Contents
- Weather in January
- Frequently asked questions
- Average temperature in January
- Average pressure in January
- Average wind speed in January
- Average humidity in January
- Average rainfall in January
- Average rainfall days in January
- Average daylight in January
- Average sunshine in January
- Average sunshine days in January
- Average UV index in January
- Average cloud cover in January
- Average visibility in January
Weather in January
Temperature
The arrival of January in San Mateo records an average high-temperature of a still refreshing 56.8°F (13.8°C), closely related to the 55.8°F (13.2°C) observed in December. January witnesses an average nighttime temperature of 46.9°F (8.3°C) in San Mateo.Humidity
In San Mateo, the average relative humidity in January is 73%.Rainfall
In San Mateo, during January, the rain falls for 4.4 days and regularly aggregates up to 0.31" (8mm) of precipitation. Throughout the year, there are 32.6 rainfall days, and 2.13" (54mm) of precipitation is accumulated.Daylight
In January, the average length of the day in San Mateo is 9h and 55min.On the first day of the month, sunrise is at 7:24 am and sunset at 5:01 pm. On the last day of January, in San Mateo, sunrise is at 7:13 am and sunset at 5:31 pm PST.
Sunshine
In San Mateo, the average sunshine in January is 6.2h.UV index
In San Mateo, the average daily maximum UV index in January is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV rays for average individuals.Note: In January, the maximum UV index of 4 transforms into these recommendations:
Undertake protective steps - Preventing 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. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat.
Frequently asked questions
What are the temperatures in San Mateo in January?
What is the average humidity in January in San Mateo?
How much does it rain in San Mateo in January?
What is the average length of the day in January in San Mateo?
When is the sunrise / sunset in January in San Mateo?
How long on average sun shines in January in San Mateo?
What is the UV index reading in January in San Mateo?
Average temperature in January
San Mateo, CA
- Average high temperature in January: 56.8°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 January: 46.9°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 January
San Mateo, CA
- Average pressure in January: 30.13"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 January
San Mateo, CA
- Average wind speed in January: 6.2mph
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 January
San Mateo, CA
- Average humidity in January: 73%
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 January
San Mateo, CA
- Average rainfall in January: 0.31"
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 January
San Mateo, CA
- Average rainfall days in January: 4.4 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 January /
Average sunshine in January
San Mateo, CA
- Average daylight in January: 9h and 5min
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 January: 6h 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 January
San Mateo, CA
- Average sunshine days in January: 25 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 January
San Mateo, CA
- Average UV index in January: 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 January
San Mateo, CA
- Average cloud cover in January: 32
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 January
San Mateo, CA
- Average visibility in January: 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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