December is one of the cooler months of the year in Danbury, with average highs near 3.3°C and lows around -4.5°C (mean -0.6°C). It is about average for rainfall, averaging 101 mm of rainfall and 87% relative humidity across the period.
December is one of the cooler months of the year in Danbury. Across 45 years of records, the warmest December in Danbury was 2015 — when the month averaged 6°C — while the coldest was 1989 at -7.6°C. Typical December days reach 3.3°C with nights near -4.5°C. The long-term trend is warming, about 0.4°C per decade.
December is about average for rainfall in Danbury, averaging 101 mm of rainfall. The wettest December on record was 2023 with 218 mm, while the driest was 1989 at 31 mm.
Relative humidity in Danbury during December averages 87%. The most humid December was 1996 at 93%, and the least humid was 2000 at 80%.
December receives about 1.5 kWh/m²/day of solar energy in Danbury. The sunniest Decembers were 1989 and 2001 at 1.8 kWh/m²/day, and the cloudiest were 2013, 2014 and 2019, among others at 1.3.
Average wind speed in Danbury during December is 0.4 m/s. The windiest Decembers were 2020, 2022 and 2025, among others at 0.4 m/s, while the calmest were 2021, 2023 and 2024, among others at 0.3 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | -2.0°C | -0.2°C | -0.9°C | 0.0°C | 0.3°C | +2.3°C |
| Avg High | 2.0°C | 3.8°C | 3.1°C | 3.8°C | 4.3°C | +2.3°C |
| Avg Low | -6.0°C | -4.2°C | -4.9°C | -3.7°C | -3.7°C | +2.3°C |
| Avg Rain | 76 mm | 98 mm | 111 mm | 110 mm | 114 mm | +38 mm |
December temperatures in Danbury have risen by about 1.9°C between 1981–1985 and 2021–2025.
December has ranged from a record low of -19.1°C (1989) to a record high of 20.5°C (2015).
Rainfall in December is about average for rainfall, averaging 101 mm, with a wettest year of 218 mm.
A quieter season to visit Danbury
If your dates are flexible, the more temperate months of August and July tend to be the most comfortable for visiting Danbury. That said, December — with days averaging 3.3°C and nights around -4.5°C (mean -0.6°C) and higher rainfall (101 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 | 1.1°C | -3.0°C | -7.0°C | 12.5°C | -12.7°C | 86 mm | 83% | 0.4 m/s | — |
| 2024 | 3.6°C | -0.4°C | -4.4°C | 14.8°C | -14.6°C | 118 mm | 85% | 0.3 m/s | 1.7 |
| 2023 🌧️ | 6.7°C | 2.8°C | -1.0°C | 16.3°C | -5.9°C | 218 mm | 91% | 0.3 m/s | 1.4 |
| 2022 | 4.2°C | -0.2°C | -4.6°C | 13.6°C | -15.0°C | 111 mm | 86% | 0.4 m/s | 1.6 |
| 2021 | 6.3°C | 2.5°C | -1.4°C | 15.0°C | -6.5°C | 46 mm | 86% | 0.3 m/s | 1.5 |
| 2020 | 3.9°C | -0.1°C | -4.1°C | 15.5°C | -17.1°C | 107 mm | 88% | 0.4 m/s | 1.5 |
| 2019 | 2.5°C | -1.1°C | -4.7°C | 11.9°C | -13.0°C | 154 mm | 92% | 0.3 m/s | 1.3 |
| 2018 | 3.9°C | 0.2°C | -3.5°C | 13.6°C | -8.5°C | 145 mm | 90% | 0.3 m/s | 1.6 |
| 2017 | 1.4°C | -2.2°C | -5.8°C | 12.5°C | -16.0°C | 47 mm | 81% | 0.4 m/s | 1.4 |
| 2016 | 2.9°C | -0.9°C | -4.8°C | 13.5°C | -12.9°C | 80 mm | 86% | 0.3 m/s | 1.6 |
| 2015 🔥 | 10.0°C | 6.0°C | 2.0°C | 20.5°C | -3.7°C | 109 mm | 88% | 0.3 m/s | 1.4 |
| 2014 | 3.9°C | 0.4°C | -3.1°C | 12.8°C | -8.9°C | 109 mm | 88% | 0.3 m/s | 1.3 |
| 2013 | 2.1°C | -1.9°C | -5.8°C | 14.7°C | -18.7°C | 97 mm | 90% | 0.4 m/s | 1.3 |
| 2012 | 5.0°C | 1.3°C | -2.4°C | 14.4°C | -10.2°C | 137 mm | 89% | 0.4 m/s | 1.3 |
| 2011 | 6.0°C | 1.8°C | -2.4°C | 14.0°C | -7.3°C | 115 mm | 90% | 0.4 m/s | 1.7 |
| 2010 | 0.5°C | -3.1°C | -6.7°C | 15.0°C | -11.3°C | 103 mm | 85% | 0.4 m/s | 1.6 |
| 2009 | 2.2°C | -1.7°C | -5.5°C | 16.7°C | -13.1°C | 138 mm | 85% | 0.4 m/s | 1.6 |
