August weather forecast
San Anselmo, CA

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Weather in August

In August, San Anselmo endures its warmest month with maximum temperatures reaching 71.2°F (21.8°C). The high heat comes with noticeable humidity of 76%. The long sunshine hours bode well for outdoor enthusiasts, despite a restraining reduction in daylight hours. The wind speed decreases a notch, offering limited relief from the summer temperatures. This drop in wind speed, coupled with minimal rainfall, results in calm, clear settings for most days.

Temperature

In August, the average high-temperature in San Anselmo registers at a still agreeable 71.2°F (21.8°C), nearly identical to July's 70.5°F (21.4°C). An average nighttime temperature of 55.4°F (13°C) is observed during August.

Humidity

In San Anselmo, the average relative humidity in August is 76%.

Rainfall

The months with the least rainfall are June through September Rain falls for 1.2 days and accumulates 0.04" (1mm) of rain.

Daylight

In San Anselmo, the average length of the day in August is 13h and 35min.
On the first day of the month, sunrise is at 6:14 am and sunset at 8:18 pm. On the last day of August, sunrise is at 6:40 am and sunset at 7:40 pm PDT.

Sunshine

In San Anselmo, the average sunshine in August is 10.9h.

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 reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for average individuals.
Note: The UV index of 5 in August translates into these instructions:
Take heed. Individuals of lighter complexion can be burned in less than half an hour. To prevent harmful UV exposure, minimize direct contact with the Sun around midday. Experience reduced UV exposure by about half when donning a wide-brim hat.
Updated: Jun 17, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the temperature in August?

An average high-temperature, in August, in San Anselmo, is 71.2°F (21.8°C) and the average low-temperature is 55.4°F (13°C).

What is the average humidity in August?

In August, the average relative humidity is 76%.

What is the driest month?

The months with the least rainfall are June through September Rain falls for 1.2 days and accumulates 0.04" (1mm) of rain.

How much does it rain in August?

In San Anselmo, in August, during 1.2 rainfall days, 0.04" (1mm) of precipitation is typically accumulated.

What is the average length of the day in August?

In August, the average day length is 13h and 35min.

When is the sunrise / sunset in August?

On the first day of August, sunrise is at 6:14 am and sunset at 8:18 pm. On the last day of the month, sunrise is at 6:40 am and sunset at 7:40 pm PDT.

How long on average sun shines in August?

The average sunshine duration in August is 10.9h.

When is the highest UV index?

April, June through September, with an average maximum UV index of 5, are months with the highest UV index.

What is the UV index reading in August?

The average daily maximum UV index in August is 5. A UV Index reading of 3 to 5 represents a moderate health threat from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in August
San Anselmo, CA

Average temperature in August - San Anselmo, CA
  • Average high temperature in August: 71.2°F

The warmest month (with the highest average high temperature) is September (72.3°F).
The month with the lowest average high temperature is December (55.4°F).

  • Average low temperature in August: 55.4°F

The month with the highest average low temperature is September (56.1°F).
The coldest month (with the lowest average low temperature) is December (45.3°F).

Average pressure in August
San Anselmo, CA

Average pressure in August - San Anselmo, CA
  • Average pressure in August: 29.92"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 August
San Anselmo, CA

Average wind speed in August - San Anselmo, CA
  • Average wind speed in August: 6.4mph

The windiest month (with the highest average wind speed) is May (7.8mph).
The calmest months (with the lowest average wind speed) are October and November (5.5mph).

Average humidity in August
San Anselmo, CA

Average humidity in August - San Anselmo, CA
  • Average humidity in August: 76%

The month with the highest relative humidity is March (77%).
The month with the lowest relative humidity is October (68%).

Average rainfall in August
San Anselmo, CA

Average rainfall in August - San Anselmo, CA
  • Average rainfall in August: 0.04"

The wettest month (with the highest rainfall) is February (0.87").
The driest months (with the least rainfall) are June, July, August and September (0.04").

Average rainfall days in August
San Anselmo, CA

Average rainfall days in August - San Anselmo, CA
  • Average rainfall days in August: 1.2 days

The month with the highest number of rainy days is March (8.8 days).
The months with the least rainy days are June and August (1.2 days).

Average daylight in August /
Average sunshine in August
San Anselmo, CA

Average daylight in August / Average sunshine in August - San Anselmo, CA
  • Average daylight in August: 13h and 4min

The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 36min).

  • Average sunshine in August: 10h and 5min

The month with the most sunshine is July (Average sunshine: 11h and 12min).
The month with the least sunshine is December (Average sunshine: 5h and 30min).

Average sunshine days in August
San Anselmo, CA

Average sunshine days in August - San Anselmo, CA
  • Average sunshine days in August: 24.8 days

The month with the most sunshine days is June (26.4 days).
The month with the least sunshine days is March (20.7 days).

Average UV index in August
San Anselmo, CA

Average UV index in August - San Anselmo, CA
  • Average UV index in August: 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 August
San Anselmo, CA

Average cloud cover in August - San Anselmo, CA
  • Average cloud cover in August: 25

The month with the most cloud cover is March (Cloud cover 39).
The month with the least cloud cover is September (Cloud cover 19).

Average visibility in August
San Anselmo, CA

Average visibility in August - San Anselmo, 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).

San Anselmo, California, USA

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