December is one of the cooler months of the year in Gallatin, with average highs near 8.5°C and lows around -1°C (mean 3.8°C). It is a relatively wet time of year, averaging 124 mm of rainfall and 84% relative humidity across the period.
December is one of the cooler months of the year in Gallatin. Across 45 years of records, the warmest December in Gallatin was 2015 — when the month averaged 9.9°C — while the coldest was 1989 at -3.1°C. Typical December days reach 8.5°C with nights near -1°C. The long-term trend is warming, about 0.7°C per decade.
December is a relatively wet time of year in Gallatin, averaging 124 mm of rainfall. The wettest December on record was 1990 with 337 mm, while the driest was 1985 at 38 mm.
Relative humidity in Gallatin during December averages 84%. The most humid December was 1984 at 90%, and the least humid was 1999 at 75%.
December receives about 1.9 kWh/m²/day of solar energy in Gallatin. The sunniest December was 1988 at 2.4 kWh/m²/day, and the cloudiest was 1992 at 1.5.
Average wind speed in Gallatin during December is 2 m/s. The windiest Decembers were 1982 and 2008 at 2.5 m/s, while the calmest were 1986 and 2014 at 1.6 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 2.2°C | 4.0°C | 3.1°C | 4.6°C | 5.4°C | +3.2°C |
| Avg High | 6.9°C | 8.8°C | 7.9°C | 9.2°C | 10.7°C | +3.8°C |
| Avg Low | -2.4°C | -0.8°C | -1.8°C | 0.0°C | 0.2°C | +2.6°C |
| Avg Rain | 119 mm | 137 mm | 116 mm | 133 mm | 107 mm | -12 mm |
December temperatures in Gallatin have risen by about 3.3°C between 1981–1985 and 2021–2025.
December has ranged from a record low of -22.3°C (1989) to a record high of 23.3°C (1998).
Rainfall in December is a relatively wet time of year, averaging 124 mm, with a wettest year of 337 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.8°C per decade while lows rose 0.6°C per decade, widening the gap between day and night.
A quieter season to visit Gallatin
If your dates are flexible, the more temperate months of September and June tend to be the most comfortable for visiting Gallatin. That said, December — with days averaging 8.5°C and nights around -1°C (mean 3.8°C) and higher rainfall (124 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 | 9.1°C | 4.2°C | -0.8°C | 21.9°C | -10.5°C | 69 mm | 81% | 2 m/s | — |
| 2024 | 10.2°C | 5.4°C | 0.5°C | 16.5°C | -6.9°C | 138 mm | 80% | 2.1 m/s | 1.9 |
| 2023 | 12.1°C | 6.4°C | 0.7°C | 20.6°C | -6.4°C | 70 mm | 76% | 1.8 m/s | 2 |
| 2022 | 8.8°C | 3.8°C | -1.2°C | 19.4°C | -16.6°C | 128 mm | 84% | 2 m/s | 1.9 |
| 2021 | 15.3°C | 9.6°C | 4.0°C | 21.0°C | -4.5°C | 120 mm | 84% | 2.2 m/s | 2 |
| 2020 | 8.5°C | 3.2°C | -2.0°C | 17.4°C | -8.9°C | 115 mm | 84% | 1.9 m/s | 2.1 |
| 2019 | 11.2°C | 6.5°C | 1.9°C | 19.8°C | -5.6°C | 148 mm | 87% | 1.9 m/s | 1.8 |
| 2018 | 9.4°C | 5.0°C | 0.6°C | 19.3°C | -6.7°C | 168 mm | 88% | 1.9 m/s | 1.8 |
| 2017 | 7.6°C | 2.8°C | -2.0°C | 18.0°C | -12.0°C | 110 mm | 79% | 1.9 m/s | 2 |
| 2016 | 8.2°C | 3.3°C | -1.7°C | 21.4°C | -18.6°C | 184 mm | 81% | 2.1 m/s | 2 |
| 2015 🔥 | 14.6°C | 9.9°C | 5.1°C | 22.6°C | -3.7°C | 140 mm | 88% | 2.1 m/s | 1.8 |
| 2014 | 8.6°C | 4.6°C | 0.6°C | 17.6°C | -4.8°C | 90 mm | 87% | 1.6 m/s | 1.6 |
| 2013 | 7.5°C | 2.9°C | -1.6°C | 20.8°C | -10.6°C | 158 mm | 86% | 1.9 m/s | 1.9 |
| 2012 | 11.7°C | 6.6°C | 1.6°C | 21.9°C | -8.1°C | 156 mm | 84% | 2.2 m/s | 1.8 |
| 2011 | 10.0°C | 5.0°C | 0.0°C | 18.4°C | -5.4°C | 124 mm | 86% | 1.7 m/s | 1.9 |
| 2010 | 3.1°C | -0.9°C | -4.8°C | 16.0°C | -13.8°C | 50 mm | 83% | 2 m/s | 1.9 |
| 2009 | 6.8°C | 2.4°C | -2.1°C | 16.9°C | -6.3°C | 117 mm | 86% | 2.1 m/s | 1.9 |
