Mild
Average highs are around 26°C, so days are mild rather than hot.
September verdict
San Francisco, California, United States in September
Weather score69Good
Good for holiday weather
Average highs are around 26°C, so days are mild rather than hot. Sunshine averages 9.5h per day, so bright days are a strong part of the month. Rainfall averages 4mm, which is relatively low for holiday planning.
September weather
Monthly averages
Temp
26°C
Rain
4mm
Sun
9.5h
Sea
15°C
Weather score
69
Good
Seasonal climate calendar
TemperatureTemp
RainRain
SunSun
SwimSwim
Weather scoreWeather score
Trip feel
Drier
Rainfall averages 4mm, which is relatively low for holiday planning.
Bright
Sunshine averages 9.5h per day, so bright days are a strong part of the month.
Cool sea
Sea temperatures average 15°C, so the water can feel cool.
Map
Weather map
Compare San Francisco, California, United States with nearby places by weather score, rain, sun, temperature, and swim conditions.
Temperature
September26°C average high
September is one of San Francisco's warmest months, with daytime heat above the yearly average.
Warmest monthsJune to October
This stretch sets the upper range for average daytime heat.
Rain
September4mm average rain
September is one of San Francisco's driest months, making outdoor days easier to plan than in wetter parts of the year.
Driest monthsApril to October
This is the drier part of the year, when outdoor plans usually need less weather flexibility.
Sun
September9.5 hours average sun
September is brighter than San Francisco's yearly average, though the strongest sunshine usually sits closer to the peak months.
Brightest monthsApril to August
This stretch has the strongest sunshine in the monthly averages.
Sea temperature
September15°C average sea
September is one of San Francisco's warmest sea months, when swimming comfort is usually strongest.
Warmest seaJuly to October
Sea temperatures are usually near 14°C in this stretch, so swimming comfort is at its strongest.
Weather score
September69 weather score
September is one of San Francisco's best weather-score months, combining the strongest overall balance in the yearly averages.
Best weather monthsMay to September
These months have the strongest weather score in the monthly averages.
Hotels in San Francisco, California, United States
Marriott
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The Ritz-Carlton, San FranciscoSan Francisco, California, USA
The St. Regis San FranciscoSan Francisco, California, USA
JW Marriott San Francisco Union SquareSan Francisco, California, USA
Palace Hotel, a Luxury Collection Hotel, San FranciscoSan Francisco, California, USA
W San FranciscoSan Francisco, California, USA
San Francisco Marriott Fisherman's WharfSan Francisco, California, USA