December weather forecast
Grimes, CA

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Weather in December

The first month of the winter, December, is still a cool month in Grimes, California, with an average temperature fluctuating between 41.4°F (5.2°C) and 54.5°F (12.5°C).

Temperature

The coldest month is December, with an average high-temperature of 54.5°F (12.5°C) and an average low-temperature of 41.4°F (5.2°C).

Humidity

In Grimes, the average relative humidity in December is 69%.

Rainfall

In Grimes, in December, it is raining for 11.1 days, with typically 3.03" (77mm) of accumulated precipitation. In Grimes, during the entire year, the rain falls for 75.1 days and collects up to 17.09" (434mm) of precipitation.

Daylight

With an average of 9h and 30min of daylight, December has the shortest days of the year.
On the first day of the month, sunrise is at 7:08 am and sunset at 4:45 pm. On the last day of December, sunrise is at 7:26 am and sunset at 4:55 pm PST.

Sunshine

With an average of 5.8h of sunshine, December has the least sunshine of the year.

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 value of 3 to 5 symbolizes a medium health hazard from unprotected exposure to Sun's UV rays for ordinary individuals.
Note: The average daily UV index of 3 in December transforms into the following instructions:
Ensure safety - Recommendations to avert sunburn are presented. Around midday, solar radiation is most harmful; hence, exposure should be limited. Always opt for UVA and UVB-resistant sunglasses on radiant days.
Updated: Jun 18, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the coldest months?

In Grimes, December is the month with the lowest recorded average temperatures, measuring a high of 54.5°F (12.5°C) and a low of 41.4°F (5.2°C).

What are the temperatures in December?

Grimes in December has an average high-temperature of 54.5°F (12.5°C) and an average low-temperature of 41.4°F (5.2°C). The average heat index (a.k.a. 'feels like', 'felt air temperature'), which calculates the temperature value influenced by the moisture in the air, in June is evaluated at 91.4°F (33°C).

What is the average humidity in December?

In Grimes, the average relative humidity in December is 69%.

How much does it rain in December?

In December, the rain falls for 11.1 days. Throughout December, 3.03" (77mm) of precipitation is accumulated.

What is the month with the shortest days in Grimes?

The month with the shortest days in Grimes is December, with an average of 9h and 30min of daylight.

How many hours of daylight does Grimes have in December?

In December, the average day length is 9h and 29min.

What time are sunrise and sunset in December?

In December, on the first day of the month, sunrise is at 7:08 am and sunset at 4:45 pm. On the last day of the month, sunrise is at 7:26 am and sunset at 4:55 pm PST.

What is the month with the least sunshine?

With an average of 5.8h of sunshine, December has the least sunshine of the year in Grimes.

How many hours of sunshine does Grimes have in December?

In Grimes, the average sunshine duration in December is 5.8h.

What is the month with the lowest UV index?

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

What is the UV index intensity in December?

In Grimes, 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
Grimes, CA

Average temperature in December - Grimes, CA
  • Average high temperature in December: 54.5°F

The warmest month (with the highest average high temperature) is July (97.2°F).
The month with the lowest average high temperature is December (54.5°F).

  • Average low temperature in December: 41.4°F

The month with the highest average low temperature is July (62.1°F).
The coldest month (with the lowest average low temperature) is December (41.4°F).

Average pressure in December
Grimes, CA

Average pressure in December - Grimes, CA
  • Average pressure in December: 30.13"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).

Average wind speed in December
Grimes, CA

Average wind speed in December - Grimes, CA
  • Average wind speed in December: 5.3mph

The windiest month (with the highest average wind speed) is March (6.1mph).
The calmest month (with the lowest average wind speed) is September (4.5mph).

Average humidity in December
Grimes, CA

Average humidity in December - Grimes, CA
  • Average humidity in December: 69%

The month with the highest relative humidity is March (73%).
The months with the lowest relative humidity are July and September (38%).

Average rainfall in December
Grimes, CA

Average rainfall in December - Grimes, CA
  • Average rainfall in December: 3.03"

The wettest month (with the highest rainfall) is February (3.07").
The driest months (with the least rainfall) are July and August (0.04").

Average rainfall days in December
Grimes, CA

Average rainfall days in December - Grimes, CA
  • Average rainfall days in December: 11.1 days

The month with the highest number of rainy days is March (13.8 days).
The month with the least rainy days is July (0.9 days).

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

Average daylight in December / Average sunshine in December - Grimes, CA
  • Average daylight in December: 9h and 3min

The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).

  • Average sunshine in December: 5h and 5min

The month with the most sunshine is July (Average sunshine: 12h and 12min).
The month with the least sunshine is December (Average sunshine: 5h and 48min).

Average sunshine days in December
Grimes, CA

Average sunshine days in December - Grimes, CA
  • Average sunshine days in December: 19.3 days

The month with the most sunshine days is July (29.7 days).
The month with the least sunshine days is March (16.2 days).

Average UV index in December
Grimes, CA

Average UV index in December - Grimes, CA
  • Average UV index in December: 3

The months with the highest UV index are June and July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 3).

Average cloud cover in December
Grimes, CA

Average cloud cover in December - Grimes, CA
  • Average cloud cover in December: 35

The month with the most cloud cover is March (Cloud cover 37).
The month with the least cloud cover is July (Cloud cover 4).

Average visibility in December
Grimes, CA

Average visibility in December - Grimes, 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).

Grimes, California, USA

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