Colusa County
Population 21,836 (2025) 1,151 sq mi
Large wildfires have burned 167,427 acres of Colusa County since 1984, 36th most of 58 counties in California; the largest was the Ranch Fire in 2018.
Hazard fingerprint Each spoke is this county’s percentile among U.S. counties where that hazard occurs. How it is computed
- Tornado damage paths since 19504
- Wildfire burn scars since 198418
- Major flood years since 19782
At a glance
The record for Colusa County in eight numbers. Each links to its section below.
Acres burned since 1984
167,427
36th of 58 in California
18 large fires; the largest was Ranch, 2018
DetailsTornadoes since 1950
4
30th of 58 in California
About as many as the typical California county
DetailsStrongest tornado
EF0
March 23, 2011, 1.1 mile path
Federal disaster declarations
19
Most recent: Severe Winter Storms, Flooding, Landslides, and Mudslides, 2023
DetailsTornadoes
About one every 19 years since 1950, none rated F3/EF3 or stronger.
Strongest
March 23, 2011
EF0, 1.1 mile path
10 yards wide.
Most recent
Saturday, February 2, 2019
EF0, 0.1 mile path
7 years ago.
Every recorded tornado
| Feb 2, 2019 | EF0 | 0.1 | 0 | 0 |
| Feb 19, 2013 | EF0 | 0.3 | 0 | 0 |
| Mar 23, 2011 | EF0 | 1.1 | 0 | 0 |
| Mar 21, 2011 | EF0 | 0.2 | 0 | 0 |
- Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Colusa County: 0.
- Weak tornadoes were under-recorded before Doppler radar coverage became national in the early 1990s, so earlier decades read low. Ratings use the Fujita scale before February 2007 and the Enhanced Fujita scale after.
Storm Prediction Center severe weather database, 1950 to 2025.
Hurricanes and tropical storms
No tropical storm or hurricane has tracked within 100 miles since records began in 1851.
Wildfire and smoke
167,427 acres burned in 18 large fires since 1984, equal to 23% of the land.
Largest
July 27, 2018
Ranch Fire, 426,721 acres
73,786 acres inside Colusa County.
Most recent
August 17, 2020
Hennessey Fire
314,015 acres in total.
Every large fire
| Hennessey | 2020 | 1,505 | 314,015 |
| Sand | 2019 | 263 | 2,472 |
| Ranch | 2018 | 73,786 | 426,721 |
| Rocky | 2015 | 10,683 | 96,061 |
| Sixteen Complex | 2012 | 18,191 | 18,177 |
| Walker Wye | 2012 | 4,504 | 5,844 |
| Sites Complex | 2012 | 3,324 | 3,605 |
| Mill | 2012 | 29,924 | 29,899 |
| Oasis | 2009 | 23 | 1,474 |
| Walker | 2008 | 7,087 | 12,429 |
| Forty | 2003 | 37 | 1,309 |
| Trough | 2001 | 7,338 | 25,249 |
| Sixteen | 1999 | 2,985 | 37,143 |
| Middle | 1998 | 4,397 | 6,378 |
| Fork | 1996 | 430 | 83,147 |
| Lightening Fire | 1992 | 1,277 | 1,278 |
| Unnamed | 1989 | 1,058 | 1,057 |
| Unnamed | 1988 | 607 | 3,308 |
- Large fires mapped by the Monitoring Trends in Burn Severity program since 1984: 1,000 acres or more in the West, 500 or more in the East. Prescribed burns are excluded. Acres here are the part of each perimeter inside this place.
Monitoring Trends in Burn Severity (USGS and U.S. Forest Service), 1984 to 2026.
Smoke overhead
Smokiest year
2021: 54 days
Heavy smoke on 41 days in 2020, the most of any year.
Last 10 years
21.7 days a year
Medium or heavy smoke, 2016 to 2025.
2025
5 days
Medium or heavy smoke. 10 so far in 2026.
