January weather forecastGuerneville, CA
January
Weather in January
January, the same as December, in Guerneville, California, is another refreshing winter month, with temperature in the range of an average low of 42.3°F (5.7°C) and an average high of 57.7°F (14.3°C).Temperature
The average high-temperature during January is a still refreshing 57.7°F (14.3°C), almost matching the conditions of the preceding month. In the month of January, Guerneville's average low-temperature falls to an icy 42.3°F (5.7°C).Humidity
In January, the average relative humidity in Guerneville, California, is 75%.Rainfall
In Guerneville, California, during January, the rain falls for 8.1 days and regularly aggregates up to 1.97" (50mm) of precipitation. In Guerneville, during the entire year, the rain falls for 60.1 days and collects up to 12.87" (327mm) of precipitation.Daylight
In January, the average length of the day is 9h and 51min.On the first day of the month, sunrise is at 7:29 am and sunset at 5:01 pm. On the last day of January, sunrise is at 7:18 am and sunset at 5:32 pm PST.
Sunshine
The average sunshine in January in Guerneville is 5.6h.UV index
The months with the lowest UV index in Guerneville, California, are January, February, November and December, with an average maximum UV index of 3. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV radiation for average individuals.Note: The UV index of 3 during January leads to these advisories:
Be vigilant - A duty to shield skin and eyes from injury exists. Stay safe from the Sun's strongest UV rays by limiting exposure during midday. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in January
Guerneville, CA
- Average high temperature in January: 57.7°F
The warmest month (with the highest average high temperature) is August (81°F).
The month with the lowest average high temperature is December (56.3°F).
- Average low temperature in January: 42.3°F
The months with the highest average low temperature are August and September (53.4°F).
The coldest month (with the lowest average low temperature) is December (41.4°F).
Average pressure in January
Guerneville, CA
- Average pressure in January: 30.13"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.92"Hg).
Average wind speed in January
Guerneville, CA
- Average wind speed in January: 5.3mph
The windiest month (with the highest average wind speed) is May (7.2mph).
The calmest month (with the lowest average wind speed) is November (5mph).
Average humidity in January
Guerneville, CA
- Average humidity in January: 75%
The month with the highest relative humidity is March (77%).
The month with the lowest relative humidity is September (62%).
Average rainfall in January
Guerneville, CA
- Average rainfall in January: 1.97"
The wettest month (with the highest rainfall) is February (3.27").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in January
Guerneville, CA
- Average rainfall days in January: 8.1 days
The month with the highest number of rainy days is March (10.3 days).
The month with the least rainy days is August (0.9 days).
Average daylight in January /
Average sunshine in January
Guerneville, CA
- Average daylight in January: 9h and 48min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in January: 5h and 36min
The month with the most sunshine is July (Average sunshine: 11h and 48min).
The month with the least sunshine is December (Average sunshine: 5h and 24min).
Average sunshine days in January
Guerneville, CA
- Average sunshine days in January: 22 days
The month with the most sunshine days is July (28.9 days).
The month with the least sunshine days is February (19.9 days).
Average UV index in January
Guerneville, CA
- Average UV index in January: 3
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in January
Guerneville, CA
- Average cloud cover in January: 38
The month with the most cloud cover is March (Cloud cover 42).
The month with the least cloud cover is July (Cloud cover 11).
Average visibility in January
Guerneville, 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).





