December weather forecast
Greenfield, CA

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Weather in December

The first month of the winter, December, is also a moderate month in Greenfield, California, with an average temperature varying between 40.8°F (4.9°C) and 56.8°F (13.8°C).

Temperature

With average high and low temperatures of 56.8°F (13.8°C) and 40.8°F (4.9°C) respectively, December is Greenfield's coldest month.

Humidity

The average relative humidity in December is 68%.

Rainfall

The month with the most rainfall is December, when the rain falls for 9.2 days and typically aggregates up to 1.89" (48mm) of precipitation.

Daylight

December has the shortest days of the year in Greenfield, with an average of 9h and 42min of daylight.
On the first day of the month, sunrise is at 6:58 am and sunset at 4:50 pm. On the last day of December, sunrise is at 7:16 am and sunset at 5:00 pm PST.

Sunshine

The month with the least sunshine is December, with an average of 6.1h of sunshine.

UV index

February, November 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 moderate health risk from unprotected exposure to Sun's UV rays for average individuals.
Note: In December, the maximum UV index of 3 translates into these guidelines:
Put precautions into practice - Protective measures against sun-induced damage are advised. UV radiation from the Sun is most dangerous during midday; take precautions and seek shade. Sunglasses providing both UVA and UVB protection are non-negotiable on sunlit days.
Updated: Jul 15, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the coldest time of year?

December is the month that records the lowest temperatures, with averages ranging from a high of 56.8°F (13.8°C) to a low of 40.8°F (4.9°C).

What are December temperatures?

In Greenfield, in December, the average high-temperature is 56.8°F (13.8°C), and the average low-temperature is 40.8°F (4.9°C). In September, the average heat index (a.k.a. 'real feel', 'felt air temperature'), which represents the influence of relative humidity on air temperature, is evaluated at 86°F (30°C).

What is the average humidity in December?

In December, the average relative humidity is 68%.

What is the rainiest month?

The month with the most rainfall is December, when the rain falls for 9.2 days and typically aggregates up to 1.89" (48mm) of precipitation.

How much does it rain in December?

In December, the rain falls for 9.2 days. Throughout December, 1.89" (48mm) of precipitation is accumulated.

What is the month with the shortest days?

December has the shortest days of the year, with an average of 9h and 42min of daylight.

What is the average length of the day in December?

The average day length in December is 9h and 44min.

When are sunrise and sunset in December?

In December, on the first day of the month, sunrise is at 6:58 am and sunset at 4:50 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 5:00 pm PST.

What is the month with the least sunshine?

With an average of 6.1h of sunshine, December has the least sunshine of the year in Greenfield.

How many hours of sunshine does Greenfield have in December?

The average sunshine duration in December is 6.1h.

What is the month with the lowest UV index?

The months with the lowest UV index are February, November and December, with an average maximum UV index of 3.

What is the UV index reading in December?

In Greenfield, the average daily maximum UV index in December is 3. A UV Index estimate of 3 to 5 represents a moderate health threat from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Greenfield, CA

Average temperature in December - Greenfield, CA
  • Average high temperature in December: 56.8°F

The warmest month (with the highest average high temperature) is July (89.1°F).
The month with the lowest average high temperature is December (56.8°F).

  • Average low temperature in December: 40.8°F

The month with the highest average low temperature is August (58.6°F).
The coldest month (with the lowest average low temperature) is December (40.8°F).

Average pressure in December
Greenfield, CA

Average pressure in December - Greenfield, CA
  • Average pressure in December: 30.11"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
Greenfield, CA

Average wind speed in December - Greenfield, CA
  • Average wind speed in December: 4.7mph

The windiest month (with the highest average wind speed) is May (6.3mph).
The calmest month (with the lowest average wind speed) is November (4.5mph).

Average humidity in December
Greenfield, CA

Average humidity in December - Greenfield, CA
  • Average humidity in December: 68%

The month with the highest relative humidity is February (70%).
The month with the lowest relative humidity is July (46%).

Average rainfall in December
Greenfield, CA

Average rainfall in December - Greenfield, CA
  • Average rainfall in December: 1.89"

The wettest month (with the highest rainfall) is December (1.89").
The driest month (with the least rainfall) is August (0.04").

Average rainfall days in December
Greenfield, CA

Average rainfall days in December - Greenfield, CA
  • Average rainfall days in December: 9.2 days

The month with the highest number of rainy days is March (11.8 days).
The month with the least rainy days is August (0.4 days).

Average daylight in December /
Average sunshine in December
Greenfield, CA

Average daylight in December / Average sunshine in December - Greenfield, CA
  • Average daylight in December: 9h and 4min

The month with the longest days is June (Average daylight: 14h and 36min).
The month with the shortest days is December (Average daylight: 9h and 42min).

  • Average sunshine in December: 6h and 1min

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 6min).

Average sunshine days in December
Greenfield, CA

Average sunshine days in December - Greenfield, CA
  • Average sunshine days in December: 20.6 days

The month with the most sunshine days is August (30.1 days).
The month with the least sunshine days is March (18.3 days).

Average UV index in December
Greenfield, CA

Average UV index in December - Greenfield, 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 February, November and December (UV index 3).

Average cloud cover in December
Greenfield, CA

Average cloud cover in December - Greenfield, CA
  • Average cloud cover in December: 32

The months with the most cloud cover are March and December (Cloud cover 32).
The months with the least cloud cover are July and August (Cloud cover 4).

Average visibility in December
Greenfield, CA

Average visibility in December - Greenfield, 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).

Greenfield, California, USA

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