Rohnert Park, CA climate
Rohnert Park has mild winters and pleasant summers. A typical July afternoon reaches 82°, a January night drops to 38°, and snow is almost unheard of.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Rohnert Park feels like
Winter
Spring
Summer
Fall
Rohnert Park 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 | 58° | 38° | 6.1" | 0 | 12 | 0 | 45° – 52° |
| February | 62° | 40° | 6.2" | 0 | 11 | 0 | 46° – 56° |
| March | 65° | 41° | 4.2" | 0 | 10 | 0 | 48° – 59° |
| April | 69° | 43° | 2.0" | 0 | 6 | 0 | 51° – 59° |
| May | 74° | 47° | 1.1" | 0 | 4 | 0 | 55° – 65° |
| June | 80° | 50° | 0.3" | 0 | 1 | 0 | 61° – 68° |
| July | 82° | 51° | 0.0" | 0 | 0 | 0 | 64° – 70° |
| August | 83° | 51° | 0.1" | 0 | 0 | 0 | 64° – 71° |
| September | 82° | 50° | 0.1" | 0 | 1 | 0 | 63° – 70° |
| October | 76° | 47° | 1.5" | 0 | 4 | 0 | 59° – 66° |
| November | 65° | 41° | 3.4" | 0 | 8 | 0 | 47° – 57° |
| December | 57° | 38° | 6.5" | 0 | 12 | 0 | 44° – 52° |
| Year | 71° | 45° | 31.4" | 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 Rohnert Park
Rohnert Park gets 31 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 Rohnert Park
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Rohnert Park, 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 Rohnert Park 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 Rohnert Park averaged 1.4° warmer than the 1900s. The biggest change is in January (+2.2°). The shift is larger than in 64% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Rohnert Park’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 48° to 59°. July is the most reliable, staying within 6°.
Common questions about Rohnert Park’s climate
What is the coldest month in Rohnert Park?
December, with a typical high of 57° and a low of 38°.
What is the hottest month in Rohnert Park?
August, with a typical high of 83° and a low of 51°. About 21 days a year reach 90°.
How much snow does Rohnert Park get?
Almost none. A normal year brings 0.0 inches.
When is the first frost in Rohnert Park?
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 Rohnert Park?
December, with 6.5 inches of rain and melted snow. The year totals 31 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Rohnert Park 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.