Plymouth, CA climate
Plymouth has mild winters and hot summers. A typical July afternoon reaches 95°, a January night drops to 38°, and snow is almost unheard of.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Plymouth feels like
Winter
Spring
Summer
Fall
Plymouth 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 | 56° | 38° | 5.5" | 0 | 11 | 0 | 43° – 54° |
| February | 60° | 40° | 5.1" | 0.1" | 11 | 0 | 43° – 56° |
| March | 64° | 42° | 5.1" | 0.1" | 10 | 0 | 45° – 60° |
| April | 69° | 44° | 2.5" | 0 | 7 | 0 | 51° – 61° |
| May | 78° | 50° | 1.7" | 0 | 5 | 0 | 55° – 73° |
| June | 88° | 56° | 0.2" | 0 | 1 | 0 | 65° – 78° |
| July | 95° | 61° | 0.0" | 0 | 0 | 0 | 73° – 83° |
| August | 94° | 60° | 0.0" | 0 | 0 | 0 | 73° – 81° |
| September | 89° | 56° | 0.2" | 0 | 1 | 0 | 68° – 77° |
| October | 78° | 50° | 1.3" | 0 | 3 | 0 | 60° – 71° |
| November | 64° | 42° | 3.0" | 0.1" | 7 | 0 | 45° – 59° |
| December | 56° | 37° | 5.1" | 0 | 11 | 0 | 42° – 51° |
| Year | 74° | 48° | 29.7" | 0.3" | 69 | 0 |
“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 Plymouth
Plymouth gets 30 inches of rain and melted snow a year. January is the wettest month and July the driest. Rain or snow falls on about 69 days a year.
About 285 frost-free days a year
In half of years the last 32° night comes by March 4 and the first one by December 11. That leaves about 285 frost-free days for gardens, longer than 94% of U.S. towns.
Heating and cooling a home in Plymouth
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Plymouth, 67% of that work is heating and 33% 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 Plymouth 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 Plymouth averaged 1.0° warmer than the 1900s. The biggest change is in September (+1.7°). The shift is smaller than in 72% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Plymouth’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 55° to 73°. December is the most reliable, staying within 8°.
Common questions about Plymouth’s climate
What is the coldest month in Plymouth?
December, with a typical high of 56° and a low of 37°.
What is the hottest month in Plymouth?
July, with a typical high of 95° and a low of 61°. About 75 days a year reach 90°.
How much snow does Plymouth get?
Almost none. A normal year brings 0.3 inches.
When is the first frost in Plymouth?
In half of years the first 32° night comes by December 11, and the last spring frost by March 4.
What is the rainiest month in Plymouth?
January, with 5.5 inches of rain and melted snow. The year totals 30 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Plymouth itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Fiddletown Dexter Rch, CA (10 mi, snow) and Sutter Hill Cdf, CA (7 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.