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
December's transformation into January witnesses an average high-temperature of a still refreshing 62.8°F (17.1°C), noting a minor change from the preceding month. Altadena records an average low of 46.4°F (8°C) throughout the nights in January.Humidity
The average relative humidity in January is 51%.Rainfall
In Altadena, California, during January, the rain falls for 5.7 days and regularly aggregates up to 1.5" (38mm) of precipitation. Throughout the year, there are 52 rainfall days, and 8.82" (224mm) of precipitation is accumulated.Daylight
In Altadena, California, the average length of the day in January is 10h and 11min.On the first day of the month, sunrise is at 6:58 am and sunset at 4:53 pm. On the last day of January, in Altadena, California, sunrise is at 6:50 am and sunset at 5:21 pm PST.
Sunshine
In January, the average sunshine is 7h.UV index
In Altadena, the average daily maximum UV index in January is 4. A UV Index estimate of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for the ordinary person.Note: In January, a daily UV index of 4 turns into the following recommendations:
Make use of precautions - Shielding skin and eyes from injury is a requirement. Limiting exposure to the direct Sun during midday hours can help prevent harmful UV radiation effects. 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
What is the average January temperature?
What is the average humidity in January?
How much does it rain in January?
What is the average length of the day in January?
When is the sunrise / sunset in January?
How many hours of sunshine does Altadena have in January?
How high is the UV index in January?
Average temperature in January
Altadena, CA
- Average high temperature in January: 62.8°F
The warmest month (with the highest average high temperature) is August (86.2°F).
The month with the lowest average high temperature is December (61°F).
- Average low temperature in January: 46.4°F
The month with the highest average low temperature is August (64.4°F).
The coldest month (with the lowest average low temperature) is December (45.5°F).
Average pressure in January
Altadena, CA
- Average pressure in January: 30.11"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in January
Altadena, CA
- Average wind speed in January: 5.5mph
The windiest month (with the highest average wind speed) is April (5.8mph).
The calmest month (with the lowest average wind speed) is September (4.4mph).
Average humidity in January
Altadena, CA
- Average humidity in January: 51%
The months with the highest relative humidity are March, May and June (56%).
The month with the lowest relative humidity is November (46%).
Average rainfall in January
Altadena, CA
- Average rainfall in January: 1.5"
The wettest month (with the highest rainfall) is February (1.81").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in January
Altadena, CA
- Average rainfall days in January: 5.7 days
The month with the highest number of rainy days is March (7.5 days).
The month with the least rainy days is June (1.3 days).
Average daylight in January /
Average sunshine in January
Altadena, CA
- Average daylight in January: 10h and 1min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in January: 7h and 0min
The months with the most sunshine are June and July (Average sunshine: 12h and 6min).
The months with the least sunshine are February and December (Average sunshine: 6h and 54min).
Average sunshine days in January
Altadena, CA
- Average sunshine days in January: 24.5 days
The month with the most sunshine days is June (27.2 days).
The month with the least sunshine days is February (21.3 days).
Average UV index in January
Altadena, CA
- Average UV index in January: 4
The months with the highest UV index are June, July, August and September (UV index 6).
The month with the lowest UV index is December (UV index 3).
Average cloud cover in January
Altadena, CA
- Average cloud cover in January: 20
The month with the most cloud cover is March (Cloud cover 22).
The month with the least cloud cover is August (Cloud cover 5).
Average visibility in January
Altadena, 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).
Altadena, California, USA
Weather forecast for your location
2. Allow the app to use your location