AI-generatedSan Francisco at a glance
- Best time
- Apr – Oct
- Warmest month
- Sep · 23°
- Warmest sea
- Sep · 14.6°
- Sunshine a year
- 2,900 h
- Rain a year
- 470 mm
- Climate
- Maritime
- Time zone
- UTC−8 / UTC−7
- Elevation
- 16 m
Climate in San Francisco
San Francisco has a maritime climate with moderate summers and cool, often grey winters. September is the warmest month with average highs of 23 °C, while December is the coolest at 14 °C. With around 2,900 hours of sunshine a year, San Francisco is sunny; June is the sunniest month with 10.9 hours a day.
Holiday weather through the year
Weather in October
Holiday weather in October
Excellent
Best time to visit: April – October
A typical day in October
- Morning, 08:00: about 13°
- Midday, 13:00: about 20°
- Afternoon, 16:00: about 21°
- Evening, 20:00: about 17°
- Night, 23:00: about 15°
07:1718:34
Cool evenings: pack a jumper or a jacket.
Estimated from the average high and low: coolest around sunrise, warmest in mid-afternoon.
What is the weather like in San Francisco in October?
In October, San Francisco is warm: daytime highs average 21 °C, and nights cool down to about 12 °C. The sea averages 13.9 °C – swimming is only for the hardy. The sun shines for around 8 hours a day. Rain is rare: about 3 days bring 23 mm in total. All in all, October is an excellent month for a holiday in San Francisco.
More details for October
- Daylight
- 11 h 17 min07:17 – 18:34
- UV index
- 5 · moderateclear sky, noon (estimate)All months
- Muggy days
- 0 daysdew point 18 °C or more
- Wind
- 14 km/haverage daily peak
- Cloud cover
- 39 %on average
- Hot days
- 1 day30 °C or more
- Time zone
- UTC−7America/Los_Angeles
How the score comes together
- Temperatureweight 50 %100 %
- Sunshineweight 20 %77 %
- Few rainy daysweight 30 %100 %
Each factor is rated from 0 to 100 % and weighted for the travel style “City break”.
What to pack in October
- Sunscreen
- A jumper for the evenings
Sea temperature in San Francisco
Monthly sea surface temperature with the range of cooler and warmer years.
8 in 10 years: 12.8 – 15.4 °C
Swimming season: Never above 20 °C
- cold
- fresh
- refreshing
- pleasant
- warm
- very warm
The sea temperature in San Francisco ranges from 11.4 °C in April to 14.6 °C in September. Even at its warmest the sea stays below 20 °C, so swimming is bracing at best.
The sea temperature varies from year to year: in September, eight out of ten years were between 13.5 and 16.0 °C.
| Month | Average | Cool year | Warm year | Feels |
|---|---|---|---|---|
| JanuaryJan | 11.7° | 10.6° | 12.7° | cold |
| FebruaryFeb | 11.8° | 10.8° | 13.0° | cold |
| MarchMar | 11.8° | 10.5° | 13.3° | cold |
| AprilApr | 11.4° | 10.1° | 12.5° | cold |
| MayMay | 11.7° | 10.9° | 12.8° | cold |
| JuneJun | 12.3° | 11.0° | 13.9° | cold |
| JulyJul | 13.6° | 12.6° | 14.4° | cold |
| AugustAug | 14.5° | 13.2° | 15.7° | cold |
| SeptemberSep | 14.6° | 13.5° | 16.0° | cold |
| OctoberOct | 13.9° | 12.8° | 15.4° | cold |
| NovemberNov | 13.0° | 12.0° | 14.4° | cold |
| DecemberDec | 12.1° | 11.0° | 13.3° | cold |
Sunshine hours in San Francisco
Average hours of bright sunshine per day, next to the length of the day. Tap a month to select it.
In October, the sun shines for about 7.6 of 11.3 hours of daylight in San Francisco, 67 % of the day.
Sunshine hours: estimated from radiation data (ERA5, 1996–2025) and calibrated against measured station values; no weather station is close enough here. Daylight is the time from sunrise to sunset on the 15th of the month.
UV index in San Francisco
How strong the sun is at noon, month by month, and how quickly unprotected skin burns.
- Clear-sky UV in October
- 5 · moderateAround midday seek shade; use sunscreen, a hat and sunglasses.
The sun is strongest in June (UV 10).
Minutes until sunburn in October
- Very fair skin
- about 30 min
- Fair skin
- about 35 min
- Light brown skin
- about 50 min
- Olive skin
- about 65 min
Rough guide for unprotected skin at noon under a clear sky; clouds lengthen it, water, sand and snow shorten it. Sunscreen extends the time only partly.
Monthly values: clear-sky noon estimate from the sun's angle, ozone and altitude. UV today: Open-Meteo forecast.
Rain in San Francisco: rainy days and rainfall
A rainy day is a day with at least 1 mm of rain or snow; the amount is what falls in the whole month. Tap a month to select it.
In October, San Francisco has about 3 rainy days with 23 mm of rain in total.
Climate through the year
Long-term monthly averages. Tap a month to see its details.
