January weather forecastSaint Helena, CA
January
Weather in January
January is a refreshing winter month in Saint Helena, California, with an average temperature fluctuating between 39.7°F (4.3°C) and 56.8°F (13.8°C).Temperature
The average high-temperature during January is a mild 56.8°F (13.8°C), almost matching the conditions of the preceding month. Throughout January, Saint Helena experiences a low-temperature average of 39.7°F (4.3°C).Humidity
The average relative humidity in January is 74%.Rainfall
In Saint Helena, during January, the rain falls for 10.2 days and regularly aggregates up to 3.15" (80mm) of precipitation. In Saint Helena, California, during the entire year, the rain falls for 76.2 days and collects up to 16.93" (430mm) of precipitation.Snowfall
January, February, April through December are months without snowfall.Daylight
The average length of the day in January is 9h and 51min.On the first day of January, sunrise is at 7:27 am and sunset at 4:59 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 5:30 pm PST.
Sunshine
The average sunshine in January is 5.4h.UV index
January, February, November and December, with an average maximum UV index of 3, are months with the lowest UV index. A UV Index value of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for the ordinary person.Note: In January, the average maximum UV index of 3 translates into the following recommendations:
Take necessary precautions - Protection from skin and eye injury is mandatory. Around midday, solar radiation is most harmful; hence, exposure should be limited. Stay sun-safe with clothing that is both closely woven and worn loosely.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in January
Saint Helena, CA
- Average high temperature in January: 56.8°F
The warmest month (with the highest average high temperature) is July (88.3°F).
The month with the lowest average high temperature is December (54.5°F).
- Average low temperature in January: 39.7°F
The month with the highest average low temperature is September (54.3°F).
The coldest month (with the lowest average low temperature) is December (39.6°F).
Average pressure in January
Saint Helena, CA
- Average pressure in January: 30.14"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.91"Hg).
Average wind speed in January
Saint Helena, CA
- Average wind speed in January: 4.5mph
The windiest month (with the highest average wind speed) is May (5.8mph).
The calmest month (with the lowest average wind speed) is November (4.3mph).
Average humidity in January
Saint Helena, CA
- Average humidity in January: 74%
The month with the highest relative humidity is March (76%).
The month with the lowest relative humidity is September (53%).
Average rainfall in January
Saint Helena, CA
- Average rainfall in January: 3.15"
The wettest month (with the highest rainfall) is February (3.7").
The driest month (with the least rainfall) is July (0").
Average rainfall days in January
Saint Helena, CA
- Average rainfall days in January: 10.2 days
The month with the highest number of rainy days is March (13.5 days).
The month with the least rainy days is August (0.3 days).
Average snowfall in January
Saint Helena, CA
- Average snowfall in January: 0"
The month with the highest snowfall is March (0.04").
The months with the least snowfall are January, February, April, May, June, July, August, September, October, November and December (0").
Average snowfall days in January
Saint Helena, CA
- Average snowfall days in January: 0 days
The month with the highest number of snowfall days is March (0.2 days).
The months with the least snowfall days are January, February, April, May, June, July, August, September, October, November and December (0 days).
Average daylight in January /
Average sunshine in January
Saint Helena, 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 24min
The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is December (Average sunshine: 5h and 18min).
Average sunshine days in January
Saint Helena, CA
- Average sunshine days in January: 19.9 days
The month with the most sunshine days is July (30 days).
The month with the least sunshine days is March (15.9 days).
Average UV index in January
Saint Helena, 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
Saint Helena, CA
- Average cloud cover in January: 41
The month with the most cloud cover is March (Cloud cover 44).
The month with the least cloud cover is July (Cloud cover 7).
Average visibility in January
Saint Helena, CA
- Average visibility in January: 5mi
The months with the highest visibility are February, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January and March (5mi).
