The best times to visit South San Francisco for ideal weather are

April 30th to November 11th

based on average temperature and humidity from NOAA (the National Oceanic and Atmospheric Administration). Read below for more weather and travel details.

 

 


Other South San Francisco Travel Info

Weather in South San Francisco

Temperature

Average temperatures in South San Francisco vary little. Considering humidity, temperatures feel nice most of the year, excluding some cold weeks in the winter, with a very low chance of rain or snow throughout the year. The area is more temperate than most — in the 63rd percentile for pleasant weather — compared to tourist destinations worldwide. Weeks with ideal weather are listed above. If you’re looking for the very warmest time to visit South San Francisco, the hottest months are September, August, and then July. See average monthly temperatures below. The warmest time of year is generally late August to early September where highs are regularly around 78.4°F (25.8°C) with temperatures rarely dropping below 57.1°F (13.9°C) at night.

South San Francisco Temperatures (Fahrenheit)

Key
High
Average
Low

South San Francisco Temperatures (Celsius)

Key
High
Average
Low

“Feels-Like” Temperatures

The way we experience weather isn’t all about temperature. Higher temperatures affect us much more at higher humidity, and colder temperatures feel piercing with high winds. Our perceived temperatures factor in humidity and wind chill to better represent how hot or cold the day feels to a person.

South San Francisco Perceived Temperature (F)

Key
High
Average
Low

South San Francisco Perceived Temperature (C)

Key
High
Average
Low

 

Average South San Francisco Temperatures by Month

Daily highs (averaged for the month) usually give the best indication of the weather. A significantly lower mean and low generally just means it gets colder at night.

Show Fahrenheit

Month Avg. High (°F) Avg. Mean (°F) Avg. Low (°F)
Jan 59 50.5 43.2
Feb 61.1 52.4 45.4
Mar 64.7 54.3 47.2
Apr 66.9 55.5 48.4
May 68.7 57.7 50.9
Jun 72.3 60.5 53.4
Jul 73 61.9 55.8
Aug 73.8 62.6 56.4
Sep 76.2 63.5 56.3
Oct 73.9 61.9 54.4
Nov 65.2 56 48.5
Dec 58.2 51 44.1

Show Celsius

Month Avg. High (°C) Avg. Mean (°C) Avg. Low (°C)
Jan 15 10.3 6.2
Feb 16.2 11.3 7.4
Mar 18.2 12.4 8.4
Apr 19.4 13.1 9.1
May 20.4 14.3 10.5
Jun 22.4 15.8 11.9
Jul 22.8 16.6 13.2
Aug 23.2 17 13.6
Sep 24.6 17.5 13.5
Oct 23.3 16.6 12.4
Nov 18.4 13.3 9.2
Dec 14.6 10.6 6.7

 


 

Precipitation (Rain or Snow)

If dry weather is what you’re after, the months with the lowest chance of significant precipitation in South San Francisco are July, August, and then May. Note that we define “significant precipitation” as .1 inches or more in this section. The lowest chance of rain or snow occurs around late May. For example, on the week of May 21st there are no days of precipitation on average. By contrast, it’s most likely to rain or snow in mid December with an average of 2 days of significant precipitation the week of December 17th.

When can you find snow in South San Francisco? Weather stations report no annual snow. Please note that a value of 0 for snow in the graph below may either mean there was no snow, or that snow is unreported.

Chance of Precipitation

The graph below shows the % chance of rainy and snowy days in South San Francisco.

Key
Days with precipitation

Snow on the Ground

The graph below shows the average snow on the ground in South San Francisco (in).

Key
Snow depth

Average Rain and Snow by Month

Show Inches

Month Daily Chance of Rain Average Snow Depth (in) Total Precipitation (in)
Jan 12% 0 2.1
Feb 23% 0 3
Mar 13% 0 1.9
Apr 11% 0 1.4
May 2% 0 0.2
Jun 2% 0 0.2
Jul 0% 0 0
Aug 0% 0 0
Sep 2% 0 0.1
Oct 5% 0 0.9
Nov 14% 0 1.5
Dec 23% 0 4.2

Show Centimeters

Month Daily Chance of Rain Average Snow Depth (cm) Total Precipitation (cm)
Jan 12 0 5.3
Feb 23 0 7.6
Mar 13 0 4.8
Apr 11 0 3.6
May 2 0 0.5
Jun 2 0 0.5
Jul 0 0 0
Aug 0 0 0
Sep 2 0 0.3
Oct 5 0 2.3
Nov 14 0 3.8
Dec 23 0 10.7

 

Humidity and Wind

South San Francisco has some high humidity months, with other comfortably humid months. The least humid month is April (59% relative humidity), and the most humid month is February (68.1%).

