Glen Ellen, CA climate
Glen Ellen has warm winters and pleasant summers. A typical July afternoon reaches 82°, a January night drops to 41°, and snow is almost unheard of.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Glen Ellen feels like
Winter
Spring
Summer
Fall
Glen Ellen 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 | 55° | 41° | 7.6" | 0 | 12 | 0 | 45° – 52° |
| February | 58° | 40° | 7.4" | 0 | 11 | 0 | 44° – 54° |
| March | 61° | 41° | 5.4" | 0 | 10 | 0 | 46° – 57° |
| April | 65° | 43° | 2.5" | 0 | 6 | 0 | 49° – 58° |
| May | 71° | 47° | 1.5" | 0 | 4 | 0 | 54° – 64° |
| June | 78° | 51° | 0.3" | 0 | 1 | 0 | 61° – 67° |
| July | 82° | 55° | 0.0" | 0 | 0 | 0 | 66° – 71° |
| August | 83° | 55° | 0.0" | 0 | 0 | 0 | 66° – 73° |
| September | 81° | 55° | 0.1" | 0 | 1 | 0 | 65° – 72° |
| October | 74° | 51° | 2.0" | 0 | 4 | 0 | 60° – 68° |
| November | 62° | 44° | 4.2" | 0 | 8 | 0 | 47° – 57° |
| December | 55° | 40° | 8.4" | 0 | 12 | 0 | 44° – 52° |
| Year | 69° | 47° | 39.5" | 0.0" | 70 | 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 Glen Ellen
Glen Ellen gets 39 inches of rain and melted snow a year. December is the wettest month and July the driest. Rain or snow falls on about 70 days a year.
About 271 frost-free days a year
In half of years the last 32° night comes by February 28 and the first one by November 25. That leaves about 271 frost-free days for gardens, longer than 93% of U.S. towns.
Heating and cooling a home in Glen Ellen
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Glen Ellen, 90% of that work is heating and 10% 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 Glen Ellen 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 Glen Ellen averaged 1.5° warmer than the 1900s. The biggest change is in January (+2.3°). The shift is larger than in 67% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Glen Ellen’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. March swings the most: between 1991 and 2020 its average temperature ranged from 46° to 57°. July is the most reliable, staying within 6°.
Common questions about Glen Ellen’s climate
What is the coldest month in Glen Ellen?
December, with a typical high of 55° and a low of 40°.
What is the hottest month in Glen Ellen?
August, with a typical high of 83° and a low of 55°. About 21 days a year reach 90°.
How much snow does Glen Ellen get?
Almost none. A normal year brings 0.0 inches.
When is the first frost in Glen Ellen?
In half of years the first 32° night comes by November 25, and the last spring frost by February 28.
What is the rainiest month in Glen Ellen?
December, with 8.4 inches of rain and melted snow. The year totals 39 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Glen Ellen itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Petaluma Airport, CA (8 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.