December weather forecastBystrom, CA
December
Weather in December
December, the first month of the winter in Bystrom, is still a refreshing month, with an average temperature fluctuating between 41.9°F (5.5°C) and 55.6°F (13.1°C).Temperature
With its high average temperature of 55.6°F (13.1°C) and a low of 41.9°F (5.5°C), December is regarded as the coldest month.Humidity
The average relative humidity in December in Bystrom is 70%.Rainfall
In December, the rain falls for 8.2 days. Throughout December, 1.22" (31mm) of precipitation is accumulated. In Bystrom, during the entire year, the rain falls for 54.3 days and collects up to 6.54" (166mm) of precipitation.Daylight
December has the shortest days of the year in Bystrom, with an average of 9h and 36min of daylight.On the first day of the month, sunrise is at 7:00 am and sunset at 4:45 pm. On the last day of December, sunrise is at 7:18 am and sunset at 4:55 pm PST.
Sunshine
With an average of 6h of sunshine, December has the least sunshine of the year in Bystrom.UV index
January, February, November and December, with an average maximum UV index of 3, are months with the lowest UV index in Bystrom. A UV Index reading of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for average individuals.Note: The maximum UV index of 3 during December leads to these instructions:
Take precautions - Protection against sun damage is advised. Considering the Sun's intensity during midday, it's wise to minimize direct exposure. Equip yourself with UVA and UVB-filtering sunglasses on clear, sunny days.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Bystrom, CA
- Average high temperature in December: 55.6°F
The warmest month (with the highest average high temperature) is July (97.7°F).
The month with the lowest average high temperature is December (55.6°F).
- Average low temperature in December: 41.9°F
The month with the highest average low temperature is July (62.1°F).
The coldest months (with the lowest average low temperature) are January and December (41.9°F).
Average pressure in December
Bystrom, CA
- Average pressure in December: 30.12"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in December
Bystrom, CA
- Average wind speed in December: 5.7mph
The windiest month (with the highest average wind speed) is June (7.3mph).
The calmest month (with the lowest average wind speed) is November (5.2mph).
Average humidity in December
Bystrom, CA
- Average humidity in December: 70%
The month with the highest relative humidity is January (72%).
The month with the lowest relative humidity is July (37%).
Average rainfall in December
Bystrom, CA
- Average rainfall in December: 1.22"
The wettest month (with the highest rainfall) is March (1.3").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in December
Bystrom, CA
- Average rainfall days in December: 8.2 days
The month with the highest number of rainy days is March (10.3 days).
The month with the least rainy days is August (0.9 days).
Average daylight in December /
Average sunshine in December
Bystrom, CA
- Average daylight in December: 9h and 36min
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 December: 6h and 0min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 0min).
Average sunshine days in December
Bystrom, CA
- Average sunshine days in December: 22 days
The month with the most sunshine days is August (29.2 days).
The month with the least sunshine days is March (19.6 days).
Average UV index in December
Bystrom, CA
- Average UV index in December: 3
The months with the highest UV index are June, July and August (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in December
Bystrom, CA
- Average cloud cover in December: 32
The month with the most cloud cover is March (Cloud cover 33).
The month with the least cloud cover is July (Cloud cover 4).
Average visibility in December
Bystrom, CA
- Average visibility in December: 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).





