December is one of the cooler months of the year in Stone Mountain, with average highs near 11.8°C and lows around 1.1°C (mean 6.5°C). It is about average for rainfall, averaging 118 mm of rainfall and 82% relative humidity across the period.
December is one of the cooler months of the year in Stone Mountain. Across 45 years of records, the warmest December in Stone Mountain was 2015 — when the month averaged 12.3°C — while the coldest was 1989 at 1.1°C. Typical December days reach 11.8°C with nights near 1.1°C. The long-term trend is warming, about 0.7°C per decade.
December is about average for rainfall in Stone Mountain, averaging 118 mm of rainfall. The wettest December on record was 2015 with 293 mm, while the driest was 2010 at 35 mm.
Relative humidity in Stone Mountain during December averages 82%. The most humid December was 1992 at 89%, and the least humid was 2001 at 75%.
December receives about 2.4 kWh/m²/day of solar energy in Stone Mountain. The sunniest December was 2006 at 2.8 kWh/m²/day, and the cloudiest was 1992 at 1.9.
Average wind speed in Stone Mountain during December is 1.2 m/s. The windiest Decembers were 1983 and 2010 at 1.4 m/s, while the calmest were 1988, 2014 and 2021, among others at 1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 5.1°C | 6.4°C | 5.9°C | 7.6°C | 7.7°C | +2.6°C |
| Avg High | 10.3°C | 11.5°C | 11.4°C | 12.8°C | 13.5°C | +3.2°C |
| Avg Low | -0.1°C | 1.2°C | 0.4°C | 2.4°C | 1.9°C | +2°C |
| Avg Rain | 119 mm | 98 mm | 114 mm | 149 mm | 101 mm | -19 mm |
December temperatures in Stone Mountain have risen by about 2.6°C between 1981–1985 and 2021–2025.
December has ranged from a record low of -16.8°C (1983) to a record high of 24.9°C (2007).
Rainfall in December is about average for rainfall, averaging 118 mm, with a wettest year of 293 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 Stone Mountain
If your dates are flexible, the more temperate months of September and May tend to be the most comfortable for visiting Stone Mountain. That said, December — with days averaging 11.8°C and nights around 1.1°C (mean 6.5°C) and higher rainfall (118 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 | 13.6°C | 7.4°C | 1.2°C | 23.9°C | -7.5°C | 42 mm | 75% | 1.1 m/s | — |
| 2024 | 12.5°C | 6.8°C | 1.1°C | 21.4°C | -6.7°C | 119 mm | 79% | 1.2 m/s | 2.6 |
| 2023 | 13.9°C | 7.9°C | 1.9°C | 20.3°C | -5.8°C | 116 mm | 76% | 1.1 m/s | 2.5 |
| 2022 | 11.8°C | 6.7°C | 1.7°C | 23.3°C | -13.7°C | 118 mm | 84% | 1.1 m/s | 2.2 |
| 2021 | 17.4°C | 11.4°C | 5.5°C | 23.4°C | -2.5°C | 119 mm | 84% | 1 m/s | 2.1 |
| 2020 | 11.6°C | 5.8°C | 0.0°C | 18.3°C | -5.9°C | 88 mm | 84% | 1.1 m/s | 2.7 |
| 2019 | 13.5°C | 8.3°C | 3.1°C | 20.3°C | -4.9°C | 138 mm | 82% | 1.3 m/s | 2.3 |
| 2018 | 11.0°C | 6.8°C | 2.5°C | 20.9°C | -5.0°C | 258 mm | 89% | 1.1 m/s | 2.1 |
| 2017 | 11.7°C | 6.5°C | 1.2°C | 21.5°C | -6.4°C | 78 mm | 79% | 1.1 m/s | 2.2 |
| 2016 | 13.2°C | 7.5°C | 1.8°C | 22.3°C | -5.8°C | 81 mm | 79% | 1.2 m/s | 2.3 |
| 2015 🔥 🌧️ | 17.2°C | 12.3°C | 7.5°C | 23.6°C | -4.5°C | 293 mm | 89% | 1.1 m/s | 2.2 |
| 2014 | 13.6°C | 8.4°C | 3.1°C | 20.5°C | -3.8°C | 114 mm | 85% | 1 m/s | 2.3 |
| 2013 | 12.2°C | 7.1°C | 1.9°C | 23.6°C | -5.3°C | 219 mm | 85% | 1.2 m/s | 2.1 |
| 2012 | 14.5°C | 9.0°C | 3.4°C | 22.3°C | -4.7°C | 155 mm | 80% | 1.2 m/s | 2.2 |
| 2011 | 14.2°C | 8.5°C | 2.9°C | 21.0°C | -3.6°C | 118 mm | 83% | 1.1 m/s | 2.5 |
| 2010 | 7.0°C | 1.6°C | -3.7°C | 14.4°C | -10.3°C | 35 mm | 76% | 1.4 m/s | 2.5 |
| 2009 | 9.0°C | 4.3°C | -0.4°C | 18.8°C | -4.4°C | 213 mm | 88% | 1.3 m/s | 2 |
