See exactly when rain will start and stop with a minute-by-minute precipitation nowcast for the next hour.
Compare today's weather with yesterday's data and track temperature trends over time.
Hourly Forecast
Daylight Hours
06:58
Sunrise
19:09
Sunset
Moon
Waxing Crescent
12:47
Moonrise
21:28
Moonset
Daily Forecast
Today
Thursday
Friday
Saturday
Sunday
Monday
Tuesday
Wednesday
Thursday
Friday
Air Quality Data Available
Upgrade to access real-time air quality data for South San Francisco.
Resources
UV Index
Humidity
Weather in South San Francisco today, September 16, 2026
Expect a muted, overcast feel in South San Francisco on September 16, 2026 as cloud persists. Brighter breaks, if they arrive, should stay brief. The first half of the day looks overcast, as cloud amounts reach about 100% around 10:00. Brighter weather, if it comes, waits until later.
Expect highs of 18°C and cooler readings close to 13°C. Relative humidity sits between 78% and 98%, reaching its peak around 07:00. Airflow remains manageable, reaching about 6.5 km/h around 15:00.
Afternoon skies stay clogged, peaking close to 100% near 13:00. The grey theme continues rather than clearing out. Visibility holds near 13.8 km, though it can fall to 12.2 km. The sun rises at 06:58 and sets at 19:09, for a total of 12 hours 11 minutes of sunlight today.
Overall, South San Francisco on September 16, 2026 stays grey and muted, so outdoor plans may want a flexible backup even with a high near 18°C.
Frequently asked questions about weather in South San Francisco
How warm does it get in South San Francisco?
The warmest month in South San Francisco is September, with average high temperatures of 20°C. The average temperature during this period is around 17°C.
How cold does it get in South San Francisco?
The coldest month in South San Francisco is December, with average low temperatures of 9°C. The average temperature during this period is around 11°C.
What is the wettest time of year in South San Francisco?
The wettest month in South San Francisco is January, with an average of 119mm of precipitation.
What is the driest time of year in South San Francisco?
The driest month in South San Francisco is August, with an average of 1mm of precipitation.
Explore more weather forecasts
- San Bruno, California
- New York City, New York
- Millbrae, California
- Los Angeles, California
- Daly City, California
- Brooklyn, New York
- Pacifica, California
- Chicago, Illinois
- Burlingame, California
- Houston, Texas
- Hillsborough, California
- Queens, New York
- San Mateo, California
- Phoenix, Arizona
- San Francisco, California
- Philadelphia, Pennsylvania
