April weather forecastSouth San Francisco, CA
April weather forecast for South San Francisco, California: April in South San Francisco, California, is a comfortable spring month, with an average temperature ranging between max 61.3°F (16.3°C) and min 49.3°F (9.6°C). On the last day of April, in South San Francisco, sunrise is at 6:14 am and sunset at 7:59 pm PDT.

April
Weather in April
April in South San Francisco, California, is a comfortable spring month, with an average temperature ranging between max 61.3°F (16.3°C) and min 49.3°F (9.6°C).Temperature
South San Francisco records a slight change with April's average high-temperatures adjusting to a still refreshing 61.3°F (16.3°C) from March's 58.5°F (14.7°C). South San Francisco, during the nights of April, experiences an average temperature drop to a chilly 49.3°F (9.6°C).Humidity
The average relative humidity in April is 75%.Rainfall
In South San Francisco, in April, it is raining for 5.3 days, with typically 0.2" (5mm) of accumulated precipitation. In South San Francisco, during the entire year, the rain falls for 53.6 days and collects up to 3.9" (99mm) of precipitation.Daylight
In South San Francisco, the average length of the day in April is 13h and 12min.On the first day of the month, sunrise is at 6:53 am and sunset at 7:32 pm. On the last day of April, in South San Francisco, sunrise is at 6:14 am and sunset at 7:59 pm PDT.
Sunshine
In South San Francisco, the average sunshine in April is 10.3h.UV index
The average daily maximum UV index in April is 4. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV rays for the average person.Note: A maximum high UV index of 4 in April translates into the following recommendations:
Preventative actions are necessary - Suggestions to safeguard against sun damage are in order. To prevent harmful UV exposure, minimize direct contact with the Sun around midday. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in April
South San Francisco, CA
- Average high temperature in April: 61.3°F
The warmest month (with the highest average high temperature) is September (70°F).
The month with the lowest average high temperature is December (55.6°F).
- Average low temperature in April: 49.3°F
The months with the highest average low temperature are August and September (56.5°F).
The coldest months (with the lowest average low temperature) are January, February and December (47.8°F).
Average pressure in April
South San Francisco, CA
- Average pressure in April: 30.04"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is September (29.92"Hg).
Average wind speed in April
South San Francisco, CA
- Average wind speed in April: 8.5mph
The windiest month (with the highest average wind speed) is April (8.5mph).
The calmest month (with the lowest average wind speed) is September (6.2mph).
Average humidity in April
South San Francisco, CA
- Average humidity in April: 75%
The month with the highest relative humidity is August (78%).
The months with the lowest relative humidity are October and November (71%).
Average rainfall in April
South San Francisco, CA
- Average rainfall in April: 0.2"
The wettest month (with the highest rainfall) is February (0.79").
The driest months (with the least rainfall) are June, July and August (0.04").
Average rainfall days in April
South San Francisco, CA
- Average rainfall days in April: 5.3 days
The month with the highest number of rainy days is March (9.4 days).
The month with the least rainy days is June (1.1 days).
Average daylight in April /
Average sunshine in April
South San Francisco, CA
- Average daylight in April: 13h and 12min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in April: 10h and 18min
The month with the most sunshine is July (Average sunshine: 11h and 42min).
The month with the least sunshine is December (Average sunshine: 5h and 48min).
Average sunshine days in April
South San Francisco, CA
- Average sunshine days in April: 23.1 days
The months with the most sunshine days are June, July and September (26.3 days).
The month with the least sunshine days is March (19.4 days).
Average UV index in April
South San Francisco, CA
- Average UV index in April: 4
The months with the highest UV index are June, July, August and September (UV index 5).
The months with the lowest UV index are February and December (UV index 3).
Average cloud cover in April
South San Francisco, CA
- Average cloud cover in April: 28
The month with the most cloud cover is March (Cloud cover 37).
The month with the least cloud cover is September (Cloud cover 16).
Average visibility in April
South San Francisco, CA
- Average visibility in April: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).





