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Contra Costa County, California
Tornadoes, hail, floods and severe storms recorded here between 1983 and 2026, from NOAA's Storm Events Database. Search an address to see which tornadoes came closest to it.
5
Tornado reports
14
Hail reports
71
Floods since 1996
108
All events
2
Deaths
$44.8M
Property damage
Tornado paths in Contra Costa County
The part of each tornado’s path NOAA recorded in this county, 5 in all. Zoom in and the paths widen to their surveyed width.
EF0EF1EF2EF3EF4EF5Unrated
Year by year
All storm eventsTornadoes
NOAA's storm database records tornadoes back to 1950 and hail and thunderstorm wind back to 1955, but floods only from 1996 on. Older floods are missing here. For those, the U.S. Geological Survey's stream gauge records and flood reports are the place to look.
Most significant events
The strongest tornadoes, deadliest events and biggest damage here, up to 50.
A rain-slicked road led to the crash of a car at the intersection of Mount Diablo Boulevard and Iron Horse Regional Trail in Walnut Creek. The vehicle crashed through a fence and landed upside down in the rain-swollen San Ramon Creek bypass. The driver and one other individual pe…
Flood Flood
Flooding reported in one lane of southbound Interstate 680 south of Sycamore Valley Road.
Flood Flood
One foot of water was reported on westbound Interstate 580 just east of Canal Boulevard.
Flood Flood
The on and offramps from Canal Boulevard to Interstate 580 were flooded.
Flood Flood
A vehicle was reported stuck in floodwaters on westbound State Route 4 at the Franklin Canyon onramp. The onramp was also reported as flooded.
Flood Flood
Around 8 inches of water were reported on the ramp that connects eastbound State Route 24 to southbound Interstate 680.
Flood Flood
Flooding reported on eastbound Interstate 80 at Pinole Valley Road.
Flood Flood
Water was reported across all lanes of eastbound State Highway 24 at the junction with St Stephens Drive.
Flood Flood
Water was reported on all lanes of Westbound State Highway 24 at Camino Pablo.
Flood Flood
Flooding was blocking lanes on westbound Interstate 580 at Central Avenue.
Thunderstorm Wind Thunderstorm Wind
Powerlines were downed along Boulevard Way near Walnut Creek.
Thunderstorm Wind Thunderstorm Wind
Tree down in roadway along Danville Boulevard near Walnut Creek. Time estimated via radar.
Flood Flood
Roadway flooding was reported at Westbound California Highway 4 and Westbound Interstate 80.
Flood Flood
Significant flooding and runoff on Norris Canyon Road.
Flood Flood
Two to three feet of water flowing across the road at Camino Tassajara and Sherman Ranch Road.
Flood Flood
Slow lane starting to collapse with a crack approximately 10 feet long at the offramp from southbound Interstate 680 to El Pintado Road.
Flood Flood
The southbound lane of McEwen Road just south of California Highway 4 was completely blocked due to mud, dirt, and rock.
Flood Flood
A 6 inch deep puddle in the slow lane of westbound Interstate 80.
Flood Flood
Flooding was reported at SB 160 over Main Street. Lane 1 was partially flooded with 2 inches of water.
Flood Flood
The roof of a Big 5 Sporting Goods store in San Ramon caved in the early morning hours of the 27th after a main beam broke in the center of the store. Local officials from the San Ramon Valley Protection District stated that they believed heavy rain was a factor in the roof colla…
Thunderstorm Wind Thunderstorm Wind
Mesonet station at Shadowhawk reported wind gusts over 60 mph.
Hail Hail
Spotter reporting pea-sized hail near San Ramon.
Flood Flood
Roadway flooding at SR-4 W and Alhambra Ave off ramp. Flooding across entire slow lane.
Flood Flood
Roadway flooding at I-680 S and Crow Canyon Rd off ramp. Vehicles hydroplaning.
Flood Flood
CHP reports several freeways including 680 and 24 have flooding in some or all lanes.
Flood Flood
Media reported flooded roads at the intersection of Broadway and Cypress St in Walnut Creek.
Flood Flood
Roadway flooding at I-680 S and Concord Ave off ramp, both lanes flooded.
Flood Flood
Roadway flooding at SR-24 E and Saint Stephens Dr off ramp.
Flood Flood
Right hand side and slow lane water on roadway of SB 680 junction with Treat Blvd.
Hail Hail
Accumulating hail reported on the 680 corridor in Contra Costa.
Flood Flood
On ramp from Canal Blvd to I-580 E flooded with 1-1.5 feet of water.
Flood Flood
Roadway flooding reported.
Debris Flow Debris Flow
Mud and rocks in roadway at Bailey Rd and Keller Canyon, mud coming down hill blocking left lane.
Flood Flood
Vehicles getting stuck in water at Arthur Rd and Pacheco Blvd.
Flood Flood
Contra Costa County Public Works is working to drain flood waters on Judith Court.
Debris Flow Debris Flow
SB 4 McEwen Rd on ramp, side of hillside slid down and is blocking roadway.
Flood Flood
Water covering two lanes 7 inches deep.
Debris Flow Debris Flow
Mud flow along hillside at Bollinger Canyon Rd just west of Bear Tree Road crossing westbound lanes.
Flood Flood
Roadway flooding at SR 24E at Acalanes Rd.
Flood Flood
Roadway flooding reported at I680 N and Olympic Blvd on ramp, 8-10 inches of water in number 2 lane.
Hail Hail
Small hail along with thunder and lightning reported in Orinda.
Hail Hail
Small hail reported in southern Contra Costa county.
Flood Flood
I-80 E adjacent to the Pomona on ramp, 2 feet of water in number 1 lane.
Hail Hail
Hail Hail
Hail Hail
Hail Hail
Hail Hail
Accumulating hail reported in Kensington.
Events by year, as a table
| Year | Events | Tornadoes |
|---|---|---|
| 2026 | 1 | 0 |
| 2025 | 4 | 0 |
| 2024 | 13 | 0 |
| 2022 | 1 | 0 |
| 2020 | 4 | 0 |
| 2019 | 15 | 0 |
| 2018 | 18 | 0 |
| 2017 | 18 | 0 |
| 2015 | 1 | 0 |
| 2012 | 3 | 0 |
| 2011 | 1 | 0 |
| 2010 | 5 | 1 |
| 2009 | 1 | 0 |
| 2006 | 1 | 0 |
| 2005 | 1 | 0 |
| 2002 | 1 | 0 |
| 2000 | 1 | 0 |
| 1998 | 5 | 2 |
| 1997 | 8 | 0 |
| 1996 | 1 | 0 |
| 1994 | 1 | 0 |
| 1989 | 2 | 2 |
| 1983 | 2 | 0 |
Search your address
See every tornado that passed within 25 miles of a place in Contra Costa County, measured to its path.
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