December is one of the warmer months of the year in Adelaide River, with average highs near 33°C and lows around 25.2°C (mean 29.1°C). It is a relatively wet time of year, averaging 265 mm of rainfall and 78% relative humidity across the period.
December is one of the warmer months of the year in Adelaide River. Across 45 years of records, the warmest December in Adelaide River was 2019 — when the month averaged 32.5°C — while the coldest was 1988 at 26.8°C. Typical December days reach 33°C with nights near 25.2°C. The long-term trend is warming, about 0.2°C per decade.
December is a relatively wet time of year in Adelaide River, averaging 265 mm of rainfall. The wettest December on record was 2003 with 528 mm, while the driest was 1991 at 75 mm.
Relative humidity in Adelaide River during December averages 78%. The most humid December was 1988 at 90%, and the least humid was 2019 at 62%.
December receives about 6.3 kWh/m²/day of solar energy in Adelaide River. The sunniest Decembers were 1985, 1986 and 1991 at 7.3 kWh/m²/day, and the cloudiest was 2020 at 5.3.
Average wind speed in Adelaide River during December is 1.9 m/s. The windiest December was 2000 at 2.7 m/s, while the calmest was 2012 at 1.2 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 29.0°C | 28.6°C | 29.0°C | 29.7°C | 29.3°C | +0.3°C |
| Avg High | 33.1°C | 32.3°C | 32.8°C | 33.8°C | 33.0°C | -0.1°C |
| Avg Low | 24.8°C | 24.8°C | 25.2°C | 25.6°C | 25.6°C | +0.8°C |
| Avg Rain | 217 mm | 293 mm | 328 mm | 204 mm | 286 mm | +69 mm |
December temperatures in Adelaide River have risen by about 0.6°C between 1981–1985 and 2021–2025.
December has ranged from a record low of 20.2°C (2022) to a record high of 42.8°C (2006).
Rainfall in December is a relatively wet time of year, averaging 265 mm, with a wettest year of 528 mm.
A quieter season to visit Adelaide River
If your dates are flexible, the more temperate months of June and July tend to be the most comfortable for visiting Adelaide River. That said, December — with days averaging 33°C and nights around 25.2°C (mean 29.1°C) and higher rainfall (265 mm) — can still be rewarding for travellers who don't mind the warmth, and often means fewer crowds.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 31.2°C | 28.1°C | 25.0°C | 34.4°C | 22.7°C | 264 mm | 84% | 1.6 m/s | — |
| 2024 | 32.7°C | 29.2°C | 25.8°C | 35.1°C | 24.6°C | 288 mm | 83% | 1.7 m/s | 6.2 |
| 2023 | 35.1°C | 30.8°C | 26.5°C | 39.2°C | 25.6°C | 171 mm | 75% | 1.7 m/s | 6.3 |
| 2022 | 33.3°C | 29.1°C | 24.9°C | 39.0°C | 20.2°C | 356 mm | 77% | 2.1 m/s | 5.9 |
| 2021 | 34.3°C | 30.1°C | 25.9°C | 40.4°C | 23.1°C | 299 mm | 75% | 2 m/s | 6.1 |
| 2020 | 31.5°C | 28.4°C | 25.2°C | 36.2°C | 24.3°C | 340 mm | 84% | 1.8 m/s | 5.3 |
| 2019 🔥 | 38.0°C | 32.5°C | 27.0°C | 42.5°C | 25.9°C | 77 mm | 62% | 1.8 m/s | 6.9 |
| 2018 | 36.4°C | 31.5°C | 26.6°C | 40.9°C | 24.6°C | 86 mm | 69% | 2.3 m/s | 6.6 |
| 2017 | 36.5°C | 31.2°C | 26.0°C | 41.3°C | 22.1°C | 83 mm | 65% | 1.9 m/s | 6.8 |
| 2016 | 34.4°C | 30.2°C | 26.0°C | 41.8°C | 24.5°C | 160 mm | 73% | 2.1 m/s | 5.6 |
| 2015 | 33.1°C | 29.5°C | 25.9°C | 38.9°C | 24.9°C | 281 mm | 77% | 2.5 m/s | 5.4 |
| 2014 | 32.1°C | 28.9°C | 25.6°C | 35.5°C | 24.3°C | 231 mm | 82% | 1.4 m/s | 6.3 |
| 2013 | 31.3°C | 27.9°C | 24.5°C | 33.9°C | 23.3°C | 256 mm | 83% | 1.3 m/s | 6.2 |
| 2012 | 33.6°C | 29.5°C | 25.5°C | 37.6°C | 24.0°C | 186 mm | 76% | 1.2 m/s | 6.6 |
| 2011 | 31.7°C | 28.3°C | 24.8°C | 33.8°C | 22.7°C | 264 mm | 83% | 1.8 m/s | 6.1 |
| 2010 | 31.0°C | 27.8°C | 24.5°C | 35.9°C | 22.6°C | 414 mm | 85% | 1.8 m/s | 5.7 |
| 2009 | 32.3°C | 28.6°C | 25.0°C | 39.2°C | 23.7°C | 490 mm | 82% | 1.6 m/s | 6 |
