December is one of the cooler months of the year in Chattanooga, with average highs near 10.6°C and lows around 0.3°C (mean 5.5°C). It is a relatively wet time of year, averaging 130 mm of rainfall and 84% relative humidity across the period.
December is one of the cooler months of the year in Chattanooga. Across 45 years of records, the warmest December in Chattanooga was 2015 — when the month averaged 11.6°C — while the coldest was 1989 at -0.5°C. Typical December days reach 10.6°C with nights near 0.3°C. The long-term trend is warming, about 0.7°C per decade.
December is a relatively wet time of year in Chattanooga, averaging 130 mm of rainfall. The wettest December on record was 2015 with 296 mm, while the driest was 2010 at 44 mm.
Relative humidity in Chattanooga during December averages 84%. The most humid December was 2018 at 89%, and the least humid was 2025 at 76%.
December receives about 2 kWh/m²/day of solar energy in Chattanooga. The sunniest Decembers were 1988, 2001 and 2006 at 2.4 kWh/m²/day, and the cloudiest was 1992 at 1.5.
Average wind speed in Chattanooga during December is 0.5 m/s. The windiest December was 1990 at 0.6 m/s, while the calmest were 1986, 1992 and 2014, among others at 0.4 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 4.1°C | 5.5°C | 4.9°C | 6.5°C | 7.0°C | +2.9°C |
| Avg High | 9.1°C | 10.6°C | 10.2°C | 11.5°C | 12.5°C | +3.4°C |
| Avg Low | -1.0°C | 0.5°C | -0.4°C | 1.5°C | 1.4°C | +2.4°C |
| Avg Rain | 118 mm | 135 mm | 122 mm | 153 mm | 114 mm | -4 mm |
December temperatures in Chattanooga have risen by about 3°C between 1981–1985 and 2021–2025.
December has ranged from a record low of -17.4°C (1983) to a record high of 23.8°C (1998).
Rainfall in December is a relatively wet time of year, averaging 130 mm, with a wettest year of 296 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 Chattanooga
If your dates are flexible, the more temperate months of September and May tend to be the most comfortable for visiting Chattanooga. That said, December — with days averaging 10.6°C and nights around 0.3°C (mean 5.5°C) and higher rainfall (130 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 | 12.4°C | 6.4°C | 0.4°C | 23.0°C | -7.5°C | 47 mm | 76% | 0.5 m/s | — |
| 2024 | 11.7°C | 6.3°C | 1.0°C | 21.2°C | -6.6°C | 105 mm | 79% | 0.5 m/s | 2.1 |
| 2023 | 13.1°C | 7.3°C | 1.5°C | 18.8°C | -5.6°C | 157 mm | 78% | 0.5 m/s | 2.3 |
| 2022 | 11.0°C | 6.1°C | 1.2°C | 22.2°C | -13.3°C | 143 mm | 84% | 0.5 m/s | 2 |
| 2021 | 16.5°C | 10.7°C | 4.9°C | 22.0°C | -3.1°C | 118 mm | 85% | 0.5 m/s | 2 |
| 2020 | 10.3°C | 4.9°C | -0.4°C | 17.7°C | -6.9°C | 110 mm | 84% | 0.5 m/s | 2.2 |
| 2019 | 13.2°C | 8.0°C | 2.8°C | 21.1°C | -4.4°C | 151 mm | 85% | 0.5 m/s | 2.2 |
| 2018 | 10.1°C | 5.9°C | 1.7°C | 20.1°C | -6.0°C | 215 mm | 89% | 0.5 m/s | 1.7 |
| 2017 | 10.1°C | 5.2°C | 0.3°C | 19.3°C | -7.8°C | 89 mm | 79% | 0.5 m/s | 2.1 |
| 2016 | 11.4°C | 5.9°C | 0.3°C | 21.8°C | -5.8°C | 121 mm | 82% | 0.5 m/s | 2.1 |
| 2015 🔥 🌧️ | 16.3°C | 11.6°C | 6.9°C | 23.3°C | -4.1°C | 296 mm | 89% | 0.5 m/s | 2 |
| 2014 | 12.0°C | 7.0°C | 2.0°C | 19.5°C | -4.3°C | 116 mm | 87% | 0.4 m/s | 1.7 |
| 2013 | 11.1°C | 6.1°C | 1.2°C | 22.9°C | -5.9°C | 198 mm | 86% | 0.5 m/s | 1.9 |
| 2012 | 13.2°C | 7.9°C | 2.6°C | 21.5°C | -5.6°C | 158 mm | 83% | 0.5 m/s | 1.9 |
| 2011 | 12.6°C | 7.2°C | 1.8°C | 18.6°C | -4.8°C | 146 mm | 86% | 0.5 m/s | 2.1 |
| 2010 | 5.1°C | 0.4°C | -4.2°C | 13.1°C | -12.1°C | 44 mm | 80% | 0.5 m/s | 2 |
| 2009 | 8.2°C | 3.6°C | -1.1°C | 17.7°C | -5.5°C | 176 mm | 87% | 0.5 m/s | 1.9 |