- A smoke day is a date on which a smoke plume traced by NOAA Hazard Mapping System analysts from satellite imagery covered this place's point (the county's population centre or the city centre). Counts here are of medium or heavy smoke. Since 2018 analysts have often drawn light smoke as one area over most of the continent, so light-smoke counts are not comparable from year to year. The plumes show smoke anywhere in the air above, not air quality at the ground, and smoke hidden by cloud is missed.
NOAA Hazard Mapping System smoke analysis, 2011 to 2026, retrieved October 30, 2026.
Floods and flood insurance
160 federal flood insurance claims since 1983, with $3.0 million paid.
Most claims in one year
1998: 61 claims
$727,000 paid.
2nd most
1995: 41 claims
$952,000 paid.
3rd most
2017: 20 claims
$787,000 paid.
Claims by ZIP code
| 95932 | 101 | $1.7 million |
| 95955 | 27 | $457,000 |
| 95987 | 16 | $468,000 |
| 95912 | 8 | $128,000 |
Flood events since 1996
- Flood18
- Heavy Rain6
- Flash Flood1
1 death recorded in flood events since 1996.
This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026. NOAA Storm Events through 2026.
River crests
Most severe crest
March 1, 1940
Sacramento River at Colusa Weir, 70.60 ft
0.50 feet above the 70.1 ft flood stage; minor flooding by today’s categories.
| Mar 1, 1940 | Sacramento River at Colusa Weir | 70.60 | +0.50 |
| Mar 4, 1983 | Sacramento River at Colusa Weir | 68.96 | −1.14 |
| Jan 3, 1997 | Sacramento River at Colusa Bridge | 68.83 | −1.17 |
| Jan 3, 1997 | Sacramento River at Colusa Weir | 68.85 | −1.25 |
| Feb 26, 1958 | Sacramento River at Colusa Weir | 68.80 | −1.30 |
| Feb 21, 1958 | Sacramento River at Colusa Weir | 68.80 | −1.30 |
| Feb 7, 2025 | Sacramento River at Colusa Bridge | 68.55 | −1.45 |
| Mar 4, 1983 | Sacramento River at Colusa Bridge | 68.50 | −1.50 |
| Jan 7, 1965 | Sacramento River at Colusa Weir | 68.50 | −1.60 |
| Mar 1, 2019 | Sacramento River at Colusa Bridge | 68.33 | −1.67 |
| Feb 20, 2017 | Sacramento River at Colusa Bridge | 68.25 | −1.75 |
| Jan 24, 1943 | Sacramento River at Colusa Weir | 68.30 | −1.80 |
| Feb 6, 2025 | Sacramento River at Colusa Weir | 68.16 | −1.94 |
| Feb 26, 1958 | Sacramento River at Colusa Bridge | 68.00 | −2.00 |
| Feb 19, 1986 | Sacramento River at Colusa Bridge | 67.97 | −2.03 |
| Jan 2, 2006 | Sacramento River at Colusa Weir | 68.04 | −2.06 |
| Jan 11, 1995 | Sacramento River at Colusa Weir | 67.98 | −2.12 |
| Jan 2, 2006 | Sacramento River at Colusa Bridge | 67.72 | −2.28 |
| Feb 19, 1986 | Sacramento River at Colusa Weir | 67.80 | −2.30 |
| Jan 8, 1974 | Sacramento River at Colusa Bridge | 67.70 | −2.30 |
| Jan 25, 1970 | Sacramento River at Colusa Bridge | 67.60 | −2.40 |
| Jan 11, 1995 | Sacramento River at Colusa Bridge | 67.58 | −2.42 |
| Jan 10, 2017 | Sacramento River at Colusa Bridge | 67.55 | −2.45 |
| Jan 17, 1978 | Sacramento River at Colusa Weir | 67.60 | −2.50 |
| Jan 16, 2023 | Sacramento River at Colusa Bridge | 67.48 | −2.52 |
River gauges
| Sacramento River at Colusa Bridge | 70.0 | 68.83 ft | 0 |
| Sacramento River at Colusa Weir | 70.1 | 70.60 ft | 0 |
| Sacramento River at Moulton Weir | 83.8 | 79.83 ft | 0 |
- Crests are the highest and the recent crests the National Weather Service lists for each river gauge in the county that has a flood stage, not every flood. Flood categories use each gauge's current flood stages; crests from before levees, dams or channel changes may not be comparable. Crests measured on an old datum are left out of the rankings.
