Contents
- Weather in January
- Frequently asked questions
- Average temperature in January
- Average pressure in January
- Average wind speed in January
- Average humidity in January
- Average rainfall in January
- Average rainfall days in January
- Average daylight in January
- Average sunshine in January
- Average sunshine days in January
- Average UV index in January
- Average cloud cover in January
- Average visibility in January
Weather in January
Temperature
As January takes hold, the average high-temperature is a mild 56.5°F (13.6°C), nearly mirroring that of the previous month. Petaluma witnesses a consistent average low-temperature of 43.7°F (6.5°C) throughout January.Humidity
In Petaluma, the average relative humidity in January is 75%.Rainfall
In January, the rain falls for 9.5 days. Throughout January, 2.64" (67mm) of precipitation is accumulated. In Petaluma, California, during the entire year, the rain falls for 71.1 days and collects up to 15.24" (387mm) of precipitation.Daylight
In January, the average length of the day in Petaluma, California, is 9h and 52min.On the first day of January in Petaluma, sunrise is at 7:27 am and sunset at 5:00 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 5:31 pm PST.
Sunshine
In Petaluma, the average sunshine in January is 5.8h.UV index
January, February, November and December, with an average maximum UV index of 3, are months with the lowest UV index in Petaluma. A UV Index of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for the average person.Note: A maximum daily UV index of 3 during January morphs into the following directions:
Undertake protective steps - Preventing sun damage is advised. The Sun is at its harshest during midday; protect yourself by staying in shaded areas and minimizing exposure. Sunglasses providing both UVA and UVB protection are non-negotiable on sunlit days.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average January temperature in Petaluma?
What is the average humidity in January in Petaluma?
How many days does it rain in January in Petaluma?
What is the average length of the day in January in Petaluma?
What time are sunrise and sunset in January in Petaluma?
How long on average sun shines in January in Petaluma?
When is the lowest UV index in Petaluma?
What is the UV index reading in January in Petaluma?
Average temperature in January
Petaluma, CA
- Average high temperature in January: 56.5°F
The warmest month (with the highest average high temperature) is August (77.9°F).
The month with the lowest average high temperature is December (55.2°F).
- Average low temperature in January: 43.7°F
The month with the highest average low temperature is September (55.2°F).
The coldest month (with the lowest average low temperature) is December (43.2°F).
Average pressure in January
Petaluma, 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
Petaluma, CA
- Average wind speed in January: 5.3mph
The windiest months (with the highest average wind speed) are April and May (7mph).
The calmest month (with the lowest average wind speed) is November (5mph).
Average humidity in January
Petaluma, CA
- Average humidity in January: 75%
The month with the highest relative humidity is March (77%).
The months with the lowest relative humidity are September and October (65%).
Average rainfall in January
Petaluma, CA
- Average rainfall in January: 2.64"
The wettest month (with the highest rainfall) is February (3.5").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in January
Petaluma, CA
- Average rainfall days in January: 9.5 days
The month with the highest number of rainy days is March (12.6 days).
The month with the least rainy days is July (1 days).
Average daylight in January /
Average sunshine in January
Petaluma, CA
- Average daylight in January: 9h and 5min
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 5min
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 42min).
Average sunshine days in January
Petaluma, CA
- Average sunshine days in January: 20.3 days
The month with the most sunshine days is July (28.4 days).
The month with the least sunshine days is March (17.2 days).
Average UV index in January
Petaluma, 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
Petaluma, CA
- Average cloud cover in January: 35
The month with the most cloud cover is March (Cloud cover 39).
The month with the least cloud cover is July (Cloud cover 10).
Average visibility in January
Petaluma, 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).
Petaluma, California, USA
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