States › California › Contra Costa County

Contra Costa County, California

Recorded hazard history: storm events since 1950, federal disaster declarations since 1953, flood insurance claims since 1978, and FEMA's risk index.

FIPS 06013 · 1,161,413 residents (2021) · 717 sq mi · dominant hazard Flood

Hail · 14Tornado · 5Flood · 71Wind · 4Winter · 0

Contra Costa County within California. Dots: HailTornadoFloodWind event locations in the kept record. Boundaries: US Census Bureau.

NCEI notes that Storm Data is compiled from a variety of sources including the National Weather Service, other federal, state and local agencies, the media and the public; that property and crop damage figures are estimates; and that some events are recorded by NWS forecast zone rather than by county. FEMA notes that NFIP claim records are redacted and aggregated to protect the privacy of policyholders. NCEI storm records through 30 Jun 2026; OpenFEMA declarations refreshed 1 Oct 2026; NFIP claims as of 8 Sep 2026.

The NCEI record lists 108 events for Contra Costa County, California, between 1950 and 2026; floods and flash floods account for the largest share.

That is 15.1 events per 100 square miles, below the California figure of 26.2, and 0.9 per 10,000 residents against 10.4 statewide.

3 events fall in the 12 months to 30 Jun 2026. NCEI attributes 2 deaths and 1 injury to events in the county, with property damage estimated at $45M and crop damage at $50K.

FEMA has designated the county in 21 federal disaster declarations since 1953; the most recent is Severe Winter Storms, Flooding, Landslides, And Mudslides (major disaster, 14 Jan 2023).

National Flood Insurance Program policyholders in the county filed 1,202 claims since 1978, of which 669 were paid, totalling $13M (about $19K per paid claim). FEMA counts 2,681 residential flood policies in force.

FEMA's National Risk Index rates the county's overall risk as "Very High" and its expected annual loss as "Relatively High" ($971M a year across 18 hazards).

3events, last 12 monthsto 30 Jun 2026

108events since 19502 deaths, 1 injury recorded

21disaster declarationslast 14 Jan 2023

1,202NFIP flood claims$13M paid

Compared with California and the United States

Measure	Contra Costa County	California	US
Recorded events since 1950	108	40,849	1,977,440
Events per 100 square miles	15.1	26.2	56.0
Events per 10,000 residents	0.9	10.4	59.6
Events in the last 12 months	3	1,233	62,008
Deaths recorded by NCEI	2	1,170	26,435
Property damage (NCEI estimates)	$45M	$30B	$575B
NFIP claims per 1,000 residents	1.0	1.4	8.1
Average paid NFIP claim	$19K	$21K	$43K
Claims per 100 policies in force, last 10 years	6.3	5.0	16.1

County-recorded events plus zone-recorded events whose forecast zone is named for the county. State and US rows include events recorded only by forecast zone. Rates use 2021 Census population and land area.

Events by decade

Hail: 2Tornado: 2

Tornado: 2Flood: 12Wind: 1

Flood: 5

Hail: 11Tornado: 1Flood: 35Other: 14

Hail: 1Flood: 19Wind: 3

01950s01960s01970s41980s151990s52000s612010s232020s

Recorded events in Contra Costa County by decade and hazard group. HailTornadoFloodWindOther NCEI recorded only tornadoes, hail and thunderstorm wind before 1996.

Trend: 85 events in the 20 years to 2025 against 20 in the 20 years before. Reporting practice changed in 1996 and again with automated reports in the 2000s, so decade totals measure the record as much as the weather.

Events by type

Flood71

Hail14

Other14

Tornado5

Wind4

Hazard	Events	Deaths	Share of state's events
■ Flood	71	—	1.0%	detail
■ Hail	14	—	1.5%	detail
■ Other	14	2	0.4%
■ Tornado	5	—	1.0%
■ Wind	4	—	0.0%

Hazard pages exist for hail, tornado, flood, wind and winter where the county has at least 10 recorded events. "Other" covers heavy rain, debris flow, dust, funnel clouds and similar reports.

Largest recorded events

Date	Event type	Group	Magnitude	Property damage	Crop damage	Deaths	Injuries	Geography
11 Apr 2010	Heavy Rain	Other	—	$10K	—	2	1	County
31 Dec 2005	Flood	Flood	—	$22M	—	—	—	County
1 Jan 2006	Flood	Flood	—	$22M	—	—	—	County
2 Dec 2012	Flood	Flood	—	$250K	—	—	—	County
5 Dec 1998	Tornado	Tornado	F0	$200K	—	—	—	County
13 Feb 2000	Flash Flood	Flood	—	$100K	—	—	—	County

Ranked by deaths, then injuries, then NCEI's damage estimate. Deaths and injuries are NCEI counts (direct plus indirect); no personal details are recorded here.