NOAA National Water Prediction Service gauge records, retrieved October 30, 2026.
Drought
In severe drought or worse for 107 of 1,581 months since 1895 (7%); the longest spell lasted 19 months.
107
Months in severe drought or worse since 1895
47
Months in extreme drought
7%
Share of all months, severe or worse
Lowest reading
July 2021
−7.75, extreme drought
Longest severe spell
19 months
February 1976 to August 1977.
Latest month
September 2026
−1.52, mild drought
Last severe month: August 2022.
- The Palmer Drought Severity Index is computed by NOAA each month from the county's average temperature and precipitation, relative to the county's own climate. Zero is normal; -3 or lower is severe drought and -4 or lower extreme drought. It describes the long-term balance of moisture, not water supply or crop losses.
NOAA NCEI nClimDiv county Palmer Drought Severity Index, 1895 to September 2026, issued October 6, 2026.
Earthquakes, volcanoes and landslides
153 earthquakes of magnitude 4 or more within 50 miles since 1900; the largest was magnitude 6.0 in 2014.
73
Magnitude 2.5+ inside the county since 1973
1,813
Magnitude 3+ within 50 miles since 1973
153
Magnitude 4+ within 50 miles since 1900
12
Magnitude 5+ within 50 miles since 1900
Largest within 50 miles
August 24, 2014
The 2014 South Napa, California Earthquake; 49.0 miles away, 6.9 miles deep.
Most recent, magnitude 3 or more
October 28, 2026
Magnitude 4.0
10 km N of Lake Pillsbury, CA; 12.1 miles away.
Every earthquake of magnitude 4 or more within 50 miles
- Earthquakes of magnitude 2.5 or more in the USGS Comprehensive Catalog since 1900. Within 50 miles means the epicentre lies within 50 miles of the county boundary (or inside the county).
- Small earthquakes were under-recorded before the modern seismic networks of the 1970s and are still missed in remote areas, so early decades read low. Magnitudes are as the catalogue reports them and mix scales (moment, local and body-wave).
USGS ANSS Comprehensive Earthquake Catalog, 1900 to present, retrieved October 30, 2026.
Volcanoes within 100 miles
| Clear Lake Volcanic Field | 16.0 | High |
| Lassen Volcanic Center | 79.1 | Very high |
- U.S. volcanoes within 100 miles, from the USGS Volcano Hazards Program. The threat category is the USGS 2018 National Volcanic Threat Assessment, which ranks volcanoes by how hazardous their past eruptions were and how many people and how much infrastructure lie near them. It is not a forecast of eruption.
USGS Volcano Hazards Program, retrieved October 30, 2026.
Mapped landslides
7
Landslides mapped, probable or better
1
With a recorded date
3
Source inventories
Mapped by CA GS (4), West Coast Slow Moving (Yuankun and others, 2021) (2), NASA (1).
- Landslides mapped in the USGS compilation of landslide inventories across the United States (version 3.0, 2025), rated probable or better. The compilation joins inventories made by federal and state agencies for different purposes and areas, so the number mapped in a county reflects how closely it has been surveyed as much as how often its slopes fail. An area with few records may simply not have been mapped. Deaths are as recorded in the inventories; a slide listed in two inventories is counted once.
USGS Landslide Inventories across the United States, version 3.0, retrieved October 27, 2026.
Severe weather and other events
35 events in the National Weather Service record, 34 of them since 1996.
