Contra Costa County, California: hazard history
What federal records show has already happened here: disaster declarations, storms, and flood insurance claims. This is a record of the past. It is not a forecast and not a hazard score.
At a glance
What this means
- The event NOAA recorded most often here is Strong Wind, with 202 records.
- The costliest single record is Flood in 2005: $22.0M in property damage, in the dollars of that year.
- The deadliest record is Heavy Rain in 2010, with 2 deaths.
- FEMA has declared 21 disasters that named this county, most often for flood.
- The worst year for flood insurance claims was 1982, with 139 claims.
What this can't tell you
- What happens next. Past events do not set the odds of the next one.
- Anything before 1996 from NOAA. That is when NOAA began recording every event type; earlier files hold only tornado, hail and wind, so they are left out on purpose.
- Today's cost. Damage and payments are in the dollars of the year they happened.
- A flood rate. NFIP counts claims but not how many homes were insured, and many flooded homes carry no flood insurance.
- Earthquakes, wildfire perimeters or radar-detected hail. Those records are not tied to counties.
Federal disaster declarations (FEMA)
FEMA declared 21 disasters that named Contra Costa County between 1969 and 2023.
| Incident type | Disasters | Most recent |
|---|---|---|
| Flood | 8 | 2023 |
| Severe Storm | 6 | 2017 |
| Biological | 2 | 2020 |
| Coastal Storm | 2 | 1983 |
| Drought | 1 | 1977 |
| Earthquake | 1 | 1989 |
| Hurricane | 1 | 2005 |
Most recent declarations
- EM-3591 2023 · Flood · Severe Winter Storms, Flooding, And Mudslides
- DR-4683 2022 · Flood · Severe Winter Storms, Flooding, Landslides, And Mudslides
- EM-3428 2020 · Biological · Covid-19
- DR-4482 2020 · Biological · Covid-19 Pandemic
- DR-4308 2017 · Flood · Severe Winter Storms, Flooding, And Mudslides
- DR-4305 2017 · Flood · Severe Winter Storms, Flooding, And Mudslides
- DR-4301 2017 · Severe Storm · Severe Winter Storms, Flooding, And Mudslides
- DR-1628 2005 · Severe Storm · Severe Storms, Flooding, Mudslides, And Landslides
- EM-3248 2005 · Hurricane · Hurricane Katrina Evacuation
- DR-1203 1998 · Severe Storm · Severe Winter Storms And Flooding
Not counted above: 34 statewide declarations, which covered every county in California. A declaration is a decision to send federal help, not a measure of how bad an event was. Records run from 1953. Source: FEMA OpenFEMA Disaster Declarations Summaries.
Storms recorded by NOAA, by type
| Event type | Records | Deaths | Injuries | Property damage |
|---|---|---|---|---|
| Strong Wind | 202 | 8 | 9 | $3.7M |
| High Wind | 72 | 1 | 1 | $3.2M |
| Flood | 59 | 0 | 0 | $44.3M |
| Heat | 29 | 2 | 12 | $30K |
| Dense Fog | 19 | 0 | 0 | $0 |
| Debris Flow | 15 | 0 | 0 | $12.9M |
| Wildfire | 13 | 0 | 0 | $5K |
| Flash Flood | 12 | 0 | 0 | $100K |
| Hail | 12 | 0 | 0 | $0 |
| Dense Smoke | 7 | 0 | 0 | $0 |
| Coastal Flood | 6 | 0 | 0 | $0 |
| Excessive Heat | 5 | 0 | 0 | $0 |
| Heavy Rain | 5 | 2 | 0 | $60K |
| Frost/Freeze | 4 | 0 | 0 | $20K |
| Thunderstorm Wind | 3 | 0 | 0 | $20 |
| Tornado | 3 | 0 | 0 | $275K |
| Cold/Wind Chill | 2 | 2 | 0 | $0 |
| High Surf | 1 | 0 | 0 | $0 |
| Tsunami | 1 | 0 | 0 | $50K |
| Winter Weather | 1 | 0 | 0 | $0 |
Records start in 1996. Damage is NOAA's estimate at the time, in nominal dollars, and is often rounded; it is not insurance claims data. A storm that crossed two NOAA zones in this county is recorded, and counted, once per zone. A storm filed against a forecast zone is counted in every county that zone covers, with the whole storm's damage; do not add these figures across counties.