| 2008 | 2.9°C | -1.2°C | -5.3°C | 14.6°C | -15.3°C | 164 mm | 90% | 0.4 m/s | 1.4 |
| 2007 | 1.7°C | -1.7°C | -5.1°C | 11.7°C | -10.9°C | 134 mm | 90% | 0.4 m/s | 1.4 |
| 2006 | 6.9°C | 2.6°C | -1.8°C | 18.1°C | -9.1°C | 53 mm | 87% | 0.3 m/s | 1.6 |
| 2005 | 1.6°C | -2.3°C | -6.2°C | 9.3°C | -17.9°C | 97 mm | 90% | 0.4 m/s | 1.6 |
| 2004 | 3.3°C | -0.9°C | -5.1°C | 12.7°C | -15.5°C | 97 mm | 88% | 0.3 m/s | 1.5 |
| 2003 | 3.1°C | -0.8°C | -4.6°C | 11.9°C | -9.4°C | 145 mm | 89% | 0.4 m/s | 1.6 |
| 2002 | 1.3°C | -2.5°C | -6.2°C | 11.6°C | -12.6°C | 115 mm | 90% | 0.4 m/s | 1.5 |
| 2001 | 7.4°C | 2.9°C | -1.6°C | 19.8°C | -8.4°C | 55 mm | 81% | 0.3 m/s | 1.8 |
| 2000 | 0.6°C | -3.5°C | -7.6°C | 15.5°C | -12.5°C | 110 mm | 80% | 0.4 m/s | 1.7 |
| 1999 | 4.7°C | 0.6°C | -3.5°C | 14.1°C | -11.4°C | 59 mm | 83% | 0.4 m/s | 1.6 |
| 1998 | 6.7°C | 2.0°C | -2.7°C | 20.3°C | -12.2°C | 34 mm | 81% | 0.3 m/s | 1.5 |
| 1997 | 3.1°C | -0.9°C | -4.9°C | 9.6°C | -13.7°C | 82 mm | 89% | 0.4 m/s | 1.7 |
| 1996 | 3.7°C | 0.6°C | -2.5°C | 12.6°C | -12.9°C | 188 mm | 93% | 0.3 m/s | 1.4 |
| 1995 | -0.8°C | -4.5°C | -8.2°C | 6.8°C | -13.8°C | 55 mm | 91% | 0.4 m/s | 1.7 |
| 1994 | 5.2°C | 0.8°C | -3.7°C | 14.2°C | -11.1°C | 90 mm | 85% | 0.4 m/s | 1.5 |
| 1993 | 2.7°C | -1.3°C | -5.3°C | 9.9°C | -15.9°C | 110 mm | 85% | 0.4 m/s | 1.4 |
| 1992 | 2.7°C | -0.9°C | -4.5°C | 9.4°C | -11.6°C | 119 mm | 87% | 0.4 m/s | 1.3 |
| 1991 | 4.2°C | 0.0°C | -4.2°C | 12.8°C | -12.7°C | 87 mm | 85% | 0.3 m/s | 1.6 |
| 1990 | 5.4°C | 1.3°C | -2.9°C | 16.3°C | -10.8°C | 152 mm | 87% | 0.3 m/s | 1.4 |
| 1989 ❄️ | -3.4°C | -7.6°C | -11.9°C | 3.3°C | -19.1°C | 31 mm | 83% | 0.4 m/s | 1.8 |
| 1988 | 2.3°C | -1.7°C | -5.7°C | 10.9°C | -16.6°C | 34 mm | 82% | 0.3 m/s | 1.5 |
| 1987 | 3.5°C | -0.1°C | -3.8°C | 10.5°C | -15.6°C | 49 mm | 87% | 0.4 m/s | 1.4 |
| 1986 | 3.3°C | -0.5°C | -4.4°C | 10.4°C | -11.7°C | 113 mm | 88% | 0.3 m/s | 1.5 |
| 1985 | 0.5°C | -3.6°C | -7.7°C | 7.0°C | -13.6°C | 48 mm | 87% | 0.4 m/s | 1.5 |
| 1984 | 5.4°C | 1.3°C | -2.8°C | 13.9°C | -9.6°C | 76 mm | 87% | 0.3 m/s | 1.3 |
| 1983 | 0.6°C | -3.2°C | -7.0°C | 11.4°C | -17.5°C | 187 mm | 88% | 0.4 m/s | — |
| 1982 | 5.5°C | 1.4°C | -2.8°C | 19.6°C | -12.6°C | 46 mm | 85% | 0.3 m/s | — |
| 1981 | 0.1°C | -3.7°C | -7.5°C | 8.5°C | -18.8°C | 103 mm | 92% | 0.4 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 3.3°C with lows near -4.5°C (mean -0.6°C), based on 45 years of NASA POWER data.
December averages 101 mm of rainfall in Danbury, about average for rainfall. The wettest on record was 218 mm in 2023.
The hottest December reached 20.5°C in 2015. The coldest dipped to -19.1°C in 1989.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 1.9°C. Daytime highs moved from 2.4°C to 4.4°C and overnight lows from -5.6°C to -3.7°C over the same span.
December is one of the cooler months of the year in Danbury and about average for rainfall, so plan for around 3.3°C daytime highs and -4.5°C at night.
Not quite — December is the 3rd coolest month in Danbury, averaging -0.6°C.
For December in Danbury, pack warm layers and a jacket for chilly mornings, with typical highs of 3.3°C and lows of -4.5°C. Bring an umbrella or light rain jacket too.
Relative humidity in December averages 87% — quite humid.
Average wind speed in December is 0.4 m/s. The windiest December on record averaged 0.4 m/s (1981).
The wettest December on record was 2023 with 218 mm. On average, December sees 101 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 Danbury 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.