1
Hail reports, 1 inch or larger
0
Hail, 2 inches or larger
1
Damaging gusts, 58 mph+
0
Winter weather events since 1996
0
Heat events since 1996
0
Cold events since 1996
Largest hail
February 2, 2019
1.25 inches
Strongest measured or estimated gust
April 24, 2016
58 mph
Costliest events since 1996
- Feb 17, 2017Flood$7.0 million
National Weather Service narrative
The town of Maxwell, CA started flooding near 2:00 am due to rain in the last day causing local creeks to rise. The Colusa County Sheriff's Office posted a voluntary evacuation notice at 8:30 am, with some people evacuated by boat. Interstate 5 near Maxwell was under a foot of water, causing travel disruption. |Water inundated most of the homes in a 9-block area in Maxwell. Damage to an elementary school, a sheriff's substation, roads and 78 homes could total $7 million, according to the Colusa County Office of Emergency Services.
- Jan 1, 2023Flood$1.0 million
National Weather Service narrative
Colusa County completed a preliminary estimate of damage to roads, road closures, debris removal, and high river levels of about $800,000 in damage. The Colusa Boat Landing had some damages to the private levee, with an estimate of about $200,000.
- Jan 1, 2006Flood$700,000
National Weather Service narrative
A series of warm winter storms brought heavy rain, mudslides, flooding, and high winds to Northern California. - Levee overtopping, breaching, and river flooding occurred along the Feather and Sacramento mainstem rivers as well as along numerous smaller rivers, creeks, and streams. Several urban areas had significant street flooding. The Sacramento weir was opened for the first time since 1997 with twenty gates opened. - Transportation throughout the area was difficult during the course of the storms as airports were closed due to the high winds and major road closures resulted from flooding and mudslides. Interstate 80...the main artery between Sacramento and the San Francisco…
- Mar 23, 2011Tornado$70,000
National Weather Service narrative
At approximately 3:00 pm an EF0 tornado touched down about a mile WSW of downtown Williams in Colusa County, near the intersection of Hwy 20 and Davis Road. The maximum wind speed of the tornado was estimated at 80 mph with a damage path of three quarters of a mile. The damage path was in an east-northeast direction. No injuries nor fatalities have been reported. The tornado damaged six homes, an out-building, two vehicles, and a home radio tower.
- Feb 14, 2019Flood$20,000
National Weather Service narrative
Caltrans reported that multiple vehicles were stuck in water on I-5.
- Storm Events records before 1996 cover only tornadoes, thunderstorm wind and hail. Damage figures are as reported by the National Weather Service at the time, not adjusted for inflation.
NOAA NCEI Storm Events Database, 1950 to 2026, issued October 26, 2026.
Weather records
From Colusa 2 Ssw, 3.9 miles from the county’s population centre, with records from 1948.
- All-time high
- 114°FSep 7, 2022
- All-time low
- 14°F2 times, most recently Dec 16, 2022
- Warmest night
- 82°FJun 22, 2017
- Coldest day
- 27°FDec 22, 1990
- Wettest day
- 3.56 inFeb 2, 1998
- Snowiest day
- 3.6 inJan 19, 1949
- Hottest year
- 2017mean 63.7°F
- Coldest year
- 2010mean 59.6°F
- Wettest year
- 198335.68 in
- Driest year
- 19764.20 in
- Snowiest season
- 3.6 in1948-49
56 of 58 winters had no measurable snow.
Station Colusa 2 Ssw (USC00041948), 50 ft elevation, 3.9 miles from the population centre. Daily records from 1948 to September 30, 2026; 87.2% of days in the last 30 years are complete. Records at a single station can differ from a city’s official threaded record, which may combine several stations.
NOAA NCEI Global Historical Climatology Network Daily.
