December weather forecastGilroy, CA
December
Weather in December
The first month of the winter, December, is still a refreshing month in Gilroy, California, with an average temperature varying between 57.6°F (14.2°C) and 41.2°F (5.1°C).Temperature
With its high average temperature of 57.6°F (14.2°C) and a low of 41.2°F (5.1°C), December is regarded as the coldest month.Humidity
In December, the average relative humidity is 71%.Rainfall
The month with the most rainfall is December, when the rain falls for 6.6 days and typically aggregates up to 0.83" (21mm) of precipitation.Daylight
With an average of 9h and 42min of daylight, December has the shortest days of the year.On the first day of December, sunrise is at 7:01 am and sunset at 4:49 pm. On the last day of the month, sunrise is at 7:19 am and sunset at 4:59 pm PST.
Sunshine
With an average of 6h of sunshine, December has the least sunshine of the year.UV index
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 3. 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: A maximum high UV index of 3 in December translates into the following recommendations:
Take precautions - Protection against skin and eye damage is obliged. Minimize direct exposure to the Sun during midday when its radiation is at its peak. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Gilroy, CA
- Average high temperature in December: 57.6°F
The warmest month (with the highest average high temperature) is August (85.1°F).
The month with the lowest average high temperature is December (57.6°F).
- Average low temperature in December: 41.2°F
The months with the highest average low temperature are August and September (54.1°F).
The coldest months (with the lowest average low temperature) are February and March (40.6°F).
Average pressure in December
Gilroy, CA
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.92"Hg).
Average wind speed in December
Gilroy, CA
- Average wind speed in December: 4.1mph
The windiest month (with the highest average wind speed) is May (5.3mph).
The calmest month (with the lowest average wind speed) is November (3.9mph).
Average humidity in December
Gilroy, CA
- Average humidity in December: 71%
The month with the highest relative humidity is March (74%).
The month with the lowest relative humidity is September (57%).
Average rainfall in December
Gilroy, CA
- Average rainfall in December: 0.83"
The wettest month (with the highest rainfall) is December (0.83").
The driest months (with the least rainfall) are June, July and August (0").
Average rainfall days in December
Gilroy, CA
- Average rainfall days in December: 6.6 days
The month with the highest number of rainy days is March (8.3 days).
The month with the least rainy days is August (0.6 days).
Average daylight in December /
Average sunshine in December
Gilroy, CA
- Average daylight in December: 9h and 42min
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 42min).
- 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
Gilroy, CA
- Average sunshine days in December: 23.2 days
The month with the most sunshine days is July (29.9 days).
The month with the least sunshine days is March (21.4 days).
Average UV index in December
Gilroy, CA
- Average UV index in December: 3
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in December
Gilroy, CA
- Average cloud cover in December: 34
The month with the most cloud cover is March (Cloud cover 35).
The month with the least cloud cover is July (Cloud cover 7).
Average visibility in December
Gilroy, 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).