Temperatures through the year
Average daytime high, night-time low and sea temperature per month.
| Month | Score | Day | Night | Sea | Sun | Rain days | Rain mm |
|---|---|---|---|---|---|---|---|
| JanuaryJan | 54 | 14° | 6° | 11.7° | 4.9 h | 9 | 89 |
| FebruaryFeb | 62 | 15° | 7° | 11.8° | 5.9 h | 9 | 93 |
| MarchMar | 72 | 16° | 8° | 11.8° | 6.9 h | 9 | 67 |
| AprilApr | 94 | 17° | 9° | 11.4° | 8.8 h | 5 | 33 |
| MayMay | 100 | 19° | 10° | 11.7° | 10.0 h | 3 | 16 |
| JuneJun | 100 | 21° | 12° | 12.3° | 10.9 h | 1 | 3 |
| JulyJul | 100 | 22° | 13° | 13.6° | 10.5 h | 0 | 0 |
| AugustAug | 100 | 22° | 13° | 14.5° | 10.0 h | 0 | 1 |
| SeptemberSep | 100 | 23° | 13° | 14.6° | 9.1 h | 1 | 2 |
| OctoberOct | 95 | 21° | 12° | 13.9° | 7.6 h | 3 | 23 |
| NovemberNov | 78 | 17° | 9° | 13.0° | 5.9 h | 6 | 50 |
| DecemberDec | 52 | 14° | 7° | 12.1° | 4.8 h | 10 | 93 |
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0)
37.77° N, 122.42° W · 16 m · America/Los_Angeles
Best time to visit San Francisco
The best time to visit San Francisco is from April to October. The sea stays too cool for a classic beach holiday: even in September it only reaches 14.6 °C. For sightseeing, day trips and hiking, conditions are most comfortable from March to November. The wettest month is February with 93 mm of precipitation.
San Francisco through the seasons
How the weather changes over the seasons, with averages for each.
San Francisco in spring
Mar – May
Excellent
- 16–19 °C by day
- Sea 12 °C
- 9 h of sun a day
- 16 rainy days in all
San Francisco in summer
Jun – Aug
Excellent
- 21–22 °C by day
- Sea 14 °C
- 11 h of sun a day
- 1 rainy days in all
San Francisco in autumn
Sep – Nov
Excellent
- 17–23 °C by day
- Sea 14 °C
- 8 h of sun a day
- 10 rainy days in all
San Francisco in winter
Dec – Feb
Fair
- 14–15 °C by day
- Sea 12 °C
- 5 h of sun a day
- 28 rainy days in all
Find your perfect month
Tell us what you like and we rate every month in San Francisco for you.
Your best months: July – September
Based on the climate averages; tap a month to see its details.
Which month for what?
Beach & swimming
No month
Sea from 21 °C, warm and mostly dry
Sightseeing & hiking
Mar – Nov
15–28 °C and not too much rain
San Francisco month by month
The typical weather for every month at a glance.
54January14° · Sea 12° · 5 h
In January, San Francisco is cool: daytime highs average 14 °C, and nights cool down to about 6 °C. The sea averages 11.7 °C – swimming is only for the hardy. Expect around 5 hours of sunshine a day. Rain falls on about 9 days, adding up to 89 mm. All in all, January is a so-so month for a holiday in San Francisco.
San Francisco in January62February15° · Sea 12° · 6 h
In February, San Francisco is cool: daytime highs average 15 °C, and nights cool down to about 7 °C. The sea averages 11.8 °C – swimming is only for the hardy. Expect around 6 hours of sunshine a day. Rain falls on about 9 days, adding up to 93 mm. All in all, February is a good month for a holiday in San Francisco.
San Francisco in February72March16° · Sea 12° · 7 h
In March, San Francisco is cool: daytime highs average 16 °C, and nights cool down to about 8 °C. The sea averages 11.8 °C – swimming is only for the hardy. The sun shines for around 7 hours a day. Rain falls on about 9 days, adding up to 67 mm. All in all, March is a good month for a holiday in San Francisco.
San Francisco in March94April17° · Sea 11° · 9 h
In April, San Francisco is mild: daytime highs average 17 °C, and nights cool down to about 9 °C. The sea averages 11.4 °C – swimming is only for the hardy. The sun shines for around 9 hours a day. Rain is rare: about 5 days bring 33 mm in total. All in all, April is an excellent month for a holiday in San Francisco.
San Francisco in April100May19° · Sea 12° · 10 h
In May, San Francisco is mild: daytime highs average 19 °C, and nights cool down to about 10 °C. The sea averages 11.7 °C – swimming is only for the hardy. With around 10 hours of sunshine a day, there is plenty of sun. Rain is rare: about 3 days bring 16 mm in total. All in all, May is an excellent month for a holiday in San Francisco.
San Francisco in May100June21° · Sea 12° · 11 h
In June, San Francisco is warm: daytime highs average 21 °C, and nights cool down to about 12 °C. The sea averages 12.3 °C – swimming is only for the hardy. With around 11 hours of sunshine a day, there is plenty of sun. It hardly ever rains. All in all, June is an excellent month for a holiday in San Francisco.