Federal disaster declarations
19 since 1953. The most recent: Severe Winter Storms, Flooding, Landslides, and Mudslides, January 14, 2023.
| Jan 14, 2023 | Flood | DR-4683-CA |
| Jan 9, 2023 | Flood | EM-3591-CA |
| Mar 22, 2020 | Biological | DR-4482-CA |
| Mar 13, 2020 | Biological | EM-3428-CA |
| May 17, 2019 | Severe Storm | DR-4434-CA |
| May 1, 2019 | Severe Storm | DR-4431-CA |
| Apr 1, 2017 | Flood | DR-4308-CA |
| Feb 3, 2006 | Severe Storm | DR-1628-CA |
| Sep 13, 2005 | Hurricane | EM-3248-CA |
| Feb 9, 1998 | Severe Storm | DR-1203-CA |
| Jan 4, 1997 | Severe Storm | DR-1155-CA |
| Mar 12, 1995 | Severe Storm | DR-1046-CA |
| Jan 10, 1995 | Severe Storm | DR-1044-CA |
| Feb 11, 1991 | Freezing | DR-894-CA |
| Feb 21, 1986 | Flood | DR-758-CA |
| Feb 9, 1983 | Coastal Storm | DR-677-CA |
| Jan 20, 1977 | Drought | EM-3023-CA |
| Feb 16, 1970 | Flood | DR-283-CA |
| Dec 24, 1964 | Flood | DR-183-CA |
This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
OpenFEMA Disaster Declarations Summaries, retrieved October 30, 2026. Statewide declarations are not listed.
How this compares
Where Colusa County stands among 58 counties in California and 3,143 in the United States.
| Tornadoes since 1950 | 4 | 30 / 58 |
| Tornadoes rated F3/EF3 or stronger | 0 | — |
| Tropical cyclones within 50 mi | 0 | — |
| Hurricane-strength passes within 50 mi | 0 | — |
| Wildfire acres since 1984 | 167,427 | 36 / 58 |
| Flood insurance claims | 160 | 38 / 58 |
| Flood insurance paid | $3.0 million | 36 / 58 |
| Disaster declarations | 19 | 47 / 58 |
| Flood events since 1996 | 25 | 53 / 58 |
| Hail and wind events since 1996 | 2 | 58 / 58 |
| Winter storm events since 1996 | 0 | — |
| Reported damage since 1996 | $8.8 million | 48 / 58 |
| River crests at major flood stage | 0 | — |
| High tide flooding days a year, last 10 years | 0.0 | — |
| Months in severe drought since 1895 | 107 | 39 / 58 |
| Medium or heavy smoke days a year, last 10 years | 21.7 | 10 / 58 |
| Earthquakes M4+ within 50 mi since 1900 | 153 | 39 / 58 |
| Earthquakes M2.5+ in the county since 1973 | 73 | 44 / 58 |
Neighbouring counties
| Butte County | 18 | 0 |
| Glenn County | 11 | 0 |
| Lake County | 0 | 0 |
| Sutter County | 6 | 0 |
| Yolo County | 4 | 0 |
Sources and vintage
Every number on this page comes from these public records.
- Tornadoes NOAA Storm Prediction Center severe weather database, through 2025.
- Tropical cyclones NOAA National Hurricane Center HURDAT2 (Atlantic; Northeast and Central Pacific), through 2025.
- Wildfire USGS/USFS Monitoring Trends in Burn Severity, through 2026.
- Storm events NOAA NCEI Storm Events Database, through 2026.
- Flood insurance OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026.
- Declarations OpenFEMA Disaster Declarations Summaries v2, retrieved October 30, 2026.
- Weather records NOAA NCEI Global Historical Climatology Network Daily, station USC00041948.
- River crests NOAA National Weather Service, National Water Prediction Service river gauges, retrieved October 30, 2026.
- Drought NOAA NCEI nClimDiv county Palmer Drought Severity Index, through September 2026.
- Smoke NOAA NESDIS Hazard Mapping System smoke analysis, retrieved October 30, 2026.
- Volcanoes USGS Volcano Hazards Program, U.S. volcanoes and 2018 threat assessment.
- Landslides USGS Landslide Inventories across the United States, version 3.0 (2025).
- Earthquakes USGS ANSS Comprehensive Earthquake Catalog (ComCat), retrieved October 30, 2026.
Joins, thresholds and known limits are set out in the methodology. Found an error? Report it. Page built October 30, 2026.