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, on average, is the coldest month, registering a high temperature of 55.4°F (13°C) and a low of 45.3°F (7.4°C).Humidity
In Mill Valley, the average relative humidity in December is 73%.Rainfall
In Mill Valley, in December, it is raining for 7.2 days, with typically 0.67" (17mm) of accumulated precipitation. Throughout the year, in Mill Valley, there are 48 rainfall days, and 3.94" (100mm) of precipitation is accumulated.Daylight
With an average of 9h and 36min of daylight, December has the shortest days of the year in Mill Valley.On the first day of December, sunrise is at 7:07 am and sunset at 4:51 pm. On the last day of the month, sunrise is at 7:25 am and sunset at 5:01 pm PST.
Sunshine
December has the least sunshine of the year, with an average of 5.5h of sunshine.UV index
January, February, November and December, with an average maximum UV index of 3, are months with the lowest UV index. A UV Index estimate of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for the average person.Note: In December, the maximum UV index of 3 transforms into these recommendations:
Take precautions - Protection against skin and eye damage is obliged. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. Experience reduced UV exposure by about half when donning a wide-brim hat.
Frequently asked questions
What is the coldest month in Mill Valley?
What is the average December temperature in Mill Valley?
What is the average humidity in December in Mill Valley?
How many days does it rain in December in Mill Valley?
What is the month with the shortest days in Mill Valley?
How many hours of daylight does Mill Valley have in December?
What time are sunrise and sunset in December in Mill Valley?
What is the month with the least sunshine in Mill Valley?
How long on average sun shines in December in Mill Valley?
What is the month with the lowest UV index in Mill Valley?
What is the UV index intensity in December in Mill Valley?
Average temperature in December
Mill Valley, CA
- Average high temperature in December: 55.4°F
The warmest month (with the highest average high temperature) is September (72.3°F).
The month with the lowest average high temperature is December (55.4°F).
- Average low temperature in December: 45.3°F
The month with the highest average low temperature is September (56.1°F).
The coldest month (with the lowest average low temperature) is December (45.3°F).
Average pressure in December
Mill Valley, CA
- Average pressure in December: 30.1"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.92"Hg).
Average wind speed in December
Mill Valley, CA
- Average wind speed in December: 6.2mph
The windiest month (with the highest average wind speed) is May (7.8mph).
The calmest months (with the lowest average wind speed) are October and November (5.5mph).
Average humidity in December
Mill Valley, CA
- Average humidity in December: 73%
The month with the highest relative humidity is March (77%).
The month with the lowest relative humidity is October (68%).
Average rainfall in December
Mill Valley, CA
- Average rainfall in December: 0.67"
The wettest month (with the highest rainfall) is February (0.87").
The driest months (with the least rainfall) are June, July, August and September (0.04").
Average rainfall days in December
Mill Valley, CA
- Average rainfall days in December: 7.2 days
The month with the highest number of rainy days is March (8.8 days).
The months with the least rainy days are June and August (1.2 days).
Average daylight in December /
Average sunshine in December
Mill Valley, CA
- Average daylight in December: 9h and 4min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in December: 5h and 3min
The month with the most sunshine is July (Average sunshine: 11h and 12min).
The month with the least sunshine is December (Average sunshine: 5h and 30min).
Average sunshine days in December
Mill Valley, CA
- Average sunshine days in December: 22.1 days
The month with the most sunshine days is June (26.4 days).
The month with the least sunshine days is March (20.7 days).
Average UV index in December
Mill Valley, CA
- Average UV index in December: 3
The months with the highest UV index are April, June, July, August and September (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in December
Mill Valley, CA
- Average cloud cover in December: 38
The month with the most cloud cover is March (Cloud cover 39).
The month with the least cloud cover is September (Cloud cover 19).
Average visibility in December
Mill Valley, 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).
Mill Valley, California, USA
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