San Francisco Temperatures: Averages by Month
The numbers here tell you how hot and cold the weather usually is in San Francisco, California during each month of the year.
The average high and low temperatures are listed below monthly and annually for San Francisco, in both degrees Fahrenheit and Celsius.
Maximums and minimums are only part of the temperature picture. To fill in the rest, there's information on how many days a month get above or below a given temperature.
To find out how often it rises over 60, 70 or 80 °F each month in San Francisco, scroll down farther. There are also counts of nights with warm temperatures and days with cold weather.
The weather data were recorded in downtown San Francisco near the corner of Buchanan and Hermann Streets. The first set of high and low temperatures are averages for 2010 to 2019. Everything else here is based on 1991 to 2020 weather.
| High °F | Low °F | High °C | Low °C | |
|---|---|---|---|---|
| 58 | 47 | January | 14 | 8 |
| 60 | 48 | February | 16 | 9 |
| 62 | 49 | March | 17 | 9 |
| 63 | 50 | April | 17 | 10 |
| 64 | 51 | May | 18 | 11 |
| 67 | 53 | June | 19 | 12 |
| 66 | 54 | July | 19 | 12 |
| 68 | 56 | August | 20 | 13 |
| 70 | 56 | September | 21 | 13 |
| 70 | 54 | October | 21 | 12 |
| 64 | 51 | November | 18 | 10 |
| 58 | 47 | December | 14 | 8 |
| 64 | 51 | Year | 18 | 11 |
| High °F | Low °F | High °C | Low °C | |
|---|---|---|---|---|
| 57 | 46 | January | 14 | 8 |
| 60 | 48 | February | 16 | 9 |
| 62 | 49 | March | 17 | 9 |
| 63 | 49 | April | 17 | 10 |
| 64 | 51 | May | 18 | 11 |
| 66 | 53 | June | 19 | 12 |
| 67 | 54 | July | 19 | 12 |
| 68 | 55 | August | 20 | 13 |
| 70 | 55 | September | 21 | 13 |
| 69 | 54 | October | 21 | 12 |
| 63 | 50 | November | 17 | 10 |
| 57 | 46 | December | 14 | 8 |
| 64 | 51 | Year | 18 | 10 |
Days of Hot Weather in San Francisco
San Francisco averages just three days a year when the temperature reaches 90 degrees Fahrenheit, and even fewer over 100 (38 °C). No matter how warm the day, at night the temperature always cools to less than 70 degrees.
The city's hottest days usually occur in September and October. But 80-degree weather can appear any month from February to November.
| 60 °F 16 °C |
70 °F 21 °C |
80 °F 27 °C | |
|---|---|---|---|
| January | 12 | 1 | 0 |
| February | 15 | 3 | 0 |
| March | 20 | 5 | 1 |
| April | 21 | 5 | 1 |
| May | 26 | 5 | 1 |
| June | 28 | 8 | 2 |
| July | 30 | 7 | 1 |
| August | 31 | 10 | 2 |
| September | 30 | 14 | 5 |
| October | 30 | 14 | 5 |
| November | 24 | 6 | 1 |
| December | 13 | 0 | 0 |
| Year | 279 | 77 | 18 |
| 50 °F 10 °C |
60 °F 16 °C | |
|---|---|---|
| January | 6 | 0 |
| February | 8 | 0 |
| March | 11 | 0 |
| April | 12 | 0 |
| May | 20 | 0 |
| June | 27 | 1 |
| July | 31 | 1 |
| August | 31 | 1 |
| September | 30 | 2 |
| October | 28 | 2 |
| November | 16 | 0 |
| December | 6 | 0 |
| Year | 224 | 7 |
How Often San Francisco Has Cold Temperatures
It never gets really cold in San Franciso. All but two days a year on average have highs of at least 50 degrees.
Nighttime lows of 40 °F (4 °C) or less typically happen only four times annually. Freezing temperatures are not at all normal for the city.
References
Jay Lawrimore, Ron Ray, Scott Applequist, Bryant Korzeniewski, Matthew Menne. 2016. Global Summary of the Month and Year, Version 1.0. NOAA National Centers for Environmental Information.
NOAA National Centers for Environmental Information (NCEI). Climate Normals.