Running in San Francisco
- Months in the band
- 12
- Longest run
- January, February, March, April, May, June, July, August, September, October, November and December
- Warmest month
- September, 17.6
- Band used
- 5 to 20
Of the twelve months measured over twenty years in San Francisco, 12 fall inside the 5 to 20 degree band used here for Running. The longest run of them is January, February, March, April, May, June, July, August, September, October, November and December.
The band sits low because running makes its own heat: a mean above 24 degrees turns an easy hour into a hard one even in dry air, and the same month is comfortable for walking.
The warmest month is September, at a mean of 17.6 degrees. The coldest is January, at 9.4.
Rain is heaviest in December, about 138 mm across the month, and lightest in July at 1 mm.
The figures are monthly means for San Francisco over 2001-2020, read from one satellite reanalysis cell. The 5 to 20 degree band is a stated convention rather than a measurement, and it is the only judgement on this page.
This page says when, not where. It names no route, trail, pool, gym or club, because the dataset that holds those is not built here. There is no water temperature, no gradient and no surface in this source either, so a comfortable month is about the air and nothing else.
Running in San Francisco
| Month | Mean temperature | Rain | In the band |
|---|---|---|---|
| January | 9.4 | 100 mm | yes |
| February | 10.3 | 102 mm | yes |
| March | 11.4 | 83 mm | yes |
| April | 12.2 | 42 mm | yes |
| May | 14 | 18 mm | yes |
| June | 16 | 6 mm | yes |
| July | 16.8 | 1 mm | yes |
| August | 17.3 | 1 mm | yes |
| September | 17.6 | 4 mm | yes |
| October | 15.9 | 30 mm | yes |
| November | 12.4 | 62 mm | yes |
| December | 9.6 | 138 mm | yes |
Questions
When is the best time for running in San Francisco?
The longest comfortable run is January, February, March, April, May, June, July, August, September, October, November and December, on the 5 to 20 degree band this page states. The table gives every month, so a different band can be read off it.
Does this list routes?
No. It says which months are comfortable and nothing about where to go. Routes, trails and pools need a dataset this programme has not been able to build, and inventing a route list would be worse than leaving it out.
Where do the temperatures come from?
From monthly climate normals published by NASA POWER, averaged over twenty years and read at one grid cell for the city. They are means for the whole day and month, not daytime highs.
Related pages
Sources
- NASA POWER, https://power.larc.nasa.gov/api/temporal/climatology/point (CC BY 4.0; 'There are no restrictions on the use, access, and/or download of data from the NASA POWER Project' (AWS Open Data Registry entry))