January weather forecastPort Costa, CA
January
Weather in January
January, the same as December, in Port Costa, California, is a moderate winter month, with an average temperature ranging between max 56.5°F (13.6°C) and min 43°F (6.1°C).Temperature
With the advent of January, Port Costa's high-temperatures adjust to a still refreshing 56.5°F (13.6°C), closely aligning with the preceding month. Nighttime temperatures in January average to a frosty 43°F (6.1°C).Humidity
The average relative humidity in January is 73%.Rainfall
In Port Costa, during January, the rain falls for 7.7 days and regularly aggregates up to 0.83" (21mm) of precipitation. Throughout the year, there are 56.9 rainfall days, and 4.88" (124mm) of precipitation is accumulated.Daylight
In January, the average length of the day is 9h and 53min.On the first day of the month, sunrise is at 7:24 am and sunset at 4:59 pm. On the last day of January, sunrise is at 7:14 am and sunset at 5:30 pm PST.
Sunshine
In Port Costa, 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 unprotected exposure to Sun's UV rays for ordinary individuals.Note: The maximum UV index of 3 during January leads to these instructions:
Act with care - The need to guard against sun damage is communicated. UV radiation from the Sun is most dangerous during midday; take precautions and seek shade. During bright days, sunglasses that offer UVA and UVB defense are recommended.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in January
Port Costa, CA
- Average high temperature in January: 56.5°F
The warmest months (with the highest average high temperature) are July and September (80.1°F).
The month with the lowest average high temperature is December (55.4°F).
- Average low temperature in January: 43°F
The month with the highest average low temperature is August (56.5°F).
The coldest month (with the lowest average low temperature) is January (43°F).
Average pressure in January
Port Costa, 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
Port Costa, CA
- Average wind speed in January: 4.9mph
The windiest month (with the highest average wind speed) is May (7.1mph).
The calmest month (with the lowest average wind speed) is November (4.6mph).
Average humidity in January
Port Costa, CA
- Average humidity in January: 73%
The month with the highest relative humidity is March (75%).
The months with the lowest relative humidity are September and October (60%).
Average rainfall in January
Port Costa, CA
- Average rainfall in January: 0.83"
The wettest month (with the highest rainfall) is February (1.14").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in January
Port Costa, CA
- Average rainfall days in January: 7.7 days
The month with the highest number of rainy days is March (10.2 days).
The month with the least rainy days is August (0.9 days).
Average daylight in January /
Average sunshine in January
Port Costa, 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 month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 42min).
Average sunshine days in January
Port Costa, CA
- Average sunshine days in January: 21.8 days
The month with the most sunshine days is July (27.2 days).
The month with the least sunshine days is March (18.8 days).
Average UV index in January
Port Costa, CA
- Average UV index in January: 3
The month with the highest UV index is June (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in January
Port Costa, 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 9).
Average visibility in January
Port Costa, 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).
