December weather forecastSan Juan, TX

December

Weather in December

The first month of the winter, December, is also an agreeable month in San Juan, Texas, with temperature in the range of an average high of 71.4°F (21.9°C) and an average low of 56.1°F (13.4°C).

Temperature

December's onset corresponds with a subtle shift in the average high-temperature, slightly moving from a moderately hot 77.7°F (25.4°C) in November to an agreeable 71.4°F (21.9°C). The month of December records an average low-temperature of 56.1°F (13.4°C).

Humidity

In San Juan, the average relative humidity in December is 68%.

Rainfall

In San Juan, in December, it is raining for 6.3 days, with typically 0.47" (12mm) of accumulated precipitation. Throughout the year, there are 94.1 rainfall days, and 9.06" (230mm) of precipitation is accumulated.

Snowfall

February through December are months without snowfall.

Daylight

With an average of 10h and 30min of daylight, December has the shortest days of the year.
On the first day of December, sunrise is at 7:03 am and sunset at 5:40 pm. On the last day of the month, sunrise is at 7:19 am and sunset at 5:51 pm CST.

Sunshine

The month with the least sunshine in San Juan is December, with an average of 5.5h of sunshine.

UV index

With an average maximum UV index of 4, December is the month with the lowest UV index in San Juan. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV radiation for the ordinary person.
Note: The maximum daily UV index of 4 during December translates into the following directions:
Heed the precautions - Suggestions to avoid sunburn are made. To protect against the Sun's most potent rays, avoid direct exposure around midday. Limit sun-induced ocular harm with sunglasses that feature UVA and UVB filtration.
Updated: Jul 23, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

The average high-temperature and low-temperature during December are 71.4°F (21.9°C) and 56.1°F (13.4°C) respectively. In October, the average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which calculates the temperature value influenced by the moisture in the air, is appraised at 95°F (35°C).

In San Juan, the average relative humidity in December is 68%.

In San Juan, during December, the rain falls for 6.3 days and regularly aggregates up to 0.47" (12mm) of precipitation.

February through December are months without snowfall in San Juan.

In San Juan, in December, it doesn't snow. In January, it regularly snows.

With an average of 10h and 30min of daylight, December has the shortest days of the year.

In San Juan, the average day length in December is 10h and 32min.

In December, on the first day of the month, sunrise is at 7:03 am and sunset at 5:40 pm. On the last day of the month, sunrise is at 7:19 am and sunset at 5:51 pm CST.

With an average of 5.5h of sunshine, December has the least sunshine of the year.

In December, the average sunshine duration in San Juan is 5.5h.

With an average maximum UV index of 4, December is the month with the lowest UV index.

In December, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a medium hazard to health from unprotected exposure to UV radiation.
Average high temperature
Average low temperature
Average pressure
Average wind speed
Average max. wind speed
Average wind speed gusts
Average humidity
Average rainfall
Average rainfall days
Average snowfall
Average snowfall days
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
San Juan, TX

  • Average high temperature in December: 71.4°F

The warmest month (with the highest average high temperature) is August (98.2°F).
The month with the lowest average high temperature is January (69.6°F).

  • Average low temperature in December: 56.1°F

The month with the highest average low temperature is August (79.7°F).
The coldest month (with the lowest average low temperature) is January (53.4°F).

Average pressure in December
San Juan, TX

  • Average pressure in December: 30.07"Hg

The month with the highest atmospheric pressure is January (30.12"Hg).
The months with the lowest atmospheric pressure are May and June (29.87"Hg).

Average wind speed in December
San Juan, TX

  • Average wind speed in December: 9.5mph

The windiest month (with the highest average wind speed) is May (12.4mph).
The calmest month (with the lowest average wind speed) is September (8.9mph).

Average humidity in December
San Juan, TX

  • Average humidity in December: 68%

The month with the highest relative humidity is May (69%).
The month with the lowest relative humidity is August (59%).

Average rainfall in December
San Juan, TX

  • Average rainfall in December: 0.47"

The wettest month (with the highest rainfall) is September (1.46").
The driest months (with the least rainfall) are January and February (0.31").

Average rainfall days in December
San Juan, TX

  • Average rainfall days in December: 6.3 days

The month with the highest number of rainy days is September (15.1 days).
The month with the least rainy days is February (5.4 days).

Average snowfall in December
San Juan, TX

  • Average snowfall in December: 0"

The month with the highest snowfall is January (0.12").
The months with the least snowfall are February, March, April, May, June, July, August, September, October, November and December (0").

Average snowfall days in December
San Juan, TX

  • Average snowfall days in December: 0 days

The month with the highest number of snowfall days is January (0.1 days).
The months with the least snowfall days are February, March, April, May, June, July, August, September, October, November and December (0 days).

Average daylight in December /
Average sunshine in December
San Juan, TX

  • Average daylight in December: 10h and 30min

The month with the longest days is June (Average daylight: 13h and 48min).
The month with the shortest days is December (Average daylight: 10h and 30min).

  • Average sunshine in December: 5h and 30min

The month with the most sunshine is July (Average sunshine: 11h and 24min).
The month with the least sunshine is December (Average sunshine: 5h and 30min).

Average sunshine days in December
San Juan, TX

  • Average sunshine days in December: 22.5 days

The month with the most sunshine days is July (23 days).
The month with the least sunshine days is September (12.5 days).

Average UV index in December
San Juan, TX

  • Average UV index in December: 4

The months with the highest UV index are July and August (UV index 8).
The month with the lowest UV index is December (UV index 4).

Average cloud cover in December
San Juan, TX

  • Average cloud cover in December: 39

The month with the most cloud cover is December (Cloud cover 39).
The month with the least cloud cover is August (Cloud cover 18).

Average visibility in December
San Juan, TX

  • 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).