Colusa, California climate: Normal weather by month, frost dates and records
Colusa's normal year runs from 38°F December nights to 92°F July afternoons, with 17.2 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 16.4°C, December lows of 3°C, July highs of 34°C, 437 mm of precipitation a year.
- NOAA stationColusa (2 mi SSW)
- Station IDUSC00041948
- Location39.19°N 122.03°W
- Elevation50 ft (15 m)
- Population6,589
On October 23, the normal high in Colusa is 76°F and the normal low 46°F, and the chance of measurable rain or snow is 11%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Colusa.
- Jan 55° 38°
- Feb 60° 41°
- Mar 67° 44°
- Apr 73° 46°
- May 81° 53°
- Jun 88° 59°
- Jul 92° 60°
- Aug 92° 58°
- Sep 89° 54°
- Oct 79° 48°
- Nov 64° 42°
- Dec 55° 38°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Colusa each month?
July is the warmest month, with normal highs of 92°F; December the coldest, with normal lows of 38°F. The most precipitation falls in January (3.58 in), the least in July (0.01 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 55°F | 38°F | 46.4°F | 3.58 | 11 | <1 | 5 | 9 h 40 min |
| February | 60°F | 41°F | 50.7°F | 2.97 | 9 | <1 | 2 | 10 h 40 min |
| March | 67°F | 44°F | 55.1°F | 2.19 | 8 | <1 | 1 | 11 h 50 min |
| April | 73°F | 46°F | 59.7°F | 1.00 | 5 | 1 | <1 | 13 h 10 min |
| May | 81°F | 53°F | 67.3°F | 0.84 | 3 | 7 | <1 | 14 h 20 min |
| June | 88°F | 59°F | 73.4°F | 0.51 | 1 | 14 | <1 | 14 h 50 min |
| July | 92°F | 60°F | 76.2°F | 0.01 | <1 | 22 | <1 | 14 h 40 min |
| August | 92°F | 58°F | 74.9°F | 0.03 | <1 | 21 | <1 | 13 h 50 min |
| September | 89°F | 54°F | 71.8°F | 0.11 | 1 | 16 | <1 | 12 h 30 min |
| October | 79°F | 48°F | 63.5°F | 0.87 | 3 | 4 | <1 | 11 h 10 min |
| November | 64°F | 42°F | 53.0°F | 1.91 | 6 | <1 | 2 | 10 h |
| December | 55°F | 38°F | 46.1°F | 3.17 | 9 | <1 | 7 | 9 h 30 min |
| Year (annual) | 75°F | 48°F | 61.5°F | 17.19 | 55 | 85 | 17 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 13°C | 3°C | 8.0°C | 91 mm |
| February | 16°C | 5°C | 10.4°C | 75 mm |
| March | 19°C | 7°C | 12.8°C | 56 mm |
| April | 23°C | 8°C | 15.4°C | 25 mm |
| May | 27°C | 12°C | 19.6°C | 21 mm |
| June | 31°C | 15°C | 23.0°C | 13 mm |
| July | 34°C | 16°C | 24.6°C | 0 mm |
| August | 33°C | 15°C | 23.8°C | 1 mm |
| September | 32°C | 12°C | 22.1°C | 3 mm |
| October | 26°C | 9°C | 17.5°C | 22 mm |
| November | 18°C | 5°C | 11.7°C | 49 mm |
| December | 13°C | 3°C | 7.8°C | 81 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00041948; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Colusa?
Normal highs sit between 65°F and 85°F in March, April, May and October. Of those, October has the fewest days with rain (3).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00041948.
When is the last frost in Colusa?
In Colusa, the last spring frost (32°F) comes after February 14 in half of years and after March 31 in one year in ten; the first autumn frost comes before December 1 in half of years and before November 11 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- February 141 year in 10 after March 31; 9 in 10 after January 2
- First autumn frost, half of years before
- December 11 year in 10 before November 11; 9 in 10 before December 26
NOAA puts the median frost-free season at 293 days, and the season without a hard freeze (28°F) at 342 days.