Wind in South San Francisco is usually moderate. The windiest month is May, followed by June and April. May’s average wind speed of around 12 knots (13.8 MPH or 22.2 KPH) is considered “a moderate breeze.” Maximum sustained winds (the highest speed for the day lasting more than a few moments) are at their highest in late May where average top sustained speeds reach 23.8 knots, which is considered a strong breeze.

Relative Humidity (%)

The graph below shows the average % humidity by month in South San Francisco.

Key
Avg. Relative Humidity

Wind

The graph below shows wind speed (max and average) in knots.

Key
Max Sustained Wind
Average Daily Wind

Average Wind Speeds

Show Wind Speeds

All wind speeds are in knots. 1 knot = 1.15 MPH or 1.85 KPH.

Month Avg. Wind Avg. Wind Feel Sustained High Wind High Wind Feel
Jan 4.8 Light breeze 12.3 Significant breeze
Feb 7.2 Gentle breeze 16.7 Significant breeze
Mar 8.7 Gentle breeze 19.1 Significant breeze
Apr 11.1 Significant breeze 22.1 Very strong breeze
May 12 Significant breeze 22.6 Significant breeze
Jun 11.3 Significant breeze 21.4 Strong breeze
Jul 10.6 Gentle breeze 19.9 Significant breeze
Aug 10.3 Gentle breeze 20.4 Strong breeze
Sep 9.4 Gentle breeze 19.6 Significant breeze
Oct 7.6 Gentle breeze 17.6 Strong breeze
Nov 5.8 Light breeze 14.6 Significant breeze
Dec 5.9 Light breeze 13.8 Significant breeze

Show Relative Humidity by Month

Month Avg. Relative Humidity
Jan 67%
Feb 68.1%
Mar 64.4%
Apr 59%
May 59.1%
Jun 60.9%
Jul 65.5%
Aug 66.2%
Sep 62.2%
Oct 59.9%
Nov 63.9%
Dec 67%

 

Is it Safe to Travel to South San Francisco?

Our best data indicates this area is generally safe. As of Dec 04, 2023 there are no travel advisories or warnings for the United States; exercise normal security precautions. Check this page for any recent changes or regions to avoid: Travel Advice and Advisories. This advisory was last updated on Dec 04, 2023.


 

The Busiest and Least Crowded Months

The busiest month for tourism in South San Francisco, CA, US is July, followed by August and June. Prices for hotels and flights will be most expensive during these months, though you can save if you purchase well in advance. Tourists are unlikely to visit South San Francisco in November. Those willing to visit at these times will likely find it the least expensive month.

Estimated Tourism by Month

 

Most Popular Months to Visit

Key
Tourists Seeking Accommodations

Tourism graph is based on Google searches for services used by tourists relative to the rest of the year. Tourism data for this area is slightly extrapolated based on nearby areas. Displayed data is calculated relative to the peak, so a score of 57.9 in November means 57.9% of the tourists vs. July.

 

 

Overall South San Francisco Travel Experience by Season

Spring (March through May)

Humidity and temperatures combine to make this season feel moderate. Highs range from 71.5°F (21.9°C) and 61.6°F (16.4°C) with warmer temperatures in the later months. Rain is rare with 1 to 4 days of significant precipitation per month. Spring is the second busiest for tourism, which makes it a good time for those looking for things to do.

Summer (June through August)

The middle-year months have comfortably cool weather with high temperatures that are comfortable. These months see the least precipitation with 0 to 1 days of precipitation per month. June – August is the busiest season for tourism in South San Francisco, so lodging and other accommodations may cost more than usual.

Fall (September through November)

Fall daily highs range from 77.5°F (25.3°C) and 61.4°F (16.3°C), which will feel comfortable given the humidity and wind. It rains or snows a normal amount: 1 to 4 days per month. Tourism is the slowest during these months due to the weather, so hotels may be affordably priced.

Winter (December through February)

Weather is too cold this time of year in South San Francisco to be enjoyable for warm weather travelers. The average high during this season is between 62.1°F (16.7°C) and 56.5°F (13.6°C). On average, it rains or snows a fair amount: 4 to 7 times per month. These times of year are fairly slow with tourists.

 

Best Times to Travel› the United States › South San Francisco, CA, US