Federal disaster declarations

Declared	Number	Type	Incident	Title	Programs
14 Jan 2023	DR-4683	Major disaster	Flood	Severe Winter Storms, Flooding, Landslides, And Mudslides	Individual assistance, Public assistance
9 Jan 2023	EM-3591	Emergency	Flood	Severe Winter Storms, Flooding, And Mudslides	Public assistance
22 Mar 2020	DR-4482	Major disaster	Biological	Covid-19 Pandemic	Individual assistance, Public assistance
13 Mar 2020	EM-3428	Emergency	Biological	Covid-19	Public assistance
1 Apr 2017	DR-4308	Major disaster	Flood	Severe Winter Storms, Flooding, And Mudslides	Public assistance
16 Mar 2017	DR-4305	Major disaster	Flood	Severe Winter Storms, Flooding, And Mudslides	Public assistance
14 Feb 2017	DR-4301	Major disaster	Severe Storm	Severe Winter Storms, Flooding, And Mudslides	Public assistance
3 Feb 2006	DR-1628	Major disaster	Severe Storm	Severe Storms, Flooding, Mudslides, And Landslides	Individual assistance, Public assistance
13 Sep 2005	EM-3248	Emergency	Hurricane	Hurricane Katrina Evacuation	Public assistance
9 Feb 1998	DR-1203	Major disaster	Severe Storm	Severe Winter Storms And Flooding	Individual assistance, Public assistance
4 Jan 1997	DR-1155	Major disaster	Severe Storm	Severe Storms, Flooding, Mud And Landslides	Individual assistance, Public assistance
12 Mar 1995	DR-1046	Major disaster	Severe Storm	Severe Winter Storms, Flooding Landslides, Mud Flow	Individual assistance, Public assistance
10 Jan 1995	DR-1044	Major disaster	Severe Storm	Severe Winter Storms, Flooding, Landslides, Mud Flows	Individual assistance, Public assistance
3 Feb 1993	DR-979	Major disaster	Flood	Severe Winter Storm, Mud & Land Slides, & Flooding	Individual assistance, Public assistance
18 Oct 1989	DR-845	Major disaster	Earthquake	Loma Prieta Earthquake	Individual assistance, Public assistance
21 Feb 1986	DR-758	Major disaster	Flood	Severe Storms & Flooding	Individual assistance, Public assistance
9 Feb 1983	DR-677	Major disaster	Coastal Storm	Coastal Storms, Floods, Slides & Tornadoes	Individual assistance, Public assistance
7 Jan 1982	DR-651	Major disaster	Flood	Severe Storms, Flood, Mudslides & High Tide	Individual assistance, Public assistance
1 Feb 1980	EM-3078	Emergency	Coastal Storm	Torrential Rain, High Tide & Winds	Public assistance
20 Jan 1977	EM-3023	Emergency	Drought	Drought	Public assistance
26 Jan 1969	DR-253	Major disaster	Flood	Severe Storms & Flooding	Individual assistance, Public assistance

Declarations in which FEMA designated this county, from the OpenFEMA Disaster Declarations Summaries (v2). DR: major disaster; EM: emergency; FM: fire management assistance. Programs show whether individual or public assistance was made available.

Flood insurance claims

197820022026

NFIP claims by year of loss in Contra Costa County, 1978 to 2026 (hover for the amount paid).

Claims since 19781,202

Paid claims669

Total paid$13M

Average paid claim$19K

Repetitive-loss properties768 severe

Residential policies in force2,6810.9% of 310,943 structures

Year of loss	Claims	Paid claims	Amount paid	Average paid
2026	1	1	$17,647	$17,647
2025	3	1	$3,508	$3,508
2024	5	2	$25,376	$12,688
2023	30	15	$757,341	$50,489
2022	38	32	$2,031,330	$63,479
2021	18	13	$561,838	$43,218
2019	12	4	$698,819	$174,705
2018	3	1	$12,835	$12,835
2017	60	36	$1,523,881	$42,330
2016	8	4	$12,319	$3,080
2015	1	0	$0	—
2014	7	3	$7,529	$2,510
2013	2	0	$0	—
2012	13	7	$265,030	$37,861
2011	7	0	$0	—
2010	7	4	$58,591	$14,648
2009	10	7	$218,005	$31,144
2008	10	4	$194,753	$48,688
2006	22	14	$276,482	$19,749
2005	94	73	$1,846,944	$25,301
2004	14	8	$57,200	$7,150
2003	3	1	$2,498	$2,498
2002	68	52	$1,216,884	$23,402
2001	12	4	$25,306	$6,326
2000	7	2	$2,076	$1,038

OpenFEMA NFIP claims (v3, as of 8 Sep 2026), aggregated by year of loss; amounts are building, contents and increased-cost-of-compliance payments as recorded. Repetitive-loss counts from the NFIP Multiple Loss Properties file (2 Aug 2026); policies in force from the NFIP Residential Penetration Rates file (3 Aug 2026).

