Contents
- Weather in August
- Frequently asked questions
- Average temperature in August
- Average pressure in August
- Average wind speed in August
- Average humidity in August
- Average rainfall in August
- Average rainfall days in August
- Average daylight in August
- Average sunshine in August
- Average sunshine days in August
- Average UV index in August
- Average cloud cover in August
- Average visibility in August
Weather in August
Temperature
August and September, when the average high-temperature reaches 71.2°F (21.8°C), are the warmest months.Humidity
The months with the highest humidity are March and August, with an average relative humidity of 76%.Rainfall
In Foster City, rain does not fall in June through August.Daylight
In Foster City, the average length of the day in August is 13h and 34min.On the first day of the month, sunrise is at 6:13 am and sunset at 8:16 pm. On the last day of August, sunrise is at 6:39 am and sunset at 7:39 pm PDT.
Sunshine
In Foster City, the average sunshine in August is 11.8h.UV index
The months with the highest UV index are June through September, with an average maximum UV index of 5. A UV Index estimate of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for average individuals.Note: In August, the maximum UV index of 5 translates into these guidelines:
Undertake protective steps - Recommendations to avoid sunburn are issued. Sun's radiation is most powerful around mid-day, so it's best to limit outdoor activities during this time. During bright days, sunglasses that offer UVA and UVB defense are recommended.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What time of the year is the hottest?
What is the usual temperature for Foster City in August?
What are the most humid months?
What is the average humidity in August?
What is the driest month?
Does it rain in August?
How many hours of daylight does Foster City have in August?
When are sunrise and sunset in August in Foster City?
How long on average sun shines in August in Foster City?
What are the months with the highest UV index?
What is the UV index reading in August in Foster City?
Average temperature in August
Foster City, CA
- Average high temperature in August: 71.2°F
The warmest months (with the highest average high temperature) are August and September (71.2°F).
The month with the lowest average high temperature is December (55.8°F).
- Average low temperature in August: 56.3°F
The month with the highest average low temperature is September (56.7°F).
The coldest month (with the lowest average low temperature) is January (46.9°F).
Average pressure in August
Foster City, CA
- Average pressure in August: 29.93"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 August
Foster City, CA
- Average wind speed in August: 5.9mph
The windiest month (with the highest average wind speed) is April (8mph).
The calmest months (with the lowest average wind speed) are August, September and October (5.9mph).
Average humidity in August
Foster City, CA
- Average humidity in August: 76%
The months with the highest relative humidity are March and August (76%).
The months with the lowest relative humidity are October and November (70%).
Average rainfall in August
Foster City, CA
- Average rainfall in August: 0"
The wettest month (with the highest rainfall) is February (0.55").
The driest months (with the least rainfall) are June, July and August (0").
Average rainfall days in August
Foster City, CA
- Average rainfall days in August: 0.7 days
The month with the highest number of rainy days is March (6.8 days).
The month with the least rainy days is July (0.3 days).
Average daylight in August /
Average sunshine in August
Foster City, CA
- Average daylight in August: 13h and 4min
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 August: 11h and 5min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 54min).
Average sunshine days in August
Foster City, CA
- Average sunshine days in August: 30.2 days
The month with the most sunshine days is July (30.4 days).
The month with the least sunshine days is February (23.3 days).
Average UV index in August
Foster City, CA
- Average UV index in August: 5
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 August
Foster City, CA
- Average cloud cover in August: 13
The month with the most cloud cover is March (Cloud cover 35).
The month with the least cloud cover is July (Cloud cover 11).
Average visibility in August
Foster City, CA
- Average visibility in August: 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).
Foster City, California, USA
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