San Francisco has cold, snowy winters and pleasant summers
A typical July afternoon reaches 83°, a January night drops to 6°, and about 40 inches of snow falls in a normal winter.
A year in San Francisco at a glance
Each month’s typical high and low, and what it brings.
What stands out about San Francisco’s climate
Read from where San Francisco sits among Minnesota’s towns. The page puts what stands out first.
About 153 frost-free days a year
In half of years the last 32° night comes by May 2 and the first by October 5.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
40 inches of snow, 32 of rain and melt
June is the wettest month and January the driest. Rain or snow falls on about 88 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
What a year in San Francisco feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
Living with San Francisco’s climate
What the numbers mean for a garden, a driveway, a furnace and a free afternoon.
153 frost-free days. The last frost comes by May 2 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 5.
About 40" a winter over 9 days with an inch or more, most in December. Snow covers the ground about 71 days a year.
Months averaging under 55° run from October through April. Heating is 94% of the year’s heating-and-cooling load.
About 6 days a year reach 90°, and July afternoons average 83°.
The nicest months are May, June, July, August and September. 2.6 miles of trails are waiting.
Parks & trails →Normals are averages. Ice storms, nor’easters, floods and heat waves are on the natural hazards page.
Natural hazards →San Francisco and its neighbors
St. Lawrence has the coldest January nights next door (6°) and St. Lawrence the hottest July afternoons (83°). Tap a town to see its climate.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in San Francisco averaged 1.3° warmer than the 1900s. The biggest change is in December (+3.1°).
A bigger shift than in 54% of U.S. towns.
Change by month
How San Francisco compares
Against every U.S. town on TownTapestry, each counted once, with its place in Minnesota.
San Francisco 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 | 23° | 6° | 0.8" | 6.4" | 5 | 24 | 3° – 28° |
| February | 28° | 10° | 0.9" | 10.2" | 4 | 17 | 8° – 31° |
| March | 41° | 23° | 1.7" | 5.2" | 6 | 11 | 24° – 48° |
| April | 57° | 36° | 3.0" | 3.6" | 8 | 1 | 35° – 55° |
| May | 69° | 48° | 4.3" | 0 | 11 | 0 | 54° – 66° |
| June | 79° | 58° | 4.9" | 0 | 10 | 0 | 64° – 72° |
| July | 83° | 62° | 4.2" | 0 | 10 | 0 | 65° – 78° |
| August | 80° | 60° | 4.3" | 0 | 9 | 0 | 65° – 75° |
| September | 73° | 52° | 3.3" | 0 | 8 | 0 | 55° – 67° |
| October | 59° | 39° | 2.5" | 0.4" | 7 | 0 | 41° – 53° |
| November | 42° | 26° | 1.6" | 3.0" | 5 | 2 | 24° – 45° |
| December | 29° | 13° | 1.1" | 11.0" | 5 | 15 | 6° – 29° |
| Year | 55° | 36° | 32.4" | 39.8" | 88 | 71 |
Heating and cooling a home in San Francisco
94% of the work is heating, so the furnace matters far more than the air conditioner.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. Source: NOAA station normals.
How much a month can swing
A normal is an average. January swings the most: from 1991 to 2020 its average ranged from 3° to 28°. June is the most reliable, staying within 8°.
Common questions about San Francisco’s climate
What is the coldest month in San Francisco?
January, with a typical high of 23° and a low of 6°.
What is the hottest month in San Francisco?
July, with a typical high of 83° and a low of 62°. About 6 days a year reach 90°.
How much snow does San Francisco get?
About 40 inches in a normal winter, most of it in December.
When is the first frost in San Francisco?
In half of years the first 32° night comes by October 5, and the last spring frost by May 2.
What is the rainiest month in San Francisco?
June, with 4.9 inches of rain and melted snow. The year totals 32 inches.
Neighbors talk weather
Gardens, snow, and the best days of the year in San Francisco.
Your answer becomes a post in Town Square.
Temperatures and rainfall come from NOAA’s gridded climate normals for San Francisco itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Jordan 1ssw, MN (5 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000. Today’s forecast: National Weather Service.