August weather forecast
San Francisco, CA

A beautiful dusk view of the Golden Gate Bridge in San Francisco, California
A beautiful dusk view of the Golden Gate Bridge in San Francisco, California

Weather in August

August, the last month of the summer in San Francisco, is also an agreeable month, with an average temperature ranging between max 72.5°F (22.5°C) and min 56.3°F (13.5°C).

Temperature

In San Francisco, the average high-temperature in August is practically the same as in July - a still agreeable 72.5°F (22.5°C). The average low-temperature, in August, is 56.3°F (13.5°C).

Humidity

The average relative humidity in August in San Francisco, California, is 74%.

Rainfall

July through September are months with the least rain in San Francisco when the rain falls for 2.7 days and typically aggregates up to 0.08" (2mm) of rain.

Ocean temperature

In August, the average ocean temperature in San Francisco is 56.7°F (13.7°C).
Note: At temperatures below 50°F (10°C), swimming in a suitably protected swimsuit is feasible; otherwise, cold shock and loss of breathing control are imminent. Even a short swim, without thermal protection, at temperatures around 55.4°F (13°C) is not comfortable.

Daylight

The average length of the day in August in San Francisco is 13h and 34min.
On the first day of August, sunrise is at 6:13 am and sunset at 8:18 pm. On the last day of the month, sunrise is at 6:38 am and sunset at 7:40 pm PDT.

Sunshine

In San Francisco, California, the average sunshine in August is 11.6h.

UV index

The months with the highest UV index in San Francisco are April, June through September, with an average maximum UV index of 5. A UV Index value of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV radiation for average individuals.
Note: In August, the average maximum UV index of 5 translate into the following recommendations:
Take precautions - Protection against sun damage is advised. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun.
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FAQ

What is the temperature in August in San Francisco?

The average high-temperature, in August, in San Francisco, California, is 72.5°F (22.5°C), while the average low-temperature is 56.3°F (13.5°C).

What is the average humidity in August in San Francisco?

The average relative humidity in August in San Francisco, California, is 74%.

What is the driest month in San Francisco?

The months with the least rainfall are July through September Rain falls for 2.7 days and accumulates 0.08" (2mm) of rain.

How many days does it rain in August in San Francisco?

In San Francisco, in August, it is raining for 2.7 days, with typically 0.08" (2mm) of accumulated precipitation.

How cold is the water in August in San Francisco?

In San Francisco, in August, the average water temperature is 56.7°F (13.7°C). Swimming in 56.7°F (13.7°C) is considered life-threatening. Even a few minutes in 55.4°F (13°C) water is uncomfortable, and swimming below 50°F (10°C) may cause total loss of breathing control and cold shock, depending on a person's physique.

What is the average length of the day in August in San Francisco?

In August, the average day length is 13h and 34min.

When is the sunrise / sunset in August in San Francisco?

In August, on the first day of the month, sunrise is at 6:13 am and sunset at 8:18 pm. On the last day of the month, sunrise is at 6:38 am and sunset at 7:40 pm PDT.

How long on average sun shines in August in San Francisco?

In San Francisco, the average sunshine duration in August is 11.6h.

What is the month with the highest UV index in San Francisco?

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

What is the UV index reading in August in San Francisco?

The average daily maximum UV index in August is 5. A UV Index value of 3 to 5 symbolizes a medium hazard to health from exposure to Sun's UV rays.

Average temperature in August
San Francisco, CA

Average temperature in August - San Francisco, CA
  • Average high temperature in August: 72.5°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 August: 56.3°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).

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Average pressure in August
San Francisco, CA

Average pressure in August - San Francisco, 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).

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Average wind speed in August
San Francisco, CA

Average wind speed in August - San Francisco, CA
  • Average wind speed in August: 6.2mph

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).

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Average humidity in August
San Francisco, CA

Average humidity in August - San Francisco, CA
  • Average humidity in August: 74%

The month with the highest relative humidity is March (76%).
The month with the lowest relative humidity is October (67%).

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Average rainfall in August
San Francisco, CA

Average rainfall in August - San Francisco, CA
  • Average rainfall in August: 0.08"

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").

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Average rainfall days in August
San Francisco, CA

Average rainfall days in August - San Francisco, CA
  • Average rainfall days in August: 2.7 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).

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Average sea temperature in August
San Francisco, CA

Average sea temperature in August - San Francisco, CA
  • Average sea temperature in August: 56.7°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).

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

Average daylight in August / Average sunshine in August - San Francisco, CA
  • Average daylight in August: 13h and 34min

The month with the longest days is June (Average daylight: 14h and 44min).
The month with the shortest days is December (Average daylight: 9h and 36min).

  • Average sunshine in August: 11h and 36min

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).

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Average sunshine days in August
San Francisco, CA

Average sunshine days in August - San Francisco, CA
  • Average sunshine days in August: 23.1 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).

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Average UV index in August
San Francisco, CA

Average UV index in August - San Francisco, 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).

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Average cloud cover in August
San Francisco, CA

Average cloud cover in August - San Francisco, CA
  • Average cloud cover in August: 16

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).

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Average visibility in August
San Francisco, CA

Average visibility in August - San Francisco, 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).

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