Castella, CA climate
Castella has mild winters and warm summers, with plenty of rain. A typical July afternoon reaches 92°, a January night drops to 30°, and about 27 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Castella feels like
Winter
Spring
Summer
Fall
Castella weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 49° | 30° | 10.7" | 8.2" | 15 | 10 | 35° – 46° |
| February | 53° | 31° | 11.0" | 6.7" | 13 | 6 | 35° – 48° |
| March | 58° | 33° | 9.7" | 2.7" | 13 | 2 | 39° – 52° |
| April | 64° | 36° | 4.8" | 0.6" | 11 | 0 | 45° – 55° |
| May | 74° | 43° | 2.8" | 0 | 8 | 0 | 51° – 65° |
| June | 83° | 49° | 1.3" | 0 | 4 | 0 | 61° – 72° |
| July | 92° | 54° | 0.1" | 0 | 1 | 0 | 68° – 77° |
| August | 91° | 52° | 0.2" | 0 | 1 | 0 | 69° – 76° |
| September | 85° | 46° | 0.7" | 0 | 2 | 0 | 63° – 69° |
| October | 72° | 39° | 3.2" | 0 | 6 | 0 | 51° – 60° |
| November | 57° | 33° | 7.4" | 1.7" | 10 | 1 | 36° – 49° |
| December | 48° | 29° | 12.4" | 6.8" | 14 | 6 | 35° – 43° |
| Year | 69° | 39° | 64.3" | 26.7" | 98 | 26 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in Castella
Castella gets 64 inches of rain and melted snow a year. December is the wettest month and July the driest. Rain or snow falls on about 98 days a year. Snow covers the ground about 26 days of the year.
About 185 frost-free days a year
In half of years the last 32° night comes by April 23 and the first one by October 27. That leaves about 185 frost-free days for gardens, longer than 58% of U.S. towns.
Heating and cooling a home in Castella
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Castella, 89% of that work is heating and 11% is cooling, so the furnace matters far more than the air conditioner.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
How Castella compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Castella averaged 1.2° warmer than the 1900s. The biggest change is in September (+2.3°). The shift is smaller than in 53% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Castella’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. May swings the most: between 1991 and 2020 its average temperature ranged from 51° to 65°. September is the most reliable, staying within 7°.
Common questions about Castella’s climate
What is the coldest month in Castella?
December, with a typical high of 48° and a low of 29°.
What is the hottest month in Castella?
July, with a typical high of 92° and a low of 54°. About 59 days a year reach 90°.
How much snow does Castella get?
About 27 inches in a normal winter, most of it in January.
When is the first frost in Castella?
In half of years the first 32° night comes by October 27, and the last spring frost by April 23.
What is the rainiest month in Castella?
December, with 12.4 inches of rain and melted snow. The year totals 64 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Castella itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Dunsmuir Trtmt Pl, CA (1 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.