October 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 October

October in San Mateo brings the essence of autumn with a slight drop in temperature. October's weather is delightfully moderate and a stark departure from the persistent warmth experienced in September. The focus in October shifts toward increasing amounts of rainfall, where rainfall mounts to 0.04" (1mm) much from nothing in the previous month. Despite the start of the annual rainy season, October can be quite pleasant, accommodating a quality outdoor experience.

Temperature

San Mateo greets October with an average high-temperature of a refreshing 67.8°F (19.9°C), marking a slight deviation from the preceding month. In the month of October, San Mateo experiences an average low-temperature of 55.2°F (12.9°C).

Humidity

The months with the lowest humidity are October and November, with an average relative humidity of 70%.

Rainfall

In San Mateo, in October, during 1.4 rainfall days, 0.04" (1mm) of precipitation is typically accumulated. Throughout the year, there are 32.6 rainfall days, and 2.13" (54mm) of precipitation is accumulated.

Daylight

In San Mateo, the average length of the day in October is 11h and 13min.
On the first day of the month, sunrise is at 7:05 am and sunset at 6:51 pm. On the last day of October, sunrise is at 7:34 am and sunset at 6:11 pm PDT.

Sunshine

The average sunshine in October in San Mateo is 7.1h.

UV index

In San Mateo, the average daily maximum UV index in October is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for ordinary individuals.
Note: The maximum daily UV index, 4 in October, converts into the following recommendations:
Adopt protective measures - Suggestions to resist sunburn are offered. Avoid the Sun's strongest UV rays by seeking shade and limiting exposure during midday. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes.

Frequently asked questions

What are October temperatures?

The high-temperature during October is 67.8°F (19.9°C) and the low-temperature is 55.2°F (12.9°C).

What is the least humid month?

October and November, with an average relative humidity of 70%, are the least humid months.

What is the average humidity in October?

The average relative humidity in October in San Mateo is 70%.

How many days does it rain in October?

In San Mateo, in October, during 1.4 rainfall days, 0.04" (1mm) of precipitation is typically accumulated.

What is the average length of the day in October?

The average day length in October is 11h and 13min.

When are sunrise and sunset in October?

On the first day of October, sunrise is at 7:05 am and sunset at 6:51 pm. On the last day of the month, sunrise is at 7:34 am and sunset at 6:11 pm PDT.

How many hours of sunshine does San Mateo have in October?

In October, the average sunshine duration is 7.1h.

What is the UV index intensity in October?

In October, the average daily maximum UV index in San Mateo is 4. A UV Index value of 3 to 5 symbolizes a medium hazard to health from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in October
San Mateo, CA

Average temperature in October - San Mateo, CA
  • Average high temperature in October: 67.8°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 October: 55.2°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 October
San Mateo, CA

Average pressure in October - San Mateo, CA
  • Average pressure in October: 29.99"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 October
San Mateo, CA

Average wind speed in October - San Mateo, CA
  • Average wind speed in October: 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 October
San Mateo, CA

Average humidity in October - San Mateo, CA
  • Average humidity in October: 70%

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 October
San Mateo, CA

Average rainfall in October - San Mateo, CA
  • Average rainfall in October: 0.04"

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 October
San Mateo, CA

Average rainfall days in October - San Mateo, CA
  • Average rainfall days in October: 1.4 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 October /
Average sunshine in October
San Mateo, CA

Average daylight in October / Average sunshine in October - San Mateo, CA
  • Average daylight in October: 11h and 1min

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 October: 7h and 1min

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 October
San Mateo, CA

Average sunshine days in October - San Mateo, CA
  • Average sunshine days in October: 28.8 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 October
San Mateo, CA

Average UV index in October - San Mateo, CA
  • Average UV index in October: 4

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 October
San Mateo, CA

Average cloud cover in October - San Mateo, CA
  • Average cloud cover in October: 17

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 October
San Mateo, CA

Average visibility in October - San Mateo, CA
  • Average visibility in October: 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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