August weather forecast
South San Francisco, CA

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A sign in large font of the South San Francisco City, California, on the hills over the scenic home setting below
A sign in large font of the South San Francisco City, California, on the hills over the scenic home setting below

Weather in August

August, the last month of the summer in South San Francisco, is also an agreeable month, with an average temperature ranging between min 56.5°F (13.6°C) and max 69.1°F (20.6°C).

Temperature

South San Francisco sees the arrival of August with an average high-temperature of a still pleasant 69.1°F (20.6°C), indicating a subtle variation from July. South San Francisco records a consistent low-temperature of 56.5°F (13.6°C) during August nights.

Humidity

The most humid month is August, with an average relative humidity of 78%.

Rainfall

June through August are months with the least rain when the rain falls for 1.5 days and typically aggregates up to 0.04" (1mm) of rain.

Daylight

In South San Francisco, the average length of the day in August is 13h and 34min.
On the first day of the month, sunrise is at 6:14 am and sunset at 8:17 pm. On the last day of August, sunrise is at 6:39 am and sunset at 7:39 pm PDT.

Sunshine

The average sunshine in August is 11.5h.

UV index

June through September, with an average maximum UV index of 5, are months with the highest UV index. A UV Index estimate of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for the average person.
Note: The maximum daily UV index, 5 in August, converts into the following recommendations:
Be vigilant - Suggestions to stave off sun damage are provided. Being exposed to the midday Sun can have harmful effects due to strong UV radiation; always take precautions. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage.

Frequently asked questions

What is the temperature in August?

In South San Francisco, in August, the average high-temperature is 69.1°F (20.6°C), and the average low-temperature is 56.5°F (13.6°C).

What is the most humid month?

August is the most humid month, with an average relative humidity of 78%.

What is the average humidity in August?

In South San Francisco, the average relative humidity in August is 78%.

What is the driest month?

June through August are months with the least rain when the rain falls for 1.5 days and typically aggregates up to 0.04" (1mm) of rain.

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

In South San Francisco, in August, it is raining for 1.5 days, with typically 0.04" (1mm) of accumulated precipitation.

How many hours of daylight does South San Francisco have in August?

In South San Francisco, the average day length in August is 13h and 34min.

What time are sunrise and sunset in August?

In August, on the first day of the month, sunrise is at 6:14 am and sunset at 8:17 pm. On the last day of the month, sunrise is at 6:39 am and sunset at 7:39 pm PDT.

How long on average sun shines in August?

The average sunshine duration in August is 11.5h.

What is the month with the highest UV index?

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

What is the UV index intensity in August?

In South San Francisco, California, the average daily maximum UV index in August is 5. A UV Index estimate of 3 to 5 represents a medium health risk from unprotected exposure to 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
South San Francisco, CA

Average temperature in August - South San Francisco, CA
  • Average high temperature in August: 69.1°F

The warmest month (with the highest average high temperature) is September (70°F).
The month with the lowest average high temperature is December (55.6°F).

  • Average low temperature in August: 56.5°F

The months with the highest average low temperature are August and September (56.5°F).
The coldest months (with the lowest average low temperature) are January, February and December (47.8°F).

Average pressure in August
South San Francisco, CA

Average pressure in August - South San Francisco, 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
South San Francisco, CA

Average wind speed in August - South San Francisco, CA
  • Average wind speed in August: 6.3mph

The windiest month (with the highest average wind speed) is April (8.5mph).
The calmest month (with the lowest average wind speed) is September (6.2mph).

Average humidity in August
South San Francisco, CA

Average humidity in August - South San Francisco, CA
  • Average humidity in August: 78%

The month with the highest relative humidity is August (78%).
The months with the lowest relative humidity are October and November (71%).

Average rainfall in August
South San Francisco, CA

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

The wettest month (with the highest rainfall) is February (0.79").
The driest months (with the least rainfall) are June, July and August (0.04").

Average rainfall days in August
South San Francisco, CA

Average rainfall days in August - South San Francisco, CA
  • Average rainfall days in August: 1.5 days

The month with the highest number of rainy days is March (9.4 days).
The month with the least rainy days is June (1.1 days).

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

Average daylight in August / Average sunshine in August - South San Francisco, 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 3min

The month with the most sunshine is July (Average sunshine: 11h and 42min).
The month with the least sunshine is December (Average sunshine: 5h and 48min).

Average sunshine days in August
South San Francisco, CA

Average sunshine days in August - South San Francisco, CA
  • Average sunshine days in August: 25 days

The months with the most sunshine days are June, July and September (26.3 days).
The month with the least sunshine days is March (19.4 days).

Average UV index in August
South San Francisco, CA

Average UV index in August - South San Francisco, 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
South San Francisco, CA

Average cloud cover in August - South San Francisco, CA
  • Average cloud cover in August: 19

The month with the most cloud cover is March (Cloud cover 37).
The month with the least cloud cover is September (Cloud cover 16).

Average visibility in August
South San Francisco, CA

Average visibility in August - South 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).

South San Francisco, California, USA

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