December is one of the cooler months of the year in Fort Smith, with average highs near 9.8°C and lows around -0.7°C (mean 4.6°C). It is one of the drier months, averaging 85 mm of rainfall and 83% relative humidity across the period.
December is one of the cooler months of the year in Fort Smith. Across 45 years of records, the warmest December in Fort Smith was 2021 — when the month averaged 11.3°C — while the coldest was 1983 at -2.5°C. Typical December days reach 9.8°C with nights near -0.7°C. The long-term trend is warming, about 0.8°C per decade.
December is one of the drier months in Fort Smith, averaging 85 mm of rainfall. The wettest December on record was 2015 with 276 mm, while the driest was 2025 at 5 mm.
Relative humidity in Fort Smith during December averages 83%. The most humid December was 1984 at 91%, and the least humid was 1989 at 66%.
December receives about 2.2 kWh/m²/day of solar energy in Fort Smith. The sunniest December was 2004 at 2.7 kWh/m²/day, and the cloudiest were 1992 and 2014 at 1.5.
Average wind speed in Fort Smith during December is 1.8 m/s. The windiest December was 2008 at 2.3 m/s, while the calmest was 1986 at 1.3 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 3.1°C | 4.6°C | 3.7°C | 5.3°C | 6.9°C | +3.8°C |
| Avg High | 8.1°C | 9.6°C | 9.2°C | 10.5°C | 12.4°C | +4.3°C |
| Avg Low | -2.0°C | -0.4°C | -1.6°C | 0.0°C | 1.3°C | +3.3°C |
| Avg Rain | 87 mm | 98 mm | 71 mm | 90 mm | 78 mm | -9 mm |
December temperatures in Fort Smith have risen by about 4.5°C between 1981–1985 and 2021–2025.
December has ranged from a record low of -19.7°C (1989) to a record high of 25.5°C (2012).
Rainfall in December is one of the drier months, averaging 85 mm, with a wettest year of 276 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.9°C per decade while lows rose 0.7°C per decade, widening the gap between day and night.
A quieter season to visit Fort Smith
If your dates are flexible, the more temperate months of September and June tend to be the most comfortable for visiting Fort Smith. That said, December — with days averaging 9.8°C and nights around -0.7°C (mean 4.6°C) and higher rainfall (85 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 | 12.9°C | 6.8°C | 0.7°C | 24.8°C | -6.8°C | 5 mm | 79% | 1.7 m/s | — |
| 2024 | 12.3°C | 7.1°C | 1.9°C | 19.7°C | -4.8°C | 112 mm | 86% | 1.7 m/s | 2.2 |
| 2023 | 12.2°C | 6.7°C | 1.2°C | 19.2°C | -3.7°C | 55 mm | 82% | 1.7 m/s | 2.2 |
| 2022 | 9.8°C | 4.9°C | 0.0°C | 18.3°C | -17.0°C | 90 mm | 83% | 1.9 m/s | 2.1 |
| 2021 🔥 | 17.4°C | 11.3°C | 5.2°C | 24.1°C | -4.6°C | 101 mm | 80% | 1.9 m/s | 2.3 |
| 2020 | 9.9°C | 4.4°C | -1.1°C | 19.5°C | -8.4°C | 104 mm | 85% | 1.8 m/s | 2.3 |
| 2019 | 11.6°C | 6.4°C | 1.1°C | 19.1°C | -4.4°C | 35 mm | 84% | 1.6 m/s | 2.4 |
| 2018 | 10.3°C | 5.6°C | 0.9°C | 18.1°C | -5.0°C | 136 mm | 84% | 1.8 m/s | 2.2 |
| 2017 | 10.6°C | 5.1°C | -0.4°C | 23.1°C | -9.5°C | 71 mm | 72% | 1.7 m/s | 2.2 |
| 2016 | 11.0°C | 5.0°C | -0.9°C | 22.0°C | -9.8°C | 28 mm | 71% | 1.8 m/s | 2 |
| 2015 🌧️ | 13.5°C | 7.8°C | 2.0°C | 20.8°C | -4.5°C | 276 mm | 88% | 2 m/s | 2.5 |
| 2014 | 9.5°C | 5.4°C | 1.3°C | 17.6°C | -4.4°C | 69 mm | 87% | 1.6 m/s | 1.5 |
| 2013 | 6.3°C | 1.2°C | -3.9°C | 18.0°C | -17.2°C | 109 mm | 89% | 1.5 m/s | 2 |
| 2012 | 13.2°C | 7.2°C | 1.3°C | 25.5°C | -6.8°C | 50 mm | 73% | 2 m/s | 2.3 |
| 2011 | 10.5°C | 5.3°C | 0.2°C | 16.5°C | -6.1°C | 84 mm | 84% | 1.6 m/s | 2.2 |
| 2010 | 9.0°C | 3.5°C | -2.0°C | 18.3°C | -6.5°C | 46 mm | 75% | 1.9 m/s | 2.3 |
| 2009 | 6.0°C | 1.6°C | -2.7°C | 17.0°C | -6.9°C | 60 mm | 86% | 1.9 m/s | 2.2 |
