December is one of the cooler months of the year in Arlington, with average highs near 14.5°C and lows around 2.7°C (mean 8.6°C). It is about average for rainfall, averaging 71 mm of rainfall and 75% relative humidity across the period.
December is one of the cooler months of the year in Arlington. Across 45 years of records, the warmest December in Arlington was 2021 — when the month averaged 16.2°C — while the coldest was 1983 at 2.3°C. Typical December days reach 14.5°C with nights near 2.7°C. The long-term trend is warming, about 0.9°C per decade.
December is about average for rainfall in Arlington, averaging 71 mm of rainfall. The wettest December on record was 1991 with 234 mm, while the driest was 2025 at 3 mm.
Relative humidity in Arlington during December averages 75%. The most humid December was 1991 at 86%, and the least humid was 2005 at 57%.
December receives about 2.6 kWh/m²/day of solar energy in Arlington. The sunniest Decembers were 2003 and 2004 at 3.1 kWh/m²/day, and the cloudiest were 1992 and 2014 at 2.
Average wind speed in Arlington during December is 3 m/s. The windiest December was 2008 at 3.7 m/s, while the calmest was 1986 at 2.2 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 6.9°C | 8.5°C | 7.9°C | 9.0°C | 11.5°C | +4.6°C |
| Avg High | 12.7°C | 14.2°C | 14.1°C | 14.8°C | 17.7°C | +5°C |
| Avg Low | 1.2°C | 2.8°C | 1.9°C | 3.3°C | 5.3°C | +4.1°C |
| Avg Rain | 67 mm | 100 mm | 59 mm | 65 mm | 58 mm | -9 mm |
December temperatures in Arlington have risen by about 4.8°C between 1981–1985 and 2021–2025.
December has ranged from a record low of -17.2°C (1989) to a record high of 29.5°C (2005).
Rainfall in December is about average for rainfall, averaging 71 mm, with a wettest year of 234 mm.
A quieter season to visit Arlington
If your dates are flexible, the more temperate months of May and October tend to be the most comfortable for visiting Arlington. That said, December — with days averaging 14.5°C and nights around 2.7°C (mean 8.6°C) and moderate rainfall (71 mm) — can still be rewarding for travellers who don't mind the cooler conditions, and often means fewer crowds.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 17.5°C | 11.1°C | 4.6°C | 29.1°C | -3.5°C | 3 mm | 71% | 3 m/s | — |
| 2024 | 18.1°C | 12.1°C | 6.2°C | 25.5°C | -0.4°C | 100 mm | 75% | 2.7 m/s | 2.6 |
| 2023 | 16.9°C | 10.6°C | 4.3°C | 25.0°C | -1.5°C | 78 mm | 71% | 2.7 m/s | 3 |
| 2022 | 14.9°C | 9.6°C | 4.3°C | 25.0°C | -10.9°C | 38 mm | 75% | 2.8 m/s | 2.4 |
| 2021 🔥 | 22.4°C | 16.2°C | 10.1°C | 28.6°C | -0.6°C | 12 mm | 72% | 3.1 m/s | 2.7 |
| 2020 | 16.2°C | 9.2°C | 2.2°C | 25.1°C | -3.6°C | 114 mm | 69% | 3 m/s | 2.8 |
| 2019 | 16.3°C | 9.9°C | 3.5°C | 23.1°C | -2.8°C | 22 mm | 71% | 2.6 m/s | 2.9 |
| 2018 | 13.3°C | 8.5°C | 3.6°C | 20.4°C | -2.0°C | 101 mm | 81% | 3.1 m/s | 2.5 |
| 2017 | 14.5°C | 8.8°C | 3.2°C | 27.4°C | -5.9°C | 74 mm | 68% | 2.7 m/s | 2.3 |
| 2016 | 15.0°C | 9.4°C | 3.9°C | 25.7°C | -8.0°C | 25 mm | 70% | 3.1 m/s | 2.2 |
| 2015 | 16.5°C | 10.8°C | 5.0°C | 24.0°C | -1.9°C | 121 mm | 82% | 2.8 m/s | 3 |
| 2014 | 15.1°C | 10.4°C | 5.7°C | 25.6°C | -1.7°C | 38 mm | 78% | 2.8 m/s | 2 |
| 2013 | 11.7°C | 5.7°C | -0.3°C | 24.1°C | -9.6°C | 58 mm | 79% | 2.6 m/s | 2.6 |
| 2012 | 16.9°C | 10.3°C | 3.8°C | 28.1°C | -6.1°C | 47 mm | 64% | 3.1 m/s | 2.8 |
| 2011 | 13.4°C | 8.0°C | 2.7°C | 21.0°C | -6.2°C | 125 mm | 79% | 2.7 m/s | 2.2 |
| 2010 | 15.1°C | 8.6°C | 2.1°C | 28.0°C | -5.4°C | 37 mm | 66% | 3.3 m/s | 3 |
| 2009 | 10.5°C | 5.3°C | 0.1°C | 21.8°C | -6.1°C | 50 mm | 81% | 2.8 m/s | 2.5 |
| 2008 | 14.8°C | 8.2°C | 1.6°C | 25.3°C | -5.3°C | 21 mm | 64% | 3.7 m/s | 2.9 |
| 2007 | 15.4°C | 8.7°C | 2.1°C | 26.5°C | -5.5°C | 51 mm | 74% | 3 m/s | 2.8 |
