December is one of the cooler months of the year in Delta, with average highs near 5.6°C and lows around 2.4°C (mean 4°C). It is a relatively wet time of year, averaging 180 mm of rainfall and 88% relative humidity across the period.
December is one of the cooler months of the year in Delta. Across 45 years of records, the warmest December in Delta was 2023 — when the month averaged 6.8°C — while the coldest was 1983 at -0.2°C. Typical December days reach 5.6°C with nights near 2.4°C. The long-term trend is warming, about 0.4°C per decade.
December is a relatively wet time of year in Delta, averaging 180 mm of rainfall. The wettest December on record was 1998 with 304 mm, while the driest was 1985 at 54 mm.
Relative humidity in Delta during December averages 88%. The most humid December was 2025 at 92%, and the least humid was 2009 at 82%.
December receives about 0.7 kWh/m²/day of solar energy in Delta. The sunniest December was 2009 at 0.9 kWh/m²/day, and the cloudiest were 2006, 2012 and 2019 at 0.5.
Average wind speed in Delta during December is 2.5 m/s. The windiest December was 1996 at 3.1 m/s, while the calmest was 1989 at 1.6 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 3.3°C | 3.8°C | 4.1°C | 4.3°C | 4.6°C | +1.3°C |
| Avg High | 4.9°C | 5.5°C | 5.7°C | 5.7°C | 6.2°C | +1.3°C |
| Avg Low | 1.7°C | 2.2°C | 2.5°C | 2.8°C | 3.1°C | +1.4°C |
| Avg Rain | 152 mm | 201 mm | 165 mm | 179 mm | 219 mm | +67 mm |
December temperatures in Delta have risen by about 2.2°C between 1981–1985 and 2021–2025.
December has ranged from a record low of -12.2°C (1990) to a record high of 13.2°C (2014).
Rainfall in December is a relatively wet time of year, averaging 180 mm, with a wettest year of 304 mm.
A quieter season to visit Delta
If your dates are flexible, the more temperate months of August and July tend to be the most comfortable for visiting Delta. That said, December — with days averaging 5.6°C and nights around 2.4°C (mean 4°C) and higher rainfall (180 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 | 6.9°C | 5.5°C | 4.1°C | 12.7°C | -1.8°C | 279 mm | 92% | 2.4 m/s | — |
| 2024 | 7.2°C | 5.8°C | 4.4°C | 9.4°C | 2.2°C | 213 mm | 91% | 2.4 m/s | 0.7 |
| 2023 🔥 | 8.3°C | 6.8°C | 5.3°C | 11.7°C | 1.2°C | 212 mm | 91% | 2.1 m/s | 0.6 |
| 2022 | 4.2°C | 2.4°C | 0.6°C | 10.2°C | -9.4°C | 194 mm | 88% | 2.5 m/s | 0.8 |
| 2021 | 3.5°C | 1.8°C | 0.0°C | 11.2°C | -10.8°C | 172 mm | 88% | 2.7 m/s | 0.8 |
| 2020 | 7.2°C | 5.6°C | 4.0°C | 9.6°C | -0.5°C | 241 mm | 90% | 2.4 m/s | 0.7 |
| 2019 | 6.6°C | 5.4°C | 4.2°C | 9.6°C | 0.6°C | 171 mm | 90% | 2.1 m/s | 0.5 |
| 2018 | 7.0°C | 5.3°C | 3.6°C | 11.8°C | -1.0°C | 246 mm | 88% | 2.8 m/s | 0.7 |
| 2017 | 5.2°C | 3.6°C | 2.0°C | 8.3°C | -3.2°C | 152 mm | 85% | 2.1 m/s | 0.8 |
| 2016 | 3.5°C | 1.9°C | 0.2°C | 8.2°C | -6.6°C | 163 mm | 86% | 2.8 m/s | 0.7 |
| 2015 | 6.4°C | 5.0°C | 3.6°C | 11.5°C | -2.8°C | 275 mm | 89% | 2.7 m/s | 0.6 |
| 2014 | 7.1°C | 5.6°C | 4.1°C | 13.2°C | -3.2°C | 189 mm | 86% | 2.3 m/s | 0.8 |
| 2013 | 4.2°C | 2.9°C | 1.5°C | 9.5°C | -6.2°C | 78 mm | 84% | 2.1 m/s | 0.7 |
| 2012 | 5.6°C | 4.5°C | 3.3°C | 9.2°C | -0.1°C | 194 mm | 89% | 2.5 m/s | 0.5 |
| 2011 | 5.4°C | 4.0°C | 2.6°C | 9.3°C | -1.1°C | 102 mm | 86% | 2 m/s | 0.8 |
| 2010 | 6.1°C | 4.6°C | 3.1°C | 10.1°C | -3.7°C | 218 mm | 87% | 2.7 m/s | 0.6 |
| 2009 | 4.2°C | 2.5°C | 0.8°C | 9.3°C | -5.5°C | 79 mm | 82% | 2.4 m/s | 0.9 |
| 2008 | 3.4°C | 1.6°C | -0.1°C | 9.8°C | -9.4°C | 150 mm | 87% | 2.8 m/s | 0.7 |