| 2008 | 8.2°C | 2.9°C | -2.5°C | 20.0°C | -11.1°C | 171 mm | 81% | 2.5 m/s | 1.8 |
| 2007 | 10.8°C | 6.1°C | 1.3°C | 22.1°C | -5.3°C | 130 mm | 85% | 1.9 m/s | 1.8 |
| 2006 | 11.2°C | 5.6°C | 0.1°C | 19.1°C | -8.1°C | 81 mm | 84% | 1.8 m/s | 2.2 |
| 2005 | 6.5°C | 1.7°C | -3.2°C | 15.6°C | -7.9°C | 68 mm | 82% | 1.9 m/s | 2 |
| 2004 | 7.2°C | 2.6°C | -2.0°C | 18.4°C | -14.1°C | 144 mm | 86% | 2.1 m/s | 2.2 |
| 2003 | 7.6°C | 2.7°C | -2.3°C | 14.3°C | -6.4°C | 94 mm | 82% | 2.1 m/s | 1.9 |
| 2002 | 6.5°C | 2.4°C | -1.7°C | 15.9°C | -14.1°C | 145 mm | 90% | 2 m/s | 1.9 |
| 2001 | 10.9°C | 6.1°C | 1.2°C | 20.4°C | -9.0°C | 108 mm | 83% | 1.9 m/s | 2.2 |
| 2000 | 3.2°C | -1.7°C | -6.6°C | 16.5°C | -13.7°C | 100 mm | 82% | 2 m/s | 2 |
| 1999 | 10.4°C | 5.0°C | -0.5°C | 20.0°C | -6.5°C | 79 mm | 75% | 2 m/s | 2.1 |
| 1998 | 10.0°C | 5.2°C | 0.4°C | 23.3°C | -8.8°C | 163 mm | 83% | 1.9 m/s | 1.9 |
| 1997 | 7.2°C | 2.9°C | -1.4°C | 14.9°C | -7.5°C | 71 mm | 86% | 1.7 m/s | 1.8 |
| 1996 | 9.6°C | 4.7°C | -0.3°C | 18.9°C | -11.4°C | 122 mm | 87% | 2.2 m/s | 1.9 |
| 1995 | 6.5°C | 1.7°C | -3.0°C | 18.1°C | -13.9°C | 60 mm | 83% | 2 m/s | 1.9 |
| 1994 | 10.7°C | 5.7°C | 0.7°C | 18.3°C | -5.2°C | 76 mm | 87% | 1.7 m/s | 1.7 |
| 1993 | 7.0°C | 2.7°C | -1.5°C | 15.5°C | -12.4°C | 169 mm | 87% | 1.9 m/s | 1.8 |
| 1992 | 7.4°C | 2.8°C | -1.7°C | 15.2°C | -8.0°C | 94 mm | 87% | 2 m/s | 1.5 |
| 1991 | 9.3°C | 4.6°C | -0.1°C | 20.1°C | -7.8°C | 200 mm | 86% | 1.9 m/s | 1.9 |
| 1990 🌧️ | 9.9°C | 4.4°C | -1.0°C | 16.9°C | -12.4°C | 337 mm | 86% | 2.2 m/s | 1.8 |
| 1989 ❄️ | 1.6°C | -3.1°C | -7.7°C | 14.6°C | -22.3°C | 61 mm | 84% | 2.1 m/s | 2.2 |
| 1988 | 8.1°C | 3.0°C | -2.1°C | 17.0°C | -8.0°C | 140 mm | 82% | 2.2 m/s | 2.4 |
| 1987 | 9.8°C | 4.6°C | -0.7°C | 16.9°C | -5.9°C | 177 mm | 81% | 2.3 m/s | 1.7 |
| 1986 | 6.9°C | 2.6°C | -1.7°C | 16.7°C | -5.6°C | 111 mm | 88% | 1.6 m/s | 1.8 |
| 1985 | 4.4°C | -0.4°C | -5.2°C | 17.6°C | -14.2°C | 38 mm | 81% | 2.2 m/s | 2.2 |
| 1984 | 11.7°C | 7.3°C | 3.0°C | 20.2°C | -12.1°C | 103 mm | 90% | 2.1 m/s | 1.6 |
| 1983 | 3.0°C | -1.4°C | -5.7°C | 17.7°C | -21.3°C | 188 mm | 87% | 2.2 m/s | — |
| 1982 | 11.0°C | 6.6°C | 2.3°C | 22.0°C | -7.1°C | 166 mm | 86% | 2.5 m/s | — |
| 1981 | 5.3°C | 0.8°C | -3.8°C | 14.4°C | -12.3°C | 89 mm | 82% | 2 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 8.5°C with lows near -1°C (mean 3.8°C), based on 45 years of NASA POWER data.
December averages 124 mm of rainfall in Gallatin, a relatively wet time of year. The wettest on record was 337 mm in 1990.
The hottest December reached 23.3°C in 1998. The coldest dipped to -22.3°C in 1989.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 3.3°C. Daytime highs moved from 7.1°C to 11.1°C and overnight lows from -1.9°C to 0.6°C over the same span.
December is one of the cooler months of the year in Gallatin and a relatively wet time of year, so plan for around 8.5°C daytime highs and -1°C at night.
Not quite — December is the 2nd coolest month in Gallatin, averaging 3.8°C.
For December in Gallatin, pack warm layers and a jacket for chilly mornings, with typical highs of 8.5°C and lows of -1°C. Bring an umbrella or light rain jacket too.
Relative humidity in December averages 84% — quite humid.
Average wind speed in December is 2 m/s. The windiest December on record averaged 2.5 m/s (1982).
The wettest December on record was 1990 with 337 mm. On average, December sees 124 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 Gallatin 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.
