nomadseason

April Weather in South San Francisco, United States

Last updated: June 24, 2025

In April, the average temperature in South San Francisco, United States is a mild 13°C (55°F), with a minimum of 7°C (44°F) and a comfortable maximum reaching 28°C (82°F). Expect about 35 mm (1.4 in) of precipitation spread over 5 days, contributing to an average humidity of 79%. Enjoy the blend of cool and warm days this month!

April Temperature in South San Francisco

In April in South San Francisco, the average temperature is 13°C (55°F). Maximums can reach 28°C (82°F), while minimums can dip as low as 7°C (44°F). This moderate climate makes South San Francisco an ideal destination for travelers seeking pleasant weather for exploration and outdoor activities.

April Weather in South San Francisco: Daily Temperature Highs, Lows, and Averages

The chart illustrates April temperature patterns in South San Francisco, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In South San Francisco, April typically has an average temperature of 13°C (55°F), with highs reaching up to 28°C (82°F) and lows dropping to around 7°C (44°F).
JanFebMarAprMayJunJulAugSepOctNovDec515253555659596162605552
Data source: Temperature data for South San Francisco generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

April Precipitation in South San Francisco

In South San Francisco in April, the precipitation amount is 35 mm (1.4 in) over a span of 5 days.

April Precipitation Trends in South San Francisco

The chart displays monthly precipitation patterns in South San Francisco, with values for each month alongside April’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how April’s conditions compare to those of other months. In South San Francisco, April typically receives around 35 mm (1.4 inches) of precipitation spread over approximately 5 days.
JanFebMarAprMayJunJulAugSepOctNovDec1061097835203322305095
Data source: Precipitation data for April generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

April Humidity in South San Francisco

In South San Francisco in April humidity is 79%. With an average temperature of 13°C (55°F), this humidity feels like a damp chill that permeates clothing, making outdoor activities slightly uncomfortable and prompting travelers to seek shelter or dress in layers to stay warm while adjusting to the moist air.

April Average Humidity in South San Francisco

This chart illustrates the average monthly humidity levels in South San Francisco, with April’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In April, average humidity in South San Francisco is approximately 79%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec85%82%82%79%83%84%87%87%86%80%79%79%
Data source: Humidity data for April generated using information from the Copernicus Climate Change Service.

April UV Index in South San Francisco

In South San Francisco in April, the maximum UV index is 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For detailed information, you can check the Hourly UV Index in South San Francisco.

Maximum UV Index Levels in South San Francisco for April

The chart shows the monthly maximum UV Index (UVI) for South San Francisco in April, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In April, the maximum UV index in South San Francisco typically reaches 9, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec3589101111109743
Data source: South San Francisco April UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

How April Weather in South San Francisco Compares to Other Months

Weather in South San Francisco varies notably across the year, with each month offering distinct climate conditions. This page compares April’s weather to other months in South San Francisco, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in South San Francisco, showing how April’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather11°C (52°F)106 mm (4.2 inches)85%moderate
February Weather11°C (52°F)109 mm (4.3 inches)82%moderate
March Weather12°C (53°F)78 mm (3.1 inches)82%very high
April Weather13°C (55°F)35 mm (1.4 inches)79%very high
May Weather14°C (57°F)20 mm (0.8 inches)83%very high
June Weather15°C (60°F)3 mm (0.1 inches)84%extreme
July Weather15°C (60°F)3 mm (0.1 inches)87%extreme
August Weather16°C (61°F)2 mm (0.1 inches)87%very high
September Weather17°C (63°F)2 mm (0.1 inches)86%very high
October Weather16°C (60°F)30 mm (1.2 inches)80%high
November Weather13°C (56°F)50 mm (2.0 inches)79%moderate
December Weather11°C (52°F)95 mm (3.7 inches)79%moderate

Compare South San Francisco's Climate with Cities Worldwide