| 2007 | 5.4°C | 3.9°C | 2.5°C | 11.9°C | -1.6°C | 220 mm | 89% | 2.7 m/s | 0.6 |
| 2006 | 6.3°C | 4.8°C | 3.3°C | 10.9°C | -0.9°C | 175 mm | 88% | 2.7 m/s | 0.5 |
| 2005 | 6.5°C | 5.0°C | 3.5°C | 12.6°C | -2.2°C | 157 mm | 84% | 2.1 m/s | 0.7 |
| 2004 | 6.8°C | 5.3°C | 3.9°C | 11.6°C | 1.6°C | 194 mm | 89% | 2.2 m/s | 0.7 |
| 2003 | 6.1°C | 4.6°C | 3.1°C | 10.2°C | -2.7°C | 150 mm | 89% | 2.7 m/s | 0.6 |
| 2002 | 7.4°C | 5.7°C | 4.0°C | 13.0°C | 0.4°C | 171 mm | 89% | 2.6 m/s | 0.6 |
| 2001 | 5.8°C | 4.0°C | 2.3°C | 9.2°C | -1.2°C | 220 mm | 89% | 2.8 m/s | 0.7 |
| 2000 | 5.4°C | 3.7°C | 2.0°C | 9.6°C | -3.4°C | 130 mm | 86% | 2.4 m/s | 0.7 |
| 1999 | 6.9°C | 5.4°C | 3.9°C | 10.6°C | 1.0°C | 217 mm | 88% | 2.3 m/s | 0.6 |
| 1998 🌧️ | 5.4°C | 3.9°C | 2.3°C | 11.7°C | -9.3°C | 304 mm | 89% | 2.9 m/s | 0.6 |
| 1997 | 7.0°C | 5.3°C | 3.7°C | 10.3°C | 1.5°C | 146 mm | 90% | 2.5 m/s | 0.7 |
| 1996 | 3.6°C | 1.9°C | 0.3°C | 8.9°C | -9.0°C | 248 mm | 89% | 3.1 m/s | 0.6 |
| 1995 | 6.0°C | 4.3°C | 2.5°C | 9.6°C | -5.7°C | 218 mm | 86% | 2.7 m/s | 0.7 |
| 1994 | 5.6°C | 4.0°C | 2.5°C | 10.6°C | -4.9°C | 212 mm | 88% | 2.6 m/s | 0.7 |
| 1993 | 6.4°C | 4.8°C | 3.3°C | 11.8°C | -0.6°C | 189 mm | 84% | 2.4 m/s | 0.7 |
| 1992 | 3.9°C | 2.2°C | 0.5°C | 7.9°C | -7.3°C | 124 mm | 87% | 3 m/s | 0.7 |
| 1991 | 7.2°C | 5.6°C | 4.1°C | 10.3°C | -0.2°C | 131 mm | 88% | 2.4 m/s | 0.6 |
| 1990 | 3.0°C | 0.9°C | -1.1°C | 9.5°C | -12.2°C | 223 mm | 88% | 2.8 m/s | 0.7 |
| 1989 | 6.9°C | 5.6°C | 4.2°C | 11.7°C | 0.4°C | 127 mm | 89% | 1.6 m/s | 0.6 |
| 1988 | 6.0°C | 4.6°C | 3.2°C | 10.3°C | -1.4°C | 152 mm | 86% | 2.2 m/s | 0.7 |
| 1987 | 5.1°C | 3.5°C | 1.9°C | 10.7°C | -4.2°C | 177 mm | 84% | 2.6 m/s | 0.7 |
| 1986 | 6.1°C | 4.3°C | 2.5°C | 9.0°C | -1.3°C | 151 mm | 89% | 2.5 m/s | 0.7 |
| 1985 | 4.3°C | 2.8°C | 1.4°C | 6.7°C | -8.2°C | 54 mm | 85% | 1.9 m/s | 0.7 |
| 1984 | 2.5°C | 0.7°C | -1.1°C | 6.3°C | -8.3°C | 175 mm | 86% | 2.4 m/s | 0.7 |
| 1983 ❄️ | 1.6°C | -0.2°C | -2.0°C | 6.9°C | -10.3°C | 103 mm | 85% | 2.7 m/s | — |
| 1982 | 5.6°C | 3.9°C | 2.2°C | 10.7°C | -2.6°C | 194 mm | 87% | 2.5 m/s | — |
| 1981 | 5.7°C | 4.3°C | 2.8°C | 10.8°C | -1.4°C | 233 mm | 88% | 2.7 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 5.6°C with lows near 2.4°C (mean 4°C), based on 45 years of NASA POWER data.
December averages 180 mm of rainfall in Delta, a relatively wet time of year. The wettest on record was 304 mm in 1998.
The hottest December reached 13.2°C in 2014. The coldest dipped to -12.2°C in 1990.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 2.2°C. Daytime highs moved from 3.9°C to 6°C and overnight lows from 0.7°C to 2.9°C over the same span.
December is one of the cooler months of the year in Delta and a relatively wet time of year, so plan for around 5.6°C daytime highs and 2.4°C at night.
Yes — December is the coldest month of the year in Delta, averaging 4°C.
For December in Delta, pack warm layers and a jacket for chilly mornings, with typical highs of 5.6°C and lows of 2.4°C. Bring an umbrella or light rain jacket too.
Relative humidity in December averages 88% — quite humid.
Average wind speed in December is 2.5 m/s. The windiest December on record averaged 3.1 m/s (1996).
The wettest December on record was 1998 with 304 mm. On average, December sees 180 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 Delta 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.