| 2008 | 30.8°C | 27.7°C | 24.7°C | 35.0°C | 22.6°C | 483 mm | 86% | 1.7 m/s | 5.4 |
| 2007 | 32.4°C | 28.8°C | 25.2°C | 36.6°C | 23.4°C | 337 mm | 81% | 1.6 m/s | 6.1 |
| 2006 | 34.9°C | 30.2°C | 25.5°C | 42.8°C | 23.3°C | 288 mm | 72% | 1.7 m/s | 6.5 |
| 2005 | 32.9°C | 29.1°C | 25.4°C | 35.1°C | 24.2°C | 253 mm | 80% | 1.4 m/s | 6.2 |
| 2004 | 34.1°C | 29.8°C | 25.4°C | 38.0°C | 24.4°C | 290 mm | 75% | 2 m/s | 6.3 |
| 2003 🌧️ | 31.9°C | 28.7°C | 25.5°C | 36.5°C | 23.8°C | 528 mm | 83% | 2 m/s | 5.7 |
| 2002 | 35.3°C | 30.6°C | 25.9°C | 38.1°C | 24.8°C | 126 mm | 72% | 1.5 m/s | 7.1 |
| 2001 | 32.0°C | 28.3°C | 24.5°C | 35.8°C | 22.7°C | 205 mm | 82% | 2 m/s | 6.5 |
| 2000 | 31.5°C | 28.0°C | 24.4°C | 33.6°C | 21.3°C | 277 mm | 84% | 2.7 m/s | 5.8 |
| 1999 | 32.4°C | 28.5°C | 24.6°C | 35.3°C | 23.4°C | 280 mm | 81% | 2 m/s | 6.4 |
| 1998 | 30.4°C | 27.4°C | 24.3°C | 33.4°C | 21.0°C | 423 mm | 88% | 2.3 m/s | 5.7 |
| 1997 | 32.7°C | 29.0°C | 25.3°C | 36.4°C | 24.1°C | 352 mm | 79% | 1.6 m/s | 6 |
| 1996 | 31.5°C | 28.2°C | 24.8°C | 38.3°C | 23.4°C | 481 mm | 83% | 1.8 m/s | 5.9 |
| 1995 | 31.0°C | 27.8°C | 24.6°C | 33.9°C | 23.6°C | 285 mm | 85% | 1.9 m/s | 6.1 |
| 1994 | 32.0°C | 28.3°C | 24.6°C | 35.0°C | 23.6°C | 241 mm | 80% | 1.3 m/s | 6.7 |
| 1993 | 32.9°C | 28.9°C | 24.8°C | 38.2°C | 22.8°C | 355 mm | 79% | 2 m/s | 5.9 |
| 1992 | 33.5°C | 29.3°C | 25.2°C | 36.1°C | 24.0°C | 146 mm | 77% | 1.8 m/s | 6.9 |
| 1991 | 36.0°C | 30.4°C | 24.8°C | 39.4°C | 23.8°C | 75 mm | 70% | 2.2 m/s | 7.3 |
| 1990 | 31.0°C | 27.8°C | 24.7°C | 33.4°C | 23.5°C | 291 mm | 85% | 1.9 m/s | 6.6 |
| 1989 | 35.5°C | 30.4°C | 25.3°C | 40.3°C | 24.3°C | 164 mm | 68% | 1.8 m/s | 6.8 |
| 1988 ❄️ | 29.5°C | 26.8°C | 24.2°C | 32.0°C | 23.0°C | 404 mm | 90% | 2.2 m/s | 5.7 |
| 1987 | 31.8°C | 28.4°C | 25.0°C | 36.0°C | 23.7°C | 427 mm | 82% | 2.2 m/s | 6.2 |
| 1986 | 35.8°C | 30.6°C | 25.3°C | 39.0°C | 24.1°C | 110 mm | 68% | 2 m/s | 7.3 |
| 1985 | 34.4°C | 29.7°C | 25.0°C | 39.7°C | 24.1°C | 123 mm | 73% | 1.7 m/s | 7.3 |
| 1984 | 32.5°C | 28.7°C | 24.8°C | 38.1°C | 23.4°C | 180 mm | 79% | 2.2 m/s | 6 |
| 1983 | 33.6°C | 29.0°C | 24.5°C | 37.2°C | 23.1°C | 129 mm | 75% | 1.7 m/s | — |
| 1982 | 33.6°C | 29.2°C | 24.8°C | 38.4°C | 23.1°C | 165 mm | 73% | 1.5 m/s | — |
| 1981 | 31.6°C | 28.0°C | 24.4°C | 34.2°C | 23.3°C | 253 mm | 83% | 2 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 33°C with lows near 25.2°C (mean 29.1°C), based on 45 years of NASA POWER data.
December averages 265 mm of rainfall in Adelaide River, a relatively wet time of year. The wettest on record was 528 mm in 2003.
The hottest December reached 42.8°C in 2006. The coldest dipped to 20.2°C in 2022.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 0.6°C. Daytime highs moved from 33.1°C to 33.3°C and overnight lows from 24.7°C to 25.6°C over the same span.
December is one of the warmer months of the year in Adelaide River and a relatively wet time of year, so plan for around 33°C daytime highs and 25.2°C at night.
Not quite — December is the 9th coolest month in Adelaide River, averaging 29.1°C.
For December in Adelaide River, pack light, breathable clothing and sun protection, with typical highs of 33°C and lows of 25.2°C. Bring an umbrella or light rain jacket too.
Relative humidity in December averages 78% — quite humid.
Average wind speed in December is 1.9 m/s. The windiest December on record averaged 2.7 m/s (2000).
The wettest December on record was 2003 with 528 mm. On average, December sees 265 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 Adelaide River 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.