Year by year
NOAA storm event records in Contra Costa County each year. The busiest year was 2019, with 74 records.
Show the numbers for every year
| Year | Records | Deaths | Property damage |
|---|---|---|---|
| 1996 | 1 | 0 | $0 |
| 1997 | 8 | 0 | $0 |
| 1998 | 5 | 0 | $250K |
| 2000 | 1 | 0 | $100K |
| 2002 | 1 | 0 | $0 |
| 2005 | 9 | 0 | $22.0M |
| 2006 | 8 | 0 | $33.0M |
| 2007 | 2 | 1 | $0 |
| 2008 | 9 | 0 | $70K |
| 2009 | 14 | 1 | $2.8M |
| 2010 | 17 | 2 | $822K |
| 2011 | 17 | 0 | $3.8M |
| 2012 | 9 | 1 | $442K |
| 2013 | 17 | 2 | $117K |
| 2014 | 23 | 0 | $79K |
| 2015 | 18 | 0 | $64K |
| 2016 | 1 | 0 | $1.0M |
| 2017 | 39 | 1 | $6K |
| 2018 | 41 | 0 | $5K |
| 2019 | 74 | 2 | $9K |
| 2020 | 31 | 0 | $1K |
| 2021 | 36 | 0 | $500 |
| 2022 | 24 | 2 | $20 |
| 2023 | 19 | 3 | $70 |
| 2024 | 19 | 0 | $70 |
| 2025 | 13 | 0 | $30 |
| 2026 | 15 | 0 | $10 |
Years with no record are left out of the table, not shown as zero.
Notable events
Costliest records
- Flood · Dec 31, 2005$22.0MNOAA name: Contra Costa County · NOAA record 5482521
- Flood · Jan 1, 2006$22.0MNOAA name: Contra Costa County · NOAA record 5486537
- Debris Flow · Apr 6, 2006$11.0MNOAA name: NWS forecast zone · NOAA record 5497356
- High Wind · Oct 13, 2009$2.5MNOAA name: NWS forecast zone · NOAA record 199983
- Debris Flow · Mar 24, 2011$1.6MNOAA name: NWS forecast zone · NOAA record 291539
Deadliest records
- Heavy Rain · Apr 11, 20102 deathsNOAA name: Contra Costa County · $10K damage · NOAA record 227063
- Cold/Wind Chill · Dec 2, 20222 deathsNOAA name: NWS forecast zone · NOAA record 1069470
- Heat · Jul 25, 20071 deathNOAA name: NWS forecast zone · NOAA record 38087
- Heat · Jun 27, 20091 deathNOAA name: NWS forecast zone · 1 injury · NOAA record 182325
- Strong Wind · Mar 15, 20121 deathNOAA name: NWS forecast zone · $13K damage · 4 injuries · NOAA record 373231
Each line is one NOAA record, linked to its page at NOAA. One large storm can appear more than once if NOAA recorded it in several zones of this county. Dollars are nominal.
Flood insurance claims (NFIP)
The National Flood Insurance Program paid $12.8M on 1,186 claims in Contra Costa County from 1978 to 2024.
| Year | Claims | Paid |
|---|---|---|
| 1982 | 139 | $563K |
| 1998 | 126 | $809K |
| 2005 | 94 | $1.8M |
| 1983 | 85 | $384K |
| 1995 | 75 | $357K |
A count of claims, not a rate: NFIP publishes no count of insured homes beside it, and most flood damage is uninsured. Nominal dollars. Records run from 1978 to 2024; claims filed without a county code are not on any county page. Source: FEMA OpenFEMA FIMA NFIP Redacted Claims.
