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December Weather in McAllen, United States

Last updated: June 24, 2025

In McAllen, United States, the average temperature in December is a mild 18°C (64°F). However, temperatures can fluctuate significantly, with a minimum of 1°C (34°F) and a maximum reaching 34°C (94°F). Expect about 21 mm (0.8 in) of precipitation over approximately 3 days, accompanied by a relatively high average humidity of 86%. Enjoy the variety this month has to offer!

December Temperature in McAllen

In December in McAllen, the average temperature is 18°C (64°F). The maximum can reach 34°C (94°F), while the minimum can drop to as low as 1°C (34°F). This range of temperatures makes McAllen a versatile destination for travelers, offering both warm and cool experiences to enjoy.

December Weather in McAllen: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in McAllen, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In McAllen, December typically has an average temperature of 18°C (64°F), with highs reaching up to 34°C (94°F) and lows dropping to around 1°C (34°F).
JanFebMarAprMayJunJulAugSepOctNovDec616572778285868884776964
Data source: Temperature data for McAllen generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

December Precipitation in McAllen

In McAllen in December, the precipitation amount is 21 mm (0.8 in) over a period of 3 days.

December Precipitation Trends in McAllen

The chart displays monthly precipitation patterns in McAllen, with values for each month alongside December’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how December’s conditions compare to those of other months. In McAllen, December typically receives around 21 mm (0.8 inches) of precipitation spread over approximately 3 days.
JanFebMarAprMayJunJulAugSepOctNovDec2021313187811002296513021
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in McAllen

In McAllen in December humidity is 86%. With an average temperature of 18°C (64°F), this humidity feels like a warm embrace, making travel slightly uncomfortable as the air becomes thick and sticky, often leading to clammy skin and a constant need for hydration.

December Average Humidity in McAllen

This chart illustrates the average monthly humidity levels in McAllen, with December’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In December, average humidity in McAllen is approximately 86%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec83%79%76%77%80%73%66%65%73%76%80%86%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in McAllen

In McAllen in December, the maximum UV index is 6, which corresponds to a high Exposure Category. The time to burn is approximately 25 minutes. To find the hourly UV index in McAllen, you can refer to this Hourly UV Index in McAllen.

Maximum UV Index Levels in McAllen for December

The chart shows the monthly maximum UV Index (UVI) for McAllen in December, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In December, the maximum UV index in McAllen typically reaches 6, which falls under the high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec6910111212121211976
Data source: McAllen December UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

How December Weather in McAllen Compares to Other Months

Weather in McAllen varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in McAllen, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in McAllen, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather16°C (62°F)20 mm (0.8 inches)83%high
February Weather18°C (65°F)21 mm (0.8 inches)79%very high
March Weather22°C (72°F)31 mm (1.2 inches)76%very high
April Weather25°C (78°F)31 mm (1.2 inches)77%extreme
May Weather28°C (83°F)87 mm (3.4 inches)80%extreme
June Weather30°C (86°F)81 mm (3.2 inches)73%extreme
July Weather30°C (87°F)100 mm (3.9 inches)66%extreme
August Weather31°C (88°F)22 mm (0.9 inches)65%extreme
September Weather29°C (84°F)96 mm (3.8 inches)73%extreme
October Weather25°C (77°F)51 mm (2.0 inches)76%very high
November Weather20°C (69°F)30 mm (1.2 inches)80%high
December Weather18°C (64°F)21 mm (0.8 inches)86%high

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