August weather forecast
San Mateo, CA

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A breathtaking view of the scenic spot of the Devil
A breathtaking view of the scenic spot of the Devil's Slide Sheer Cliff over the pacific Coast in San Mateo, California

Weather in August

August weather in San Mateo stays in line with the warm and dry pattern established in July. Despite minimal changes in temperature from the previous month, the peak temperature this month records 71.2°F (21.8°C). As one of the driest months of the year, August is sterling for residents and tourists enthusiastic for open-air activities. With its balmy temperature, relatively low humidity, and maximum hours of sunshine, August embodies the perfect summer experience.

Temperature

The warmest period in San Mateo is usually observed in August and September, with the average high-temperature peaking at 71.2°F (21.8°C).

Humidity

The months with the highest humidity are March and August, with an average relative humidity of 76%.

Rainfall

In San Mateo, rain does not fall in June through August.

Daylight

In San Mateo, California, 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 11.8h.

UV index

The months with the highest UV index are June through September, with an average maximum UV index of 5. A UV Index of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for the average person.
Note: In August, the average maximum UV index of 5 translates into the following recommendations:
Act with care - The need to guard against sun damage is communicated. Avoiding the Sun during its peak radiation time around midday is a healthy practice. For holistic sun protection encompassing the eyes, ears, face, and neck, a wide-brim hat is key.

Frequently asked questions

What part of the year is the hottest?

August and September are identified as the warmest months, with an average high-temperature of 71.2°F (21.8°C).

What are the temperatures in San Mateo in August?

The high-temperature during August is 71.2°F (21.8°C) and the low-temperature is 56.3°F (13.5°C).

What is the most humid month in San Mateo?

March and August, with an average relative humidity of 76%, are most humid months.

What is the average humidity in August?

The average relative humidity in August is 76%.

What is the driest month?

June through August are months without rainfall.

Does it rain in August?

In San Mateo, in August, it doesn't rain. In September, it rains.

What is the average length of the day in August?

In August, the average day length 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 many hours of sunshine does San Mateo have in August?

The average sunshine duration in August is 11.8h.

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.

How high is the UV index in August?

In August, the average daily maximum UV index is 5. A UV Index value of 3 to 5 symbolizes a moderate vulnerability from exposure to Sun's UV rays.
Average humidity
Average rainfall
Average rainfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in August
San Mateo, CA

Average temperature in August - San Mateo, 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
San Mateo, CA

Average pressure in August - San Mateo, 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
San Mateo, CA

Average wind speed in August - San Mateo, 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
San Mateo, CA

Average humidity in August - San Mateo, 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
San Mateo, CA

Average rainfall in August - San Mateo, 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
San Mateo, CA

Average rainfall days in August - San Mateo, 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
San Mateo, CA

Average daylight in August / Average sunshine in August - San Mateo, 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
San Mateo, CA

Average sunshine days in August - San Mateo, 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
San Mateo, CA

Average UV index in August - San Mateo, 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
San Mateo, CA

Average cloud cover in August - San Mateo, 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
San Mateo, CA

Average visibility in August - San Mateo, 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 Mateo, California, USA

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