January weather forecastNapa Junction, CA
January
Weather in January
January in Napa Junction, California, is a mild winter month, with temperature in the range of an average high of 56.3°F (13.5°C) and an average low of 42.3°F (5.7°C).Temperature
The arrival of January sees a recorded average high-temperature of a mild 56.3°F (13.5°C), showing little divergence from the previous month's conditions. In January, Napa Junction encounters an average low-temperature of 42.3°F (5.7°C) during the night.Humidity
In Napa Junction, the average relative humidity in January is 73%.Rainfall
In Napa Junction, in January, it is raining for 9 days, with typically 2.2" (56mm) of accumulated precipitation. Throughout the year, there are 68.2 rainfall days, and 11.93" (303mm) of precipitation is accumulated.Daylight
In January, the average length of the day in Napa Junction is 9h and 52min.On the first day of January, sunrise is at 7:25 am and sunset at 4:59 pm. On the last day of the month, sunrise is at 7:14 am and sunset at 5:30 pm PST.
Sunshine
In Napa Junction, the average sunshine in January is 5.9h.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 of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV rays for the average person.Note: In January, the maximum UV index of 3 translates into these guidelines:
Be mindful. Those with pale skin might receive burns in fewer than 30 minutes. The Sun's UV radiation is especially harmful around midday, so reduce exposure and stay safe. 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
Napa Junction, CA
- Average high temperature in January: 56.3°F
The warmest month (with the highest average high temperature) is July (82.6°F).
The month with the lowest average high temperature is December (54.9°F).
- Average low temperature in January: 42.3°F
The month with the highest average low temperature is August (56.5°F).
The coldest months (with the lowest average low temperature) are January and December (42.3°F).
Average pressure in January
Napa Junction, CA
- Average pressure in January: 30.14"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in January
Napa Junction, CA
- Average wind speed in January: 4.7mph
The windiest month (with the highest average wind speed) is May (6.6mph).
The calmest month (with the lowest average wind speed) is November (4.5mph).
Average humidity in January
Napa Junction, CA
- Average humidity in January: 73%
The month with the highest relative humidity is March (75%).
The month with the lowest relative humidity is September (58%).
Average rainfall in January
Napa Junction, CA
- Average rainfall in January: 2.2"
The wettest month (with the highest rainfall) is February (2.32").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in January
Napa Junction, CA
- Average rainfall days in January: 9 days
The month with the highest number of rainy days is March (11.9 days).
The month with the least rainy days is August (0.9 days).
Average daylight in January /
Average sunshine in January
Napa Junction, CA
- Average daylight in January: 9h and 54min
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 36min).
- Average sunshine in January: 5h and 54min
The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 42min).
Average sunshine days in January
Napa Junction, CA
- Average sunshine days in January: 21.3 days
The months with the most sunshine days are July and August (29.1 days).
The month with the least sunshine days is March (18.3 days).
Average UV index in January
Napa Junction, 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
Napa Junction, CA
- Average cloud cover in January: 35
The month with the most cloud cover is March (Cloud cover 37).
The month with the least cloud cover is July (Cloud cover 7).
Average visibility in January
Napa Junction, 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).
