January weather forecastRedwood City, CA

January
Weather in January
January, like December, is another mild winter month in Redwood City, California, with an average temperature ranging between min 46.4°F (8°C) and max 56.8°F (13.8°C).Temperature
The arrival of January brings an average high-temperature of a still mild 56.8°F (13.8°C), closely following the temperature pattern of December. Redwood City experiences a steady low-temperature of 46.4°F (8°C) throughout January.Humidity
The average relative humidity in January is 73%.Rainfall
In Redwood City, in January, it is raining for 10.1 days, with typically 1.93" (49mm) of accumulated precipitation. Throughout the year, there are 73.4 rainfall days, and 11.89" (302mm) of precipitation is accumulated.Ocean temperature
In January, the average ocean temperature is 54.1°F (12.3°C).Note: Swimming in 54.1°F (12.3°C) is considered dangerous. Unprotected immersion in temperatures below 50°F (10°C) causes quickly maximum intensity cold shock with hyperventilation.
Daylight
In January, the average length of the day is 9h and 56min.On the first day of January, sunrise is at 7:23 am and sunset at 5:01 pm. On the last day of the month, sunrise is at 7:13 am and sunset at 5:31 pm PST.
Sunshine
In January, the average sunshine is 6.2h.UV index
In January, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for average individuals.Note: The maximum daily UV index of 4 in January interprets into the following recommendations:
Ensure safety - Sun damage prevention is strongly urged. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in January
Redwood City, CA
- Average high temperature in January: 56.8°F
The warmest months (with the highest average high temperature) are July and August (73°F).
The month with the lowest average high temperature is December (55.9°F).
- Average low temperature in January: 46.4°F
The month with the highest average low temperature is September (56.7°F).
The coldest month (with the lowest average low temperature) is February (46°F).
Average pressure in January
Redwood City, 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
Redwood City, CA
- Average wind speed in January: 5.8mph
The windiest month (with the highest average wind speed) is April (7.5mph).
The calmest months (with the lowest average wind speed) are August, September and October (5.5mph).
Average humidity in January
Redwood City, CA
- Average humidity in January: 73%
The month with the highest relative humidity is March (75%).
The month with the lowest relative humidity is October (68%).
Average rainfall in January
Redwood City, CA
- Average rainfall in January: 1.93"
The wettest month (with the highest rainfall) is February (2.36").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in January
Redwood City, CA
- Average rainfall days in January: 10.1 days
The month with the highest number of rainy days is March (12.8 days).
The month with the least rainy days is August (0.8 days).
Average sea temperature in January
Redwood City, CA
- Average sea temperature in January: 54.1°F
The best months for swimming (with the highest average sea temperature) are August and September (57.7°F).
The coldest month (with the lowest average sea temperature) is April (53.4°F).
Average daylight in January /
Average sunshine in January
Redwood City, CA
- Average daylight in January: 9h and 54min
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 12min
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 48min).
Average sunshine days in January
Redwood City, CA
- Average sunshine days in January: 19.8 days
The month with the most sunshine days is August (27.6 days).
The month with the least sunshine days is March (17.5 days).
Average UV index in January
Redwood City, 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 November and December (UV index 3).
Average cloud cover in January
Redwood City, 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 9).
Average visibility in January
Redwood City, 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).





