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 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 is the coldest month, with an average high-temperature of 55.6°F (13.1°C) and an average low-temperature of 47.8°F (8.8°C).Humidity
In December, the average relative humidity in Hillsborough is 72%.Rainfall
In December, the rain falls for 11.1 days. Throughout December, 2.17" (55mm) of precipitation is accumulated. In Hillsborough, during the entire year, the rain falls for 81.5 days and collects up to 12.8" (325mm) of precipitation.Daylight
With an average of 9h and 36min of daylight, December has the shortest days of the year.On the first day of the month, sunrise is at 7:06 am and sunset at 4:51 pm. On the last day of December, in Hillsborough, California, sunrise is at 7:24 am and sunset at 5:01 pm PST.
Sunshine
With an average of 5.8h of sunshine, December has the least sunshine of the year in Hillsborough.UV index
February and December, with an average maximum UV index of 3, are months with the lowest UV index. A UV Index of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV radiation for the average person.Note: A maximum high UV index of 3 in December translates into the following recommendations:
Heed the precautions - It is counselled to guard against solar damage. The Sun's radiation is especially intense around midday; try to stay in shade during this period. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation.
Frequently asked questions
What are the coldest months in Hillsborough?
What are the temperatures in Hillsborough in December?
What is the average humidity in December in Hillsborough?
How many days does it rain in December in Hillsborough?
What is the month with the shortest days in Hillsborough?
How many hours of daylight does Hillsborough have in December?
When is the sunrise / sunset in December in Hillsborough?
What is the month with the least sunshine in Hillsborough?
How many hours of sunshine does Hillsborough have in December?
When is the lowest UV index in Hillsborough?
What is the UV index reading in December in Hillsborough?
Average temperature in December
Hillsborough, CA
- Average high temperature in December: 55.6°F
The warmest month (with the highest average high temperature) is September (70.2°F).
The month with the lowest average high temperature is December (55.6°F).
- Average low temperature in December: 47.8°F
The month with the highest average low temperature is September (56.8°F).
The coldest month (with the lowest average low temperature) is January (47.5°F).
Average pressure in December
Hillsborough, CA
- Average pressure in December: 30.11"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 December
Hillsborough, CA
- Average wind speed in December: 7.2mph
The windiest month (with the highest average wind speed) is April (8.3mph).
The calmest month (with the lowest average wind speed) is September (6.1mph).
Average humidity in December
Hillsborough, CA
- Average humidity in December: 72%
The month with the highest relative humidity is August (78%).
The month with the lowest relative humidity is October (70%).
Average rainfall in December
Hillsborough, CA
- Average rainfall in December: 2.17"
The wettest month (with the highest rainfall) is February (2.44").
The driest month (with the least rainfall) is July (0.08").
Average rainfall days in December
Hillsborough, CA
- Average rainfall days in December: 11.1 days
The month with the highest number of rainy days is March (12.8 days).
The months with the least rainy days are June and July (2.4 days).
Average daylight in December /
Average sunshine in December
Hillsborough, CA
- Average daylight in December: 9h and 4min
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: 5h and 5min
The month with the most sunshine is July (Average sunshine: 11h and 48min).
The month with the least sunshine is December (Average sunshine: 5h and 48min).
Average sunshine days in December
Hillsborough, CA
- Average sunshine days in December: 19.1 days
The month with the most sunshine days is July (24.6 days).
The month with the least sunshine days is March (16.3 days).
Average UV index in December
Hillsborough, CA
- Average UV index in December: 3
The months with the highest UV index are June, July, August and September (UV index 5).
The months with the lowest UV index are February and December (UV index 3).
Average cloud cover in December
Hillsborough, CA
- Average cloud cover in December: 35
The month with the most cloud cover is March (Cloud cover 36).
The months with the least cloud cover are July and September (Cloud cover 15).
Average visibility in December
Hillsborough, 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).
Hillsborough, California, USA
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