| 2008 | 10.2°C | 3.8°C | -2.5°C | 21.4°C | -9.8°C | 54 mm | 75% | 2.3 m/s | 2.1 |
| 2007 | 11.1°C | 5.2°C | -0.7°C | 21.7°C | -6.4°C | 85 mm | 82% | 1.9 m/s | 2.1 |
| 2006 | 10.4°C | 5.3°C | 0.2°C | 20.5°C | -11.6°C | 99 mm | 87% | 1.8 m/s | 2.4 |
| 2005 | 10.5°C | 4.3°C | -1.9°C | 20.7°C | -7.3°C | 10 mm | 71% | 1.8 m/s | 2.6 |
| 2004 | 9.7°C | 4.4°C | -0.9°C | 20.2°C | -10.4°C | 33 mm | 85% | 1.7 m/s | 2.7 |
| 2003 | 10.7°C | 4.8°C | -1.1°C | 17.2°C | -5.5°C | 49 mm | 81% | 2 m/s | 2.4 |
| 2002 | 9.3°C | 4.0°C | -1.2°C | 19.6°C | -12.3°C | 130 mm | 87% | 1.8 m/s | 2.1 |
| 2001 | 10.7°C | 5.7°C | 0.8°C | 22.5°C | -7.0°C | 135 mm | 83% | 1.7 m/s | 2.4 |
| 2000 | 3.1°C | -1.7°C | -6.4°C | 12.0°C | -14.5°C | 57 mm | 85% | 1.9 m/s | 2.3 |
| 1999 | 11.9°C | 5.9°C | -0.1°C | 22.5°C | -4.9°C | 115 mm | 79% | 1.9 m/s | 2.5 |
| 1998 | 10.4°C | 5.3°C | 0.1°C | 23.8°C | -8.2°C | 75 mm | 83% | 1.6 m/s | 2.3 |
| 1997 | 6.9°C | 2.6°C | -1.6°C | 17.1°C | -5.6°C | 127 mm | 89% | 1.8 m/s | 2 |
| 1996 | 10.1°C | 5.0°C | -0.1°C | 19.2°C | -12.4°C | 30 mm | 88% | 1.9 m/s | 2.5 |
| 1995 | 9.2°C | 4.1°C | -1.1°C | 22.5°C | -10.9°C | 84 mm | 78% | 1.7 m/s | 2.1 |
| 1994 | 10.9°C | 5.9°C | 1.0°C | 19.5°C | -6.8°C | 80 mm | 88% | 1.4 m/s | 1.8 |
| 1993 | 9.5°C | 4.5°C | -0.6°C | 19.9°C | -5.8°C | 72 mm | 86% | 1.7 m/s | 2.2 |
| 1992 | 8.7°C | 3.9°C | -0.9°C | 20.3°C | -5.8°C | 147 mm | 89% | 1.7 m/s | 1.5 |
| 1991 | 10.0°C | 5.6°C | 1.1°C | 21.2°C | -5.8°C | 129 mm | 89% | 1.7 m/s | 2.1 |
| 1990 | 8.2°C | 3.0°C | -2.3°C | 19.7°C | -14.0°C | 120 mm | 84% | 1.9 m/s | 2.1 |
| 1989 | 6.1°C | 0.0°C | -6.1°C | 18.9°C | -19.7°C | 20 mm | 66% | 1.9 m/s | 2.6 |
| 1988 | 10.2°C | 4.4°C | -1.3°C | 16.1°C | -7.9°C | 65 mm | 83% | 1.7 m/s | 2.3 |
| 1987 | 9.2°C | 4.4°C | -0.4°C | 17.9°C | -7.0°C | 220 mm | 87% | 1.8 m/s | 1.9 |
| 1986 | 8.7°C | 4.2°C | -0.3°C | 12.6°C | -4.3°C | 35 mm | 84% | 1.3 m/s | 2.1 |
| 1985 | 5.4°C | 0.6°C | -4.2°C | 15.3°C | -12.8°C | 43 mm | 86% | 1.9 m/s | 2.5 |
| 1984 | 12.5°C | 7.5°C | 2.6°C | 20.4°C | -10.0°C | 174 mm | 91% | 1.8 m/s | 1.8 |
| 1983 ❄️ | 2.1°C | -2.5°C | -7.1°C | 13.9°C | -19.2°C | 46 mm | 82% | 2.1 m/s | — |
| 1982 | 10.6°C | 5.9°C | 1.3°C | 22.3°C | -6.7°C | 171 mm | 87% | 1.9 m/s | — |
| 1981 | 8.5°C | 3.2°C | -2.1°C | 18.8°C | -8.9°C | 9 mm | 81% | 1.9 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 9.8°C with lows near -0.7°C (mean 4.6°C), based on 45 years of NASA POWER data.
December averages 85 mm of rainfall in Fort Smith, one of the drier months. The wettest on record was 276 mm in 2015.
The hottest December reached 25.5°C in 2012. The coldest dipped to -19.7°C in 1989.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 4.5°C. Daytime highs moved from 7.8°C to 12.9°C and overnight lows from -1.9°C to 1.8°C over the same span.
December is one of the cooler months of the year in Fort Smith and one of the drier months, so plan for around 9.8°C daytime highs and -0.7°C at night.
Not quite — December is the 2nd coolest month in Fort Smith, averaging 4.6°C.
For December in Fort Smith, pack warm layers and a jacket for chilly mornings, with typical highs of 9.8°C and lows of -0.7°C. Bring an umbrella or light rain jacket too.
Relative humidity in December averages 83% — quite humid.
Average wind speed in December is 1.8 m/s. The windiest December on record averaged 2.3 m/s (2008).
The wettest December on record was 2015 with 276 mm. On average, December sees 85 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 Fort Smith 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.