Hazard vulnerability analysis: the probability column for a facility in Contra Costa County
A hazard vulnerability analysis rates each hazard for probability, impact, preparedness and response. Probability is the one column the county’s federal record can fill — NCEI storm events from 1996 to 2026 and FEMA declarations naming the county — and this is what it says for a facility here, on the 0–3 scale of the all-hazards structure surveyors expect. The other six columns are the facility’s own judgment about its building, and Calchis leaves them blank.
| Hazard | Prob. | Basis, from the county record |
|---|---|---|
| Hurricane / Tropical Storm | 3 | No events of this kind on the county's NCEI record over 31 years. 3 federal disaster declarations naming the county. |
| Severe Thunderstorm | 3 | 15 NCEI events over 31 years (0.48/yr). 6 federal disaster declarations naming the county. |
| Flood, External | 3 | 82 NCEI events over 31 years (2.65/yr). 8 federal disaster declarations naming the county. |
| Temperature Extremes | 3 | 40 NCEI events over 31 years (1.29/yr). No federal disaster declaration of this kind has named the county. |
| High Wind (non-convective) | 3 | 274 NCEI events over 31 years (8.84/yr). No federal disaster declaration of this kind has named the county. |
| Drought | 2 | No events of this kind on the county's NCEI record over 31 years. 1 federal disaster declaration naming the county. |
| Wild Fire | 2 | 13 NCEI events over 31 years (0.42/yr). No federal disaster declaration of this kind has named the county. |
| Earthquake | 2 | 1 federal disaster declaration naming the county. |
| Landslide | 2 | 15 NCEI events over 31 years (0.48/yr). No federal disaster declaration of this kind has named the county. |
| Epidemic | 2 | 2 federal disaster declarations naming the county. |
| Tornado | 1 | 3 NCEI events over 31 years (0.10/yr). No federal disaster declaration of this kind has named the county. |
| Snow Fall / Blizzard / Ice Storm | 1 | 1 NCEI event over 31 years (0.03/yr). No federal disaster declaration of this kind has named the county. |
| Tidal Wave / Tsunami | 1 | 1 NCEI event over 31 years (0.03/yr). No federal disaster declaration of this kind has named the county. |
| Volcano | 1 | No events of this kind on the county's NCEI record over 31 years. No federal disaster declaration of this kind has named the county. |
| Dam Inundation | 1 | No federal disaster declaration of this kind has named the county. |
A dash means the record does not speak to that hazard; it is not a zero. Whether a finished document satisfies the CMS Emergency Preparedness Rule is the facility’s finding and its surveyor’s. Complete the HVA for a facility in Contra Costa County — the technological, human and hazardous-materials rows, the six facility columns, the approval and the printed document — or read the sample analysis on that page first.
How this page was made
- Every figure is counted from public federal records held by Calchis: NOAA NCEI Storm Events, FEMA OpenFEMA Disaster Declarations, and FEMA NFIP claims. Nothing is modeled or estimated.
- NOAA files some events against a county and others against an NWS forecast zone, and publishes a code for both. Records are counted as Contra Costa County by that code — county records by the county's own FIPS code, zone records through the National Weather Service's published list of which counties each zone covers. No name matching is involved. Of 471 records, 103 were filed against this county and 368 against a forecast zone covering it. A zone storm is counted in every county its zone covers, and its damage figure is the whole storm's, not this county's share — NOAA does not publish that split. So these figures describe this county; they must not be added up across counties. Left out: 29% of California's NOAA records, which are marine zones or zones NWS does not map to a county.
- Counts last rebuilt from the source records on Sep 15, 2026.
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Recorded history from federal public records. Not a hazard score, a risk score, or a forecast, and not a substitute for professional actuarial or emergency-management assessment. Decision-support intelligence — not a primary alerting or dispatch system. Verify against official sources.