HailHistory › Hail by county › California › Contra Costa County
California · county FIPS 06013
Hail history for Contra Costa County, CA
Contra Costa County has 14 recorded hail events in the NOAA Storm Events Database — 0 of them 1″ or larger. The largest on record: 0.75″ (penny) on April 29, 1983.
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.
When it hails in Contra Costa County
Recorded events by month, 1950–present. The amber bar marks Contra Costa County's peak: March.
Most recent recorded events
| Date | Size | Comparable to |
|---|---|---|
| 0.25″ | Pea | |
| 0.25″ | Pea | |
| 0.25″ | Pea | |
| 0.25″ | Pea | |
| 0.25″ | Pea | |
| 0.25″ | Pea | |
| 0.5″ | Mothball | |
| 0.25″ | Pea |
Looking for a specific storm? Use the did-it-hail date lookup for Contra Costa County.
From the storm reports
Narratives as filed with the NOAA Storm Events Database (public records; lightly trimmed for length).
· 0.25″ (pea)
Spotter reporting pea-sized hail near San Ramon.
· 0.25″ (pea)
Accumulating hail reported on the 680 corridor in Contra Costa.
Events by decade
| 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|
| 0 | 0 | 0 | 2 | 0 | 0 | 11 | 1 |
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 Contra Costa County
Has it ever hailed in Contra Costa County?
Yes — 14 hail events have been recorded for Contra Costa County, CA in the NOAA Storm Events Database since 1983, including 0 of 1″ (quarter size) or larger.
When did it last hail in Contra Costa County?
The most recent recorded hail event for Contra Costa County, CA is April 6, 2020, with 0.25″ (pea) 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 Contra Costa County?
0.75″ (penny), recorded on April 29, 1983. Hail that size is below the National Weather Service 1″ severe threshold. 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 California hail history
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.