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
Atherton's shift from December to January is accompanied by an average high-temperature of a still refreshing 56.8°F (13.8°C), a slight deviation from 55.9°F (13.3°C). Throughout January nights, Atherton experiences a consistent temperature average of 46.4°F (8°C).Humidity
The average relative humidity in January is 73%.Rainfall
In January, the rain falls for 10.1 days. Throughout January, 1.93" (49mm) of precipitation is accumulated. Throughout the year, there are 73.4 rainfall days, and 11.89" (302mm) of precipitation is accumulated.Daylight
In January, the average length of the day is 9h and 56min.On the first day of the month, sunrise is at 7:23 am and sunset at 5:01 pm. On the last day of January, sunrise is at 7:12 am and sunset at 5:31 pm PST.
Sunshine
The average sunshine in January is 6.2h.UV index
In Atherton, California, the average daily maximum UV index in January is 4. A UV Index estimate of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for the ordinary person.Note: In January, the maximum UV index of 4 translates into these guidelines:
Take care. Persons with lighter skin might suffer burns in less than 30 minutes. Considering the harmful UV rays from the Sun during midday, it's essential to reduce exposure. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly.
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 long on average sun shines in January?
How high is the UV index in January?
Average temperature in January
Atherton, CA
- Average high temperature in January: 56.8°F
The warmest months (with the highest average high temperature) are July and August (73°F).
The month with the lowest average high temperature is December (55.9°F).
- Average low temperature in January: 46.4°F
The month with the highest average low temperature is September (56.7°F).
The coldest month (with the lowest average low temperature) is February (46°F).
Average pressure in January
Atherton, CA
- Average pressure in January: 30.13"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is September (29.92"Hg).
Average wind speed in January
Atherton, CA
- Average wind speed in January: 5.8mph
The windiest month (with the highest average wind speed) is April (7.5mph).
The calmest months (with the lowest average wind speed) are August, September and October (5.5mph).
Average humidity in January
Atherton, CA
- Average humidity in January: 73%
The month with the highest relative humidity is March (75%).
The month with the lowest relative humidity is October (68%).
Average rainfall in January
Atherton, CA
- Average rainfall in January: 1.93"
The wettest month (with the highest rainfall) is February (2.36").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in January
Atherton, CA
- Average rainfall days in January: 10.1 days
The month with the highest number of rainy days is March (12.8 days).
The month with the least rainy days is August (0.8 days).
Average daylight in January /
Average sunshine in January
Atherton, CA
- Average daylight in January: 9h and 5min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in January: 6h and 1min
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 48min).
Average sunshine days in January
Atherton, CA
- Average sunshine days in January: 19.8 days
The month with the most sunshine days is August (27.6 days).
The month with the least sunshine days is March (17.5 days).
Average UV index in January
Atherton, CA
- Average UV index in January: 4
The months with the highest UV index are June, July, August and September (UV index 5).
The months with the lowest UV index are November and December (UV index 3).
Average cloud cover in January
Atherton, CA
- Average cloud cover in January: 32
The month with the most cloud cover is March (Cloud cover 35).
The month with the least cloud cover is July (Cloud cover 9).
Average visibility in January
Atherton, 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).
Atherton, California, USA
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