Vallejo, CA climate
Vallejo has warm winters and cool summers, with very little rain. A typical July afternoon reaches 75°, a January night drops to 43°, and snow is almost unheard of.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Vallejo feels like
Winter
Spring
Summer
Fall
Vallejo 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 | 57° | 43° | 4.4" | 0 | 11 | 0 | 46° – 55° |
| February | 61° | 45° | 4.1" | 0 | 11 | 0 | 48° – 57° |
| March | 64° | 47° | 3.3" | 0 | 10 | 0 | 50° – 61° |
| April | 67° | 48° | 1.5" | 0 | 7 | 0 | 53° – 61° |
| May | 70° | 52° | 0.7" | 0 | 3 | 0 | 56° – 66° |
| June | 75° | 55° | 0.2" | 0 | 1 | 0 | 62° – 67° |
| July | 75° | 56° | 0.0" | 0 | 0 | 0 | 63° – 69° |
| August | 76° | 56° | 0.0" | 0 | 1 | 0 | 63° – 71° |
| September | 76° | 56° | 0.1" | 0 | 1 | 0 | 62° – 70° |
| October | 72° | 53° | 1.0" | 0 | 3 | 0 | 60° – 68° |
| November | 64° | 47° | 2.3" | 0 | 7 | 0 | 49° – 60° |
| December | 57° | 42° | 4.0" | 0 | 11 | 0 | 46° – 55° |
| Year | 68° | 50° | 21.5" | 0.0" | 67 | 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 Vallejo
Vallejo gets 21 inches of rain and melted snow a year. January is the wettest month and July the driest. Rain or snow falls on about 67 days a year.
A year-round growing season
Heating and cooling a home in Vallejo
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Vallejo, 93% of that work is heating and 7% 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.
Vallejo and its neighbors
Vallejo borders 2 towns with climate data. January nights across them vary by 3.1°. Benicia has both the coldest January nights (40°) and the hottest July afternoons (84°). Vallejo’s January low is 43° and its July high 75°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Vallejo 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 Vallejo averaged 1.5° warmer than the 1900s. The biggest change is in January (+2.3°). The shift is larger than in 72% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Vallejo’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. November swings the most: between 1991 and 2020 its average temperature ranged from 49° to 60°. June is the most reliable, staying within 6°.
Common questions about Vallejo’s climate
What is the coldest month in Vallejo?
December, with a typical high of 57° and a low of 42°.
What is the hottest month in Vallejo?
August, with a typical high of 76° and a low of 56°. About 6 days a year reach 90°.
How much snow does Vallejo get?
Almost none. A normal year brings 0.0 inches.
When is the first frost in Vallejo?
Frost is uncommon. Only 27% of years see a night at 32° or below.
What is the rainiest month in Vallejo?
January, with 4.4 inches of rain and melted snow. The year totals 21 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Vallejo itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Berkeley, CA (16 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.