April weather forecastSan Francisco, CA
April
Weather in April
April in San Francisco is characterized by drying conditions and warming trends. Compared to the month of March, rainfall in April reduces significantly to 0.28in, marking the transition from spring to early summer. The city dazzles under the April sun as temperatures continue to rise and days grow longer. Cloudy skies begin to clear, offering fantastic views of the city's landmarks. The shift towards summer continues into May, bringing even warmer temperatures and longer daylight hours.Temperature
As April takes its course, San Francisco's average high-temperature registers at a still refreshing 63.1°F (17.3°C), closely aligning with the preceding month. San Francisco usually reports an average low-temperature of 48.6°F (9.2°C) during the month of April.Humidity
In San Francisco, California, the average relative humidity in April is 73%.Rainfall
In San Francisco, during April, the rain falls for 4.8 days and regularly aggregates up to 0.28" (7mm) of precipitation. Throughout the year, there are 58.6 rainfall days, and 6.46" (164mm) of precipitation is accumulated.Ocean temperature
April through June, with an average ocean temperature of 53.1°F (11.7°C), are months with the coldest seawater.Note: Dipping into 53.1°F (11.7°C) below 50°F (10°C) is possible with the right protection; absent that, anticipate cold shock and hampered breathing. Swimming momentarily at 55.4°F (13°C) can be jarring.
Daylight
The average length of the day in April in San Francisco is 13h and 12min.On the first day of April, sunrise is at 6:53 am and sunset at 7:33 pm. On the last day of the month, sunrise is at 6:13 am and sunset at 7:59 pm PDT.
Sunshine
In San Francisco, the average sunshine in April is 10.4h.UV index
The months with the highest UV index are April, June through September, with an average maximum UV index of 5. A UV Index estimate of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV radiation for the ordinary person.Note: A maximum high daily UV index of 5 during April translates into the following directions:
Undertake protective steps - Recommendations to avoid sunburn are issued. UV radiation is strongest from the Sun during midday; protect yourself by staying in shaded areas. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in April
San Francisco, CA
- Average high temperature in April: 63.1°F
The warmest month (with the highest average high temperature) is September (73.2°F).
The month with the lowest average high temperature is December (55.8°F).
- Average low temperature in April: 48.6°F
The month with the highest average low temperature is September (56.7°F).
The coldest months (with the lowest average low temperature) are January and December (45.9°F).
Average pressure in April
San Francisco, CA
- Average pressure in April: 30.03"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.92"Hg).
Average wind speed in April
San Francisco, CA
- Average wind speed in April: 7.5mph
The windiest month (with the highest average wind speed) is May (7.6mph).
The calmest month (with the lowest average wind speed) is November (5.5mph).
Average humidity in April
San Francisco, CA
- Average humidity in April: 73%
The month with the highest relative humidity is March (76%).
The month with the lowest relative humidity is October (67%).
Average rainfall in April
San Francisco, CA
- Average rainfall in April: 0.28"
The wettest month (with the highest rainfall) is February (1.38").
The driest months (with the least rainfall) are July, August and September (0.08").
Average rainfall days in April
San Francisco, CA
- Average rainfall days in April: 4.8 days
The month with the highest number of rainy days is March (9.3 days).
The month with the least rainy days is June (1.9 days).
Average sea temperature in April
San Francisco, CA
- Average sea temperature in April: 53°F
The best month for swimming (with the highest average sea temperature) is September (57.3°F).
The coldest months (with the lowest average sea temperature) are April and June (53°F).
Average daylight in April /
Average sunshine in April
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 24min
The month with the most sunshine is July (Average sunshine: 11h and 48min).
The month with the least sunshine is December (Average sunshine: 5h and 48min).
Average sunshine days in April
San Francisco, CA
- Average sunshine days in April: 24.4 days
The month with the most sunshine days is October (25.8 days).
The month with the least sunshine days is March (20.8 days).
Average UV index in April
San Francisco, CA
- Average UV index in April: 5
The months with the highest UV index are April, June, July, August and September (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in April
San Francisco, CA
- Average cloud cover in April: 27
The month with the most cloud cover is March (Cloud cover 36).
The months with the least cloud cover are July and September (Cloud cover 14).
Average visibility in April
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).