National Risk Index

Overall riskVery Highscore 99.5 of 100

Expected annual loss$971MRelatively High

Social vulnerabilityRelatively Low

Community resilienceRelatively High

Hazard (NRI)	Risk rating	Expected annual loss
Earthquake	Relatively High	$518,775,051
Inland flooding	Very High	$412,454,327
Heat wave	Relatively High	$17,836,600
Wildfire	Relatively Moderate	$10,785,271
Drought	Relatively High	$2,845,788
Landslide	Relatively High	$2,368,650
Lightning	Relatively High	$1,457,728
Tornado	Relatively Low	$1,432,940
Tsunami	Relatively Low	$1,025,241
Coastal flooding	Relatively Moderate	$1,000,622
Strong wind	Relatively Low	$397,903
Hail	Very Low	$156,532
Winter weather	Very Low	$8,045
Volcanic activity	Very Low	$343
Avalanche	Very Low	$3

FEMA National Risk Index, December 2025 release. Ratings are FEMA's relative comparison of counties; expected annual loss is FEMA's modelled estimate of average yearly building, population and agriculture loss. See how to read the NRI.

Hurricane and tropical storm passes

No HURDAT2 track at tropical-storm strength passes within 100 miles of the county's centre point (through the 2025 season).

ZIP codes with flood claims

94553 187
94563 95
94806 80
94595 79
94549 72
94509 68
94596 67
94523 60
94803 40
94511 38
94507 31
94530 31
94804 31
94801 28
94526 26
94520 24
94583 23
94565 22
94505 21
94518 20
94561 19
94597 18
94514 17
94598 16
94521 14
94805 13
94513 11
94519 10
94556 10
94506 8
94572 8
94569 6
94517 5
94564 5

ZIP codes whose NFIP claims carry this county's code, with the number of claims. Five or more claims are needed for a ZIP page to be indexed.

Questions and answers

How often does it hail in Contra Costa County, CA?

NCEI records 14 hail events in Contra Costa County since 1950, in 4 different years; that is about 0.2 recorded events a year. 0 reports were golf-ball size (1.75 in) or larger.

Has Contra Costa County had a tornado?

Yes. NCEI records 5 tornadoes in Contra Costa County since 1950, 0 of them rated (E)F2 or stronger. Tornado deaths recorded: 0.

When was the last federal disaster declaration for Contra Costa County?

14 Jan 2023: Severe Winter Storms, Flooding, Landslides, And Mudslides, a major disaster declaration for flood. The county appears in 21 declarations since 1953.

How many flood insurance claims have been filed in Contra Costa County, and how much was paid?

1,202 NFIP claims since 1978, 669 of them paid, for $13M in total. FEMA publishes these figures redacted and aggregated; individual properties are not identified.

Is Contra Costa County in the National Risk Index's high-risk band?

FEMA's National Risk Index (December 2025) rates the county "Very High" for overall risk, "Relatively High" for expected annual loss, "Relatively Low" for social vulnerability and "Relatively High" for community resilience. These ratings are FEMA's relative comparison across all US counties.

How does Contra Costa County compare with the rest of California?

15.1 recorded events per 100 square miles against 26.2 statewide, and 1.0 NFIP claims per 1,000 residents against 1.4. The comparison table on this page shows each measure beside the state and national figures.

Provenance

Storm events: NOAA NCEI Storm Events Database, yearly details files through 30 Jun 2026 (public domain). Declarations: OpenFEMA DisasterDeclarationsSummaries v2, refreshed 1 Oct 2026. Flood claims: OpenFEMA NfipClaims v3 as of 8 Sep 2026; NfipMultipleLossProperties v1 (2 Aug 2026); NfipResidentialPenetrationRates v1 (3 Aug 2026). Risk index: FEMA National Risk Index, December 2025. Hurricane tracks: NHC HURDAT2 through 2025. Population and area: US Census Bureau, 2021 vintage. Built 1 Oct 2026; see the methodology and corrections pages. Hazard hubs: Hail · Tornado · Flood · Wind · Winter.