Alta Sierra, CA climate
Alta Sierra has mild winters and warm summers, with plenty of rain. A typical July afternoon reaches 91°, a January night drops to 36°, and about 7 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Alta Sierra feels like
Winter
Spring
Summer
Fall
Alta Sierra 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 | 54° | 36° | 8.5" | 0.9" | 11 | 0 | 41° – 52° |
| February | 56° | 38° | 8.3" | 2.6" | 12 | 0 | 40° – 54° |
| March | 60° | 40° | 7.4" | 1.2" | 11 | 0 | 42° – 57° |
| April | 65° | 42° | 4.0" | 0.6" | 8 | 0 | 47° – 58° |
| May | 74° | 49° | 2.3" | 0 | 6 | 0 | 52° – 69° |
| June | 83° | 56° | 0.7" | 0 | 2 | 0 | 64° – 74° |
| July | 91° | 62° | 0.0" | 0 | 0 | 0 | 72° – 80° |
| August | 90° | 61° | 0.1" | 0 | 1 | 0 | 72° – 80° |
| September | 85° | 57° | 0.4" | 0 | 1 | 0 | 67° – 75° |
| October | 74° | 49° | 2.4" | 0 | 4 | 0 | 57° – 68° |
| November | 60° | 41° | 5.1" | 0.4" | 9 | 0 | 43° – 57° |
| December | 53° | 36° | 9.2" | 1.5" | 11 | 0 | 41° – 49° |
| Year | 70° | 47° | 48.3" | 7.2" | 76 | 1 |
“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 Alta Sierra
Alta Sierra gets 48 inches of rain and melted snow a year. December is the wettest month and July the driest. Rain or snow falls on about 76 days a year.
About 233 frost-free days a year
In half of years the last 32° night comes by April 3 and the first one by November 24. That leaves about 233 frost-free days for gardens, longer than 87% of U.S. towns.
Heating and cooling a home in Alta Sierra
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Alta Sierra, 72% of that work is heating and 28% is cooling.
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 Alta Sierra 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 Alta Sierra averaged 0.7° warmer than the 1900s. The biggest change is in September (+1.9°). The shift is smaller than in 89% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Alta Sierra’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 52° to 69°. August is the most reliable, staying within 7°.
Common questions about Alta Sierra’s climate
What is the coldest month in Alta Sierra?
December, with a typical high of 53° and a low of 36°.
What is the hottest month in Alta Sierra?
July, with a typical high of 91° and a low of 62°. About 66 days a year reach 90°.
How much snow does Alta Sierra get?
About 7 inches in a normal winter, most of it in February.
When is the first frost in Alta Sierra?
In half of years the first 32° night comes by November 24, and the last spring frost by April 3.
What is the rainiest month in Alta Sierra?
December, with 9.2 inches of rain and melted snow. The year totals 48 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Alta Sierra itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Colfax, CA (6 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.