San Francisco in June100July22° · Sea 14° · 11 h
In July, San Francisco is warm: daytime highs average 22 °C, and nights cool down to about 13 °C. The sea averages 13.6 °C – swimming is only for the hardy. With around 11 hours of sunshine a day, there is plenty of sun. It hardly ever rains. All in all, July is an excellent month for a holiday in San Francisco.
San Francisco in July100August22° · Sea 15° · 10 h
In August, San Francisco is warm: daytime highs average 22 °C, and nights cool down to about 13 °C. The sea averages 14.5 °C – swimming is only for the hardy. With around 10 hours of sunshine a day, there is plenty of sun. It hardly ever rains. All in all, August is an excellent month for a holiday in San Francisco.
San Francisco in August100September23° · Sea 15° · 9 h
In September, San Francisco is warm: daytime highs average 23 °C, and nights cool down to about 13 °C. The sea averages 14.6 °C – swimming is only for the hardy. With around 9 hours of sunshine a day, there is plenty of sun. It hardly ever rains. All in all, September is an excellent month for a holiday in San Francisco.
San Francisco in September95October21° · Sea 14° · 8 h
In October, San Francisco is warm: daytime highs average 21 °C, and nights cool down to about 12 °C. The sea averages 13.9 °C – swimming is only for the hardy. The sun shines for around 8 hours a day. Rain is rare: about 3 days bring 23 mm in total. All in all, October is an excellent month for a holiday in San Francisco.
San Francisco in October78November17° · Sea 13° · 6 h
In November, San Francisco is mild: daytime highs average 17 °C, and nights cool down to about 9 °C. The sea averages 13.0 °C – swimming is only for the hardy. Expect around 6 hours of sunshine a day. Rain falls on about 6 days, adding up to 50 mm. All in all, November is a good month for a holiday in San Francisco.
San Francisco in November52December14° · Sea 12° · 5 h
In December, San Francisco is cool: daytime highs average 14 °C, and nights cool down to about 7 °C. The sea averages 12.1 °C – swimming is only for the hardy. Expect around 5 hours of sunshine a day. Rain is frequent, with about 10 rainy days and 93 mm in total. All in all, December is a so-so month for a holiday in San Francisco.
San Francisco in DecemberSan Francisco compared
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San Francisco vs. Los Angeles
In October the holiday weather in San Francisco and Los Angeles is about equally good (score 95 vs. 98). During the day Los Angeles is 5 °C warmer than San Francisco. The sea in Los Angeles is 5 °C warmer.
| in October | San Francisco | Los Angeles |
|---|---|---|
| Holiday score | 95 | 98 |
| Daytime high | 21° | 26° |
| Sea | 14° | 19° |
| Sunshine | 8 h | 8 h |
| Rainy days | 3 | 2 |
| Best time | Apr – Oct | Sep – Jul |
Through the year
USA in October: the best places
In October, San Francisco ranks 3 of 10 destinations in this country.
- Las Vegas26°99
- 2Los Angeles26°19°98
- 3San FranciscoThis page21°14°95
- 4Kihei29°27°95
- 5Honolulu27°27°92
- 6Key West27°28°81
- 7New York18°18°77
- 8Miami Beach28°28°77
Planning a trip to San Francisco
Weather for your travel dates
Pick your arrival and length of stay, and we sum up the weather to expect.
Getting there
Flying from
- Nonstop flight
- about 10 h 50 min
- Distance
- 8,600 km
- Time zone
- UTC−7
Estimated from the straight-line distance: 30 minutes for take-off and landing plus 830 km/h cruising speed.
Frequently asked questions about San Francisco
When is the best time to visit San Francisco?
The best time to visit San Francisco is from April to October. That is when the holiday weather score, which combines temperature, sea, sunshine and rain, is highest.
How warm is the sea in San Francisco?
The sea temperature in San Francisco ranges from 11.4 °C in April to 14.6 °C in September. Even at its warmest the sea stays below 20 °C, so swimming is bracing at best.
Can you swim in San Francisco in October?
Only if you don't mind cold water: in October the sea averages just 13.9 °C. Comfortable swimming temperatures are not reached at any time of year.
What is the warmest month in San Francisco?
September is the warmest month, with average highs of 23 °C and nights around 13 °C. December is the coolest month at 14 °C.
When does it rain most in San Francisco?
The wettest month is February with 93 mm of precipitation. The driest month is July with 0 mm.
How many hours of sunshine does San Francisco get?
San Francisco gets around 2,900 hours of sunshine a year. The sunniest month is June with 10.9 hours a day; in December there are 4.8 hours a day.
What time zone is San Francisco in?
San Francisco uses the time zone America/Los_Angeles: UTC−8 in January and UTC−7 in July.
How long is the flight from London to San Francisco?
A nonstop flight from London to San Francisco takes about 10 h 50 min, for a straight-line distance of about 8,600 km.
Near San Francisco
Other destinations close by.
Places with a climate like San Francisco
Destinations whose weather through the year is closest to San Francisco's – good alternatives.