| 2006 | 15.6°C | 9.3°C | 3.1°C | 25.2°C | -6.3°C | 78 mm | 72% | 3.1 m/s | 3 |
| 2005 | 15.1°C | 8.4°C | 1.7°C | 29.5°C | -7.0°C | 8 mm | 57% | 3 m/s | 3 |
| 2004 | 14.3°C | 8.3°C | 2.3°C | 22.5°C | -7.5°C | 23 mm | 77% | 2.9 m/s | 3.1 |
| 2003 | 16.3°C | 9.5°C | 2.8°C | 23.5°C | -3.5°C | 25 mm | 67% | 3.6 m/s | 3.1 |
| 2002 | 14.5°C | 8.7°C | 3.0°C | 22.0°C | -4.9°C | 128 mm | 79% | 3 m/s | 2.5 |
| 2001 | 15.3°C | 9.4°C | 3.4°C | 24.9°C | -4.2°C | 121 mm | 74% | 2.8 m/s | 2.7 |
| 2000 | 8.9°C | 3.6°C | -1.6°C | 20.7°C | -6.1°C | 85 mm | 81% | 3 m/s | 2.5 |
| 1999 | 16.3°C | 9.6°C | 2.9°C | 26.4°C | -3.5°C | 67 mm | 66% | 3.3 m/s | 2.9 |
| 1998 | 13.6°C | 8.3°C | 3.0°C | 25.6°C | -6.2°C | 121 mm | 82% | 2.9 m/s | 2.4 |
| 1997 | 12.9°C | 7.0°C | 1.2°C | 21.9°C | -5.1°C | 171 mm | 77% | 2.9 m/s | 2.8 |
| 1996 | 15.4°C | 8.9°C | 2.5°C | 24.5°C | -6.7°C | 35 mm | 79% | 3.3 m/s | 2.9 |
| 1995 | 15.3°C | 9.1°C | 2.8°C | 27.2°C | -6.8°C | 52 mm | 71% | 3.2 m/s | 2.7 |
| 1994 | 14.4°C | 9.3°C | 4.1°C | 23.6°C | -3.6°C | 113 mm | 85% | 2.3 m/s | 2.3 |
| 1993 | 13.7°C | 8.2°C | 2.7°C | 22.6°C | -4.8°C | 54 mm | 79% | 3.1 m/s | 2.6 |
| 1992 | 13.9°C | 8.6°C | 3.3°C | 23.7°C | -2.3°C | 112 mm | 82% | 3 m/s | 2 |
| 1991 🌧️ | 13.4°C | 9.0°C | 4.6°C | 22.6°C | -2.4°C | 234 mm | 86% | 3 m/s | 2.4 |
| 1990 | 13.0°C | 7.0°C | 0.9°C | 23.7°C | -10.0°C | 43 mm | 74% | 3.1 m/s | 2.6 |
| 1989 | 10.0°C | 3.5°C | -2.9°C | 23.6°C | -17.2°C | 12 mm | 60% | 3.2 m/s | 2.9 |
| 1988 | 15.1°C | 8.7°C | 2.3°C | 21.9°C | -4.3°C | 69 mm | 74% | 2.8 m/s | 2.6 |
| 1987 | 13.4°C | 7.7°C | 2.0°C | 23.0°C | -5.4°C | 109 mm | 79% | 3.1 m/s | 2.3 |
| 1986 | 11.7°C | 6.9°C | 2.1°C | 19.1°C | -3.8°C | 76 mm | 83% | 2.2 m/s | 2.2 |
| 1985 | 11.8°C | 5.5°C | -0.7°C | 21.7°C | -7.1°C | 57 mm | 79% | 2.9 m/s | 3 |
| 1984 | 17.0°C | 11.6°C | 6.3°C | 23.6°C | -4.6°C | 145 mm | 85% | 3.2 m/s | 2.1 |
| 1983 ❄️ | 7.7°C | 2.3°C | -3.1°C | 24.0°C | -14.1°C | 28 mm | 71% | 3.3 m/s | — |
| 1982 | 14.0°C | 8.5°C | 3.0°C | 26.2°C | -6.2°C | 100 mm | 78% | 3.2 m/s | — |
| 1981 | 13.5°C | 7.7°C | 2.0°C | 22.7°C | -6.2°C | 6 mm | 77% | 3.1 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 14.5°C with lows near 2.7°C (mean 8.6°C), based on 45 years of NASA POWER data.
December averages 71 mm of rainfall in Arlington, about average for rainfall. The wettest on record was 234 mm in 1991.
The hottest December reached 29.5°C in 2005. The coldest dipped to -17.2°C in 1989.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 4.8°C. Daytime highs moved from 12.8°C to 18°C and overnight lows from 1.5°C to 5.9°C over the same span.
December is one of the cooler months of the year in Arlington and about average for rainfall, so plan for around 14.5°C daytime highs and 2.7°C at night.
Not quite — December is the 2nd coolest month in Arlington, averaging 8.6°C.
For December in Arlington, pack warm layers and a jacket for chilly mornings, with typical highs of 14.5°C and lows of 2.7°C. Bring an umbrella or light rain jacket too.
Relative humidity in December averages 75% — moderately humid.
Average wind speed in December is 3 m/s. The windiest December on record averaged 3.7 m/s (2008).
The wettest December on record was 1991 with 234 mm. On average, December sees 71 mm.
All figures are derived from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis, covering 1981–2025.
Explore how the weather in Arlington behaves each December, based on 45 years of NASA POWER climate data from 1981 to 2025. This page breaks down average temperatures, rainfall, humidity, wind and solar radiation for December specifically, along with year-by-year records and how the month has changed over the decades.
