| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 29.6° | 22.8° | 765.8mm | 25.4 | 60 |
| February | 29.8° | 23.2° | 543.7mm | 21.3 | 59 |
| March | 30.5° | 23.7° | 480.2mm | 22.5 | 56 |
| April | 31.4° | 23.9° | 301mm | 18.1 | 52 |
| May | 32.2° | 24.3° | 379.4mm | 21.2 | 49 |
| June | 32.5° | 24.2° | 255.8mm | 17.6 | 48 |
| July | 32.6° | 23.9° | 357.6mm | 19 | 48 |
| August | 33.1° | 23.9° | 263.8mm | 16 | 46 |
| September | 32.9° | 24° | 221.5mm | 15.8 | 46 |
| October | 32.3° | — | 210.1mm | 17 | 49 |
| November | 31.1° | 23.8° | 532mm | 22.8 | 54 |
| December | 30.6° | 23.5° | 581.6mm | 24.2 | 56 |
January in San Francisco averages a daily high of 29.6°C with nights around 22.8°C. Expect roughly 25.4 wet days totalling 765.8mm. Generally workable, with some weather to plan around.
February in San Francisco averages a daily high of 29.8°C with nights around 23.2°C. Expect roughly 21.3 wet days totalling 543.7mm. Generally workable, with some weather to plan around.
March in San Francisco averages a daily high of 30.5°C with nights around 23.7°C. Expect roughly 22.5 wet days totalling 480.2mm. Generally workable, with some weather to plan around.
April in San Francisco averages a daily high of 31.4°C with nights around 23.9°C. Expect roughly 18.1 wet days totalling 301mm. Demanding conditions — pack for it and plan indoor options.
May in San Francisco averages a daily high of 32.2°C with nights around 24.3°C. Expect roughly 21.2 wet days totalling 379.4mm. Demanding conditions — pack for it and plan indoor options.
June in San Francisco averages a daily high of 32.5°C with nights around 24.2°C. Expect roughly 17.6 wet days totalling 255.8mm. Demanding conditions — pack for it and plan indoor options.
July in San Francisco averages a daily high of 32.6°C with nights around 23.9°C. Expect roughly 19 wet days totalling 357.6mm. Demanding conditions — pack for it and plan indoor options.
August in San Francisco averages a daily high of 33.1°C with nights around 23.9°C. Expect roughly 16 wet days totalling 263.8mm. Demanding conditions — pack for it and plan indoor options.
September in San Francisco averages a daily high of 32.9°C with nights around 24°C. Expect roughly 15.8 wet days totalling 221.5mm. Demanding conditions — pack for it and plan indoor options.
October in San Francisco averages a daily high of 32.3°C. Expect roughly 17 wet days totalling 210.1mm. Demanding conditions — pack for it and plan indoor options.
November in San Francisco averages a daily high of 31.1°C with nights around 23.8°C. Expect roughly 22.8 wet days totalling 532mm. Demanding conditions — pack for it and plan indoor options.
December in San Francisco averages a daily high of 30.6°C with nights around 23.5°C. Expect roughly 24.2 wet days totalling 581.6mm. Generally workable, with some weather to plan around.
Each month scores out of 100. It starts at 100 and loses points for daytime highs outside a 20–27°C band, for wet days, and for nights below 2°C. Nothing else is weighted in — no crowd data, no prices, no opinion. San Francisco peaks at 60.
Based on 30 years of records, November–April scores highest for comfort in San Francisco, balancing daytime temperature against rainfall.
August is the warmest, averaging a daily high of 33.1°C.
January is the wettest, averaging 765.8mm of rain across roughly 25.4 wet days.
January is the coolest month, with average daily highs around 29.6°C.