| 2008 | 12.6°C | 7.5°C | 2.4°C | 20.1°C | -9.1°C | 138 mm | 83% | 1.3 m/s | 2.1 |
| 2007 | 14.9°C | 9.1°C | 3.4°C | 24.9°C | -5.4°C | 113 mm | 78% | 1.1 m/s | 2.3 |
| 2006 | 14.7°C | 8.5°C | 2.3°C | 20.5°C | -7.3°C | 82 mm | 80% | 1.2 m/s | 2.8 |
| 2005 | 9.8°C | 4.3°C | -1.3°C | 18.3°C | -5.6°C | 105 mm | 81% | 1.2 m/s | 2.6 |
| 2004 | 11.2°C | 5.4°C | -0.3°C | 21.2°C | -7.7°C | 114 mm | 82% | 1.2 m/s | 2.7 |
| 2003 | 10.6°C | 4.4°C | -1.8°C | 16.4°C | -5.5°C | 77 mm | 80% | 1.3 m/s | 2.7 |
| 2002 | 9.9°C | 4.9°C | -0.1°C | 15.5°C | -5.6°C | 174 mm | 87% | 1.2 m/s | 2.3 |
| 2001 | 15.2°C | 9.1°C | 2.9°C | 23.5°C | -6.6°C | 66 mm | 75% | 1.2 m/s | 2.6 |
| 2000 | 6.4°C | 1.6°C | -3.2°C | 17.5°C | -9.3°C | 61 mm | 80% | 1.2 m/s | 2.3 |
| 1999 | 12.7°C | 6.5°C | 0.4°C | 20.5°C | -6.5°C | 60 mm | 77% | 1.1 m/s | 2.7 |
| 1998 | 14.7°C | 9.3°C | 4.0°C | 24.4°C | -3.2°C | 93 mm | 81% | 1.1 m/s | 2.1 |
| 1997 | 10.1°C | 5.4°C | 0.6°C | 16.9°C | -6.2°C | 121 mm | 87% | 1.2 m/s | 2.4 |
| 1996 | 11.7°C | 6.4°C | 1.0°C | 21.1°C | -7.6°C | 81 mm | 84% | 1.1 m/s | 2.4 |
| 1995 | 9.5°C | 4.5°C | -0.6°C | 19.1°C | -9.2°C | 83 mm | 83% | 1.2 m/s | 2.5 |
| 1994 | 12.1°C | 7.1°C | 2.1°C | 19.7°C | -4.5°C | 59 mm | 85% | 1.1 m/s | 2.2 |
| 1993 | 9.5°C | 4.7°C | -0.2°C | 18.3°C | -5.9°C | 91 mm | 84% | 1.2 m/s | 2.4 |
| 1992 | 9.3°C | 5.0°C | 0.7°C | 18.4°C | -4.6°C | 171 mm | 89% | 1.2 m/s | 1.9 |
| 1991 | 12.6°C | 7.1°C | 1.6°C | 22.9°C | -6.1°C | 110 mm | 81% | 1.2 m/s | 2.5 |
| 1990 | 13.1°C | 7.8°C | 2.6°C | 21.5°C | -7.0°C | 115 mm | 84% | 1.2 m/s | 2.1 |
| 1989 ❄️ | 6.1°C | 1.1°C | -3.8°C | 16.3°C | -15.3°C | 129 mm | 83% | 1.2 m/s | 2.4 |
| 1988 | 11.2°C | 5.2°C | -0.7°C | 19.6°C | -5.9°C | 48 mm | 81% | 1 m/s | 2.6 |
| 1987 | 12.9°C | 7.4°C | 1.9°C | 21.9°C | -5.5°C | 104 mm | 79% | 1.2 m/s | 2.3 |
| 1986 | 9.9°C | 5.2°C | 0.5°C | 17.7°C | -5.0°C | 87 mm | 87% | 1 m/s | 2 |
| 1985 | 8.7°C | 3.1°C | -2.4°C | 18.6°C | -11.9°C | 59 mm | 78% | 1.1 m/s | 2.6 |
| 1984 | 15.4°C | 9.8°C | 4.2°C | 22.0°C | -7.9°C | 80 mm | 85% | 1 m/s | 2.4 |
| 1983 | 8.3°C | 3.1°C | -2.1°C | 19.5°C | -16.8°C | 250 mm | 83% | 1.4 m/s | — |
| 1982 | 13.1°C | 8.4°C | 3.7°C | 22.6°C | -5.8°C | 158 mm | 88% | 1.2 m/s | — |
| 1981 | 7.4°C | 2.7°C | -2.1°C | 16.8°C | -11.4°C | 158 mm | 81% | 1.3 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 11.8°C with lows near 1.1°C (mean 6.5°C), based on 45 years of NASA POWER data.
December averages 118 mm of rainfall in Stone Mountain, about average for rainfall. The wettest on record was 293 mm in 2015.
The hottest December reached 24.9°C in 2007. The coldest dipped to -16.8°C in 1983.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 2.6°C. Daytime highs moved from 10.6°C to 13.8°C and overnight lows from 0.3°C to 2.3°C over the same span.
December is one of the cooler months of the year in Stone Mountain and about average for rainfall, so plan for around 11.8°C daytime highs and 1.1°C at night.
Not quite — December is the 2nd coolest month in Stone Mountain, averaging 6.5°C.
For December in Stone Mountain, pack warm layers and a jacket for chilly mornings, with typical highs of 11.8°C and lows of 1.1°C. Bring an umbrella or light rain jacket too.
Relative humidity in December averages 82% — quite humid.
Average wind speed in December is 1.2 m/s. The windiest December on record averaged 1.4 m/s (1983).
The wettest December on record was 2015 with 293 mm. On average, December sees 118 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 Stone Mountain 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.