A hard freeze (28°F) comes after January 8 in half of springs and before December 15 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Colusa in zone 9b in ZIP code 95932, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Colusa's NOAA station is in zone 9b: the coldest night of a typical year reaches 27°F (25 complete years).
Frost dates for every NOAA station in California · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00041948; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Colusa?
In a normal year in Colusa, 85 days a year reach 90°F (13 of them 100°F or more), 17 nights fall to 32°F or colder and 55 days bring measurable precipitation.
- Days at 90°F or more
- 85a normal year
- Days at 100°F or more
- 13a normal year
- Nights at 32°F or colder
- 17a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 55a normal year
The highest temperature in this station's record (since 1948) is 114°F, on September 7, 2022; the lowest is 14°F, on December 16, 2022.
The wettest calendar year on that record is 1998, with 30.83 in; the snowiest season is 1972–73, with 2.3 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00041948; records: ACIS (NOAA Regional Climate Centers), station USC00041948. Records use complete months only; a month missing more than three days is left out.
How sunny is Colusa?
Over a year 88% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Colusa, 5.2 kWh per square metre a day. July is the sunniest month (98%) and December the cloudiest (70%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 72% | 2.2 |
| February | 76% | 3.2 |
| March | 78% | 4.5 |
| April | 83% | 6.0 |
| May | 88% | 7.3 |
| June | 94% | 8.2 |
| July | 98% | 8.3 |
| August | 97% | 7.3 |
| September | 95% | 5.9 |
| October | 89% | 4.2 |
| November | 80% | 2.6 |
| December | 70% | 1.9 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Colusa need?
A normal year in Colusa brings 2,587 heating degree days, 52% fewer than the median U.S. place (5,373), and 1,329 cooling degree days, 46% more than the median (908). Five months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 4,582 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 577 | 0 |
| February | 402 | 0 |
| March | 307 | 2 |
| April | 179 | 22 |
| May | 56 | 126 |
| June | 7 | 261 |
| July | 0 | 346 |
| August | 0 | 307 |
| September | 9 | 212 |
| October | 101 | 53 |
| November | 362 | 1 |
| December | 586 | 0 |
| Year (annual) | 2,587 | 1,329 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00041948. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has Colusa been warmer than normal lately?
Over 50 complete years from 1949 to 2022, the station's annual mean temperature rose at a fitted 1.8°F per century (+0.10°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Colusa's climate compare?
Colusa is warmer than 111 of the other 218 places with their own NOAA record in California, and wetter than 118. Across the 7,247 U.S. stations with normals, its annual mean of 61.5°F is warmer than 78%.
In the Köppen classification computed from these normals, Colusa is Csa: temperate, dry-summer, hot summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Colusa share this climate record?
7 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Williams, CA5,598 people · 7 mi SW
- Arbuckle, CA3,209 people · 12 mi S
- Maxwell, CA1,174 people · 11 mi NW
- College City, CA575 people · 13 mi S
- Princeton, CA422 people · 15 mi N
- Meridian, CA386 people · 7 mi SE
- Grimes, CA371 people · 10 mi SE
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Colusa's climate
What is the coldest month in Colusa?
December, with a normal high of 55°F and a normal low of 38°F. The warmest is July (92°F by day, 60°F at night).
Does it snow in Colusa?
Rarely: NOAA's normal is no measurable snow a year.
What is the rainiest month in Colusa?
January, with 3.58 in of precipitation in a normal year; the driest is July with 0.01 in.
What plant hardiness zone is Colusa in?
The USDA's 2023 map puts Colusa in zone 9b in ZIP code 95932, the nearest ZIP area. By the same method at Colusa's NOAA station, the coldest night of a typical year reaches 27°F (25 years, 1991-2020): zone 9b.
How late can frost come in Colusa?
In half of years the last 32°F night comes after February 14; in one year in ten it comes after March 31. Waiting until March 31 leaves about a one-in-ten chance of a later frost.
Nearby and next
- California climateThe statewide normals and every place in the state
- Marysville, CA25 miles from this station, 62.0°F a year
- Willows, CA27 miles from this station, 63.7°F a year
- East Park Reservoir, CA29 miles from this station, 59.3°F a year
- Oroville, CA30 miles from this station, 63.2°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made