Arcata climate — normals and trends
Arcata (United States) has a warm-summer mediterranean climate (Csb) under the Köppen-Geiger classification. Its mean annual temperature is 10.7 °C and it receives 1,374 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is August (15.2 °C on average) and the coldest is January (6.8 °C). Rainfall peaks in December.
Arcata averages 5 frost days, 0 hot days (≥ 30 °C) and 106 rainy days per year.
Arcata has warmed by +0.6 °C between 1940 and 2025, or +0.07 °C per decade. This trend is statistically significant.
The number of frost days there went from about 9 to 1 per year over the period.
The hottest day of the period reached 30.8 °C (on 28 September 2020) and the coldest -14.2 °C (on 21 December 1990).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
ArcataCalifornia
- coords
- 40.87°, -124.08°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
10.7°C
Average daily high
14.4°C
Average daily low
7.6°C
Annual rainfall
1,374mm
Sunshine / day
10.0h
Mean relative humidity
80%
Average peak wind
16.2km/h
Seasonal range
8.4°C
Frost days (< 0 °C)
5 d/yr
Hot days (≥ 30 °C)
0 d/yr
Rainy days (≥ 1 mm)
106 d/yr
Annual snowfall
39.4 cm
Average feels-like high
12.9 °C
Average feels-like low
5.3 °C
Average peak gust
35.7 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
16.9 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+0.6 °C
since 1940
+0.1 °C per decade · r² = 0.12 · p = 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
30.8 °C
28 September 2020
Coldest day
-14.2 °C
21 December 1990
Wettest day
128 mm
30 December 1954
Windiest day
45.3 km/h
12 October 1962
Strongest gust
121.3 km/h
14 December 2002
Hottest feels-like
32.2 °C
15 July 1972
Coldest feels-like
-19.4 °C
21 December 1990
Snowiest day
14.6 cm
17 January 1955
Sunniest day
14.8 h
16 June 1940
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 12.1 °C | +2.0 °C | 134 mm | -100 mm |
| Feb | 10.0 °C | -0.8 °C | 254 mm | +67 mm |
| Mar | 10.9 °C | -0.3 °C | 300 mm | +107 mm |
| Apr | 13.5 °C | +1.0 °C | 74 mm | -30 mm |
| May | 14.4 °C | -0.1 °C | 25 mm | -37 mm |
| Jun | 17.0 °C | +0.2 °C | 2 mm | -21 mm |
| Jul | 18.8 °C | -0.5 °C | 2 mm | -3 mm |
| Aug | 20.2 °C | +0.7 °C | 2 mm | -9 mm |
| Sep | 19.3 °C | +0.2 °C | 42 mm | +18 mm |
| Oct | 15.5 °C | -0.7 °C | 102 mm | +5 mm |
| Nov | 14.1 °C | +1.7 °C | 186 mm | -6 mm |
| Dec | 11.9 °C | +1.7 °C | 307 mm | +63 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Arcata?
Arcata has a warm-summer mediterranean climate (Köppen Csb). Over 1940-2025, the average annual temperature is 10.7 °C and it receives 1,374 mm of precipitation per year.
What is the hottest day ever recorded in Arcata?
The hottest day measured in Arcata between 1940 and 2025 was 28 September 2020, reaching 30.8 °C.
What is the coldest day in Arcata?
The coldest day measured in Arcata between 1940 and 2025 was 21 December 1990, at -14.2 °C.
Does it snow in Arcata?
Yes. Arcata gets on average 39.4 cm of snow per year and has around 5 frost days.
Has the climate of Arcata warmed?
Yes: Arcata warmed by +0.6 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Arcata?
The wettest day measured in Arcata between 1940 and 2025 was 30 December 1954, with 128 mm of rain in 24 hours.
What was the windiest day in Arcata?
The windiest day measured in Arcata between 1940 and 2025 was 12 October 1962, with winds reaching 45.3 km/h.
What is the warmest month in Arcata?
The warmest month in Arcata is August (15.2 °C on average); the coldest is January (6.8 °C).
How much does it rain in Arcata?
Arcata receives on average 1,374 mm of precipitation per year, spread over about 106 rainy days.
Is it sunny in Arcata?
Arcata gets on average 10.0 hours of sunshine per day, roughly 3,650 hours per year over 1940-2025.
What is the biggest single-day snowfall in Arcata?
The heaviest 24-hour snowfall measured in Arcata between 1940 and 2025 was 17 January 1955, with 14.6 cm.
Are there tropical nights in Arcata?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Arcata.
What was the most extreme apparent temperature in Arcata?
In Arcata, between 1940 and 2025, the highest apparent temperature reached 32.2 °C on 15 July 1972, and the lowest was -19.4 °C on 21 December 1990.
Compare Arcata with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Arcata