Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average snowfall days in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
December, known for its average high temperature of 63.1°F (17.3°C) and an average low temperature of 47.3°F (8.5°C), is the coldest month.Humidity
The average relative humidity in December in Irwindale is 51%.Rainfall
In December, in Irwindale, California, the rain falls for 5.9 days. Throughout December, 1.69" (43mm) of precipitation is accumulated. In Irwindale, during the entire year, the rain falls for 49.6 days and collects up to 8.11" (206mm) of precipitation.Snowfall
The only month with snowfall in Irwindale is December. The month with the most snowfall days in Irwindale is December, when snow falls for 0.1 days.Daylight
December has the shortest days of the year, with an average of 9h and 54min of daylight.On the first day of the month, sunrise is at 6:39 am and sunset at 4:42 pm. On the last day of December, sunrise is at 6:57 am and sunset at 4:52 pm PST.
Sunshine
January, February and December, with an average of 6.9h of sunshine, are months with the least sunshine in Irwindale.UV index
The months with the lowest UV index are January through March, November and December, with an average maximum UV index of 4. A UV Index reading of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV rays for the ordinary person.Note: During December, 4 as the daily maximum UV index converts into the following advice:
Exercise prudence. Persons with fair skin could be burned in under 30 minutes. Midday is the peak time for the Sun's radiation; stay in the shade and protect yourself. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation. Be watchful! The reflection of snow can enhance the intensity of the Sun's UV radiation nearly double.
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Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the coldest months in Irwindale?
What is the average December temperature in Irwindale?
What is the average humidity in December in Irwindale?
How much does it rain in Irwindale in December?
When does it snow the most in Irwindale?
When does it start snowing in Irwindale?
What is the month with the shortest days in Irwindale?
How many hours of daylight does Irwindale have in December?
When are sunrise and sunset in December in Irwindale?
What are the months with the least sunshine in Irwindale?
How long on average sun shines in December in Irwindale?
What is the month with the lowest UV index in Irwindale?
What is the UV index reading in December in Irwindale?
Average temperature in December
Irwindale, CA
- Average high temperature in December: 63.1°F
The warmest month (with the highest average high temperature) is August (87.1°F).
The month with the lowest average high temperature is December (63.1°F).
- Average low temperature in December: 47.3°F
The month with the highest average low temperature is August (64.9°F).
The coldest months (with the lowest average low temperature) are February and December (47.3°F).
Average pressure in December
Irwindale, CA
- Average pressure in December: 30.08"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in December
Irwindale, CA
- Average wind speed in December: 5.1mph
The windiest months (with the highest average wind speed) are April and May (5.7mph).
The calmest month (with the lowest average wind speed) is September (4.4mph).
Average humidity in December
Irwindale, CA
- Average humidity in December: 51%
The months with the highest relative humidity are May and June (57%).
The month with the lowest relative humidity is November (46%).
Average rainfall in December
Irwindale, CA
- Average rainfall in December: 1.69"
The wettest month (with the highest rainfall) is February (1.73").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in December
Irwindale, CA
- Average rainfall days in December: 5.9 days
The month with the highest number of rainy days is March (6.5 days).
The month with the least rainy days is June (1.2 days).
Average snowfall days in December
Irwindale, CA
- Average snowfall days in December: 0.1 days
The month with the highest number of snowfall days is December (0.1 days).
The months with the least snowfall days are January, February, March, April, May, June, July, August, September, October and November (0 days).
Average daylight in December /
Average sunshine in December
Irwindale, CA
- Average daylight in December: 9h and 5min
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 December: 6h and 5min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The months with the least sunshine are January, February and December (Average sunshine: 6h and 54min).
Average sunshine days in December
Irwindale, CA
- Average sunshine days in December: 24.1 days
The month with the most sunshine days is June (28.3 days).
The month with the least sunshine days is February (21.5 days).
Average UV index in December
Irwindale, CA
- Average UV index in December: 4
The months with the highest UV index are June, July, August and September (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 4).
Average cloud cover in December
Irwindale, CA
- Average cloud cover in December: 22
The months with the most cloud cover are March and December (Cloud cover 22).
The month with the least cloud cover is August (Cloud cover 5).
Average visibility in December
Irwindale, 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).
Irwindale, California, USA
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