August weather forecastSunnyvale, CA
August
Weather in August
August in Sunnyvale witnesses a slight decrease in average high temperature, accompanied by a virtually identical level of rainfall and humidity as July. Despite the brilliance of the summer sun, the maximum measured wind speed drops to 5.3mph (8.5km/h), indicating mellow breezy days. The UV index, pressure rating, and visibility remain stable, contributing to consistent weather conditions throughout the month. Even though August still carries the warmth of the peak summer, the month brings in a hint of incoming autumn.Temperature
August brings an average high-temperature of a still warm 79.3°F (26.3°C), nearly identical to the preceding month. Sunnyvale records a consistent low-temperature average of 56.8°F (13.8°C) during August, indicating a significant difference from the daytime heat.Humidity
In August, the average relative humidity is 66%.Rainfall
January through June, August through December are months with rainfall. August is the first month it rains. Throughout August, in the average 0.4 rainfall days, it receives 0.04" (1mm) of precipitation. Throughout the year, there are 50 rainfall days, and 3.9" (99mm) of precipitation is accumulated.Daylight
The average length of the day in August is 13h and 33min.On the first day of August, sunrise is at 6:13 am and sunset at 8:15 pm. On the last day of the month, sunrise is at 6:38 am and sunset at 7:37 pm PDT.
Sunshine
The average sunshine in August is 12h.UV index
In Sunnyvale, California, the average daily maximum UV index in August is 5. A UV Index reading of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV rays for the average person.Note: In August, the maximum UV index of 5 transforms into these recommendations:
Undertake precautions - Obligation exists to protect against skin and eye damage. Protect yourself from the midday Sun's peak UV radiation by minimizing exposure. Sunglasses providing both UVA and UVB protection are non-negotiable on sunlit days.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in August
Sunnyvale, CA
- Average high temperature in August: 79.3°F
The warmest month (with the highest average high temperature) is July (79.9°F).
The month with the lowest average high temperature is December (56.8°F).
- Average low temperature in August: 56.8°F
The month with the highest average low temperature is August (56.8°F).
The coldest months (with the lowest average low temperature) are February and December (44.2°F).
Average pressure in August
Sunnyvale, CA
- Average pressure in August: 29.93"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The months with the lowest atmospheric pressure are June and September (29.92"Hg).
Average wind speed in August
Sunnyvale, CA
- Average wind speed in August: 4.7mph
The windiest month (with the highest average wind speed) is April (6.2mph).
The calmest month (with the lowest average wind speed) is September (4.6mph).
Average humidity in August
Sunnyvale, CA
- Average humidity in August: 66%
The month with the highest relative humidity is March (73%).
The months with the lowest relative humidity are September and October (63%).
Average rainfall in August
Sunnyvale, CA
- Average rainfall in August: 0.04"
The wettest months (with the highest rainfall) are February and March (0.75").
The driest month (with the least rainfall) is July (0").
Average rainfall days in August
Sunnyvale, CA
- Average rainfall days in August: 0.4 days
The month with the highest number of rainy days is March (9.6 days).
The month with the least rainy days is August (0.4 days).
Average daylight in August /
Average sunshine in August
Sunnyvale, CA
- Average daylight in August: 13h and 36min
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: 12h and 0min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 5h and 54min).
Average sunshine days in August
Sunnyvale, CA
- Average sunshine days in August: 30.1 days
The month with the most sunshine days is August (30.1 days).
The month with the least sunshine days is March (19.9 days).
Average UV index in August
Sunnyvale, CA
- Average UV index in August: 5
The month with the highest UV index is June (UV index 6).
The months with the lowest UV index are February, November and December (UV index 3).
Average cloud cover in August
Sunnyvale, CA
- Average cloud cover in August: 8
The month with the most cloud cover is March (Cloud cover 35).
The month with the least cloud cover is July (Cloud cover 7).
Average visibility in August
Sunnyvale, 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).