| 2008 | 10.9°C | 5.8°C | 0.6°C | 18.6°C | -9.8°C | 208 mm | 84% | 0.5 m/s | 1.9 |
| 2007 | 13.7°C | 8.2°C | 2.7°C | 23.3°C | -5.6°C | 86 mm | 83% | 0.5 m/s | 2 |
| 2006 | 13.6°C | 7.5°C | 1.4°C | 19.8°C | -7.0°C | 71 mm | 81% | 0.5 m/s | 2.4 |
| 2005 | 8.0°C | 2.8°C | -2.4°C | 16.4°C | -6.2°C | 95 mm | 84% | 0.5 m/s | 2.1 |
| 2004 | 10.1°C | 4.8°C | -0.5°C | 21.1°C | -7.9°C | 148 mm | 83% | 0.5 m/s | 2.3 |
| 2003 | 9.4°C | 3.6°C | -2.2°C | 15.5°C | -5.7°C | 97 mm | 82% | 0.5 m/s | 2.2 |
| 2002 | 9.2°C | 4.3°C | -0.6°C | 15.5°C | -6.5°C | 161 mm | 87% | 0.5 m/s | 2 |
| 2001 | 12.8°C | 7.5°C | 2.1°C | 21.8°C | -6.2°C | 112 mm | 81% | 0.5 m/s | 2.4 |
| 2000 | 5.7°C | 0.8°C | -4.1°C | 16.8°C | -10.9°C | 63 mm | 81% | 0.5 m/s | 2 |
| 1999 | 12.2°C | 6.0°C | -0.2°C | 19.8°C | -6.8°C | 51 mm | 76% | 0.5 m/s | 2.3 |
| 1998 | 12.5°C | 7.3°C | 2.2°C | 23.8°C | -7.2°C | 156 mm | 86% | 0.5 m/s | 1.9 |
| 1997 | 9.1°C | 4.4°C | -0.2°C | 15.6°C | -6.9°C | 88 mm | 86% | 0.5 m/s | 1.9 |
| 1996 | 10.9°C | 5.8°C | 0.6°C | 20.1°C | -9.2°C | 109 mm | 85% | 0.5 m/s | 2 |
| 1995 | 7.9°C | 2.9°C | -2.0°C | 17.9°C | -10.8°C | 83 mm | 84% | 0.5 m/s | 2 |
| 1994 | 12.0°C | 6.8°C | 1.7°C | 19.6°C | -4.9°C | 85 mm | 86% | 0.5 m/s | 1.9 |
| 1993 | 8.7°C | 4.2°C | -0.4°C | 16.1°C | -6.9°C | 138 mm | 84% | 0.5 m/s | 1.9 |
| 1992 | 8.6°C | 4.3°C | 0.1°C | 16.5°C | -5.0°C | 163 mm | 89% | 0.4 m/s | 1.5 |
| 1991 | 11.7°C | 6.5°C | 1.2°C | 22.1°C | -5.5°C | 213 mm | 86% | 0.5 m/s | 2.1 |
| 1990 | 12.1°C | 6.9°C | 1.7°C | 20.9°C | -6.9°C | 263 mm | 86% | 0.6 m/s | 1.7 |
| 1989 ❄️ | 4.1°C | -0.5°C | -5.2°C | 14.6°C | -17.1°C | 107 mm | 85% | 0.5 m/s | 2.1 |
| 1988 | 9.9°C | 4.2°C | -1.5°C | 18.1°C | -5.9°C | 91 mm | 83% | 0.5 m/s | 2.4 |
| 1987 | 12.4°C | 6.6°C | 0.8°C | 20.8°C | -5.8°C | 108 mm | 80% | 0.5 m/s | 1.9 |
| 1986 | 8.8°C | 4.1°C | -0.5°C | 17.8°C | -4.8°C | 110 mm | 88% | 0.4 m/s | 1.9 |
| 1985 | 7.0°C | 1.8°C | -3.4°C | 17.6°C | -13.3°C | 62 mm | 79% | 0.5 m/s | 2.3 |
| 1984 | 14.5°C | 9.3°C | 4.1°C | 21.5°C | -8.6°C | 68 mm | 88% | 0.4 m/s | 1.9 |
| 1983 | 6.9°C | 1.9°C | -3.2°C | 19.0°C | -17.4°C | 218 mm | 85% | 0.5 m/s | — |
| 1982 | 12.0°C | 7.6°C | 3.1°C | 22.4°C | -6.6°C | 177 mm | 89% | 0.5 m/s | — |
| 1981 | 6.1°C | 1.5°C | -3.2°C | 15.7°C | -12.4°C | 119 mm | 84% | 0.5 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 10.6°C with lows near 0.3°C (mean 5.5°C), based on 45 years of NASA POWER data.
December averages 130 mm of rainfall in Chattanooga, a relatively wet time of year. The wettest on record was 296 mm in 2015.
The hottest December reached 23.8°C in 1998. The coldest dipped to -17.4°C in 1983.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 3°C. Daytime highs moved from 9.3°C to 12.9°C and overnight lows from -0.5°C to 1.8°C over the same span.
December is one of the cooler months of the year in Chattanooga and a relatively wet time of year, so plan for around 10.6°C daytime highs and 0.3°C at night.
Not quite — December is the 2nd coolest month in Chattanooga, averaging 5.5°C.
For December in Chattanooga, pack warm layers and a jacket for chilly mornings, with typical highs of 10.6°C and lows of 0.3°C. Bring an umbrella or light rain jacket too.
Relative humidity in December averages 84% — quite humid.
Average wind speed in December is 0.5 m/s. The windiest December on record averaged 0.6 m/s (1990).
The wettest December on record was 2015 with 296 mm. On average, December sees 130 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 Chattanooga 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.
