boulder County

Recorded events by month, 1950–present. The amber bar marks Boulder County's peak: June.

Most recent recorded events

Latest 8 of 356 recorded events · data through April 2026
Date	Size	Comparable to
August 10, 2025	0.75″	Penny
August 10, 2025	0.75″	Penny
August 10, 2025	1.0″	Quarter
August 10, 2025	0.88″	Nickel
August 10, 2025	0.75″	Penny
July 11, 2025	0.75″	Penny
July 11, 2025	0.75″	Penny
July 11, 2025	1.0″	Quarter

Looking for a specific storm? Use the did-it-hail date lookup for Boulder County.

From the storm reports

Narratives as filed with the NOAA Storm Events Database (public records; lightly trimmed for length).

August 10, 2025 · 0.75″ (penny)

The report was from mPING.

June 24, 2006 · 2.5″ (tennis ball)

Large hail broke a car windshield.

Events by decade

1950s	1960s	1970s	1980s	1990s	2000s	2010s	2020s
0	12	11	38	56	75	123	41

The climb across decades is largely a reporting story: spotter networks, radar, and digital filing pulled far more storms into the record after the 1990s.

Questions about hail in Boulder County

Has it ever hailed in Boulder County?

Yes — 356 hail events have been recorded for Boulder County, CO in the NOAA Storm Events Database since 1962, including 230 of 1″ (quarter size) or larger.

When did it last hail in Boulder County?

The most recent recorded hail event for Boulder County, CO is August 10, 2025, with 0.75″ (penny) hail. The database is currently updated through April 2026, so a storm from the last few weeks may not appear yet. To check a specific day, use the did-it-hail date lookup.

What is the largest hail ever recorded in Boulder County?

3.0″ (tea cup), recorded on June 18, 2018. Hail that size is destructive-class and typically damages roofs, vehicles, and siding. See how big that really is on the actual-size hail chart.

Does a recorded hail event mean my roof was damaged?

No. This page reports storm records, not damage. Hail size and damage vary block by block within a county, and only an inspection can establish what happened to a specific roof. If you suspect damage, talk to your insurer or a licensed roofer — they can pull the same NOAA records for your claim.

More Colorado hail history

All 64 Colorado counties, ranked by recorded hail →

Source: NOAA/NCEI Storm Events Database, public domain, updated monthly by NCEI — this site's copy runs through April 2026. HailHistory reports records; it does not give insurance advice or assess damage.