December is one of the warmer months of the year in Perth, with average highs near 24.7°C and lows around 18°C (mean 21.4°C). It is one of the drier months, averaging 10 mm of rainfall and 65% relative humidity across the period.
December is one of the warmer months of the year in Perth. Across 45 years of records, the warmest December in Perth was 2019 — when the month averaged 23.9°C — while the coldest was 2005 at 18.1°C. Typical December days reach 24.7°C with nights near 18°C. The long-term trend is warming, about 0.4°C per decade.
December is one of the drier months in Perth, averaging 10 mm of rainfall. The wettest December on record was 2011 with 39 mm, while the driest was 1994 at 0 mm.
Relative humidity in Perth during December averages 65%. The most humid December was 2005 at 73%, and the least humid was 2020 at 60%.
December receives about 8.4 kWh/m²/day of solar energy in Perth. The sunniest December was 2020 at 9 kWh/m²/day, and the cloudiest was 2011 at 7.7.
Average wind speed in Perth during December is 5.6 m/s. The windiest December was 1996 at 6.3 m/s, while the calmest was 2012 at 5 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 20.5°C | 21.4°C | 20.9°C | 21.8°C | 22.5°C | +2°C |
| Avg High | 23.6°C | 24.9°C | 24.3°C | 25.1°C | 26.2°C | +2.6°C |
| Avg Low | 17.4°C | 18.0°C | 17.6°C | 18.4°C | 18.9°C | +1.5°C |
| Avg Rain | 10 mm | 8 mm | 9 mm | 16 mm | 8 mm | -2 mm |
December temperatures in Perth have risen by about 2.4°C between 1981–1985 and 2021–2025.
December has ranged from a record low of 13°C (1986) to a record high of 38.3°C (2021).
Rainfall in December is one of the drier months, averaging 10 mm, with a wettest year of 39 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.5°C per decade while lows rose 0.3°C per decade, widening the gap between day and night.
One of the best times to visit Perth
December is one of the best times to visit Perth. Expect days averaging 24.7°C and nights around 18°C (mean 21.4°C) — warmer than Perth's yearly average — with low rainfall (10 mm), so conditions are generally comfortable for sightseeing and outdoor plans.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 26.2°C | 22.5°C | 18.8°C | 35.6°C | 15.8°C | 16 mm | 63% | 5.8 m/s | — |
| 2024 | 26.1°C | 22.6°C | 19.2°C | 37.7°C | 16.3°C | 13 mm | 64% | 5.7 m/s | 8.6 |
| 2023 | 26.7°C | 23.1°C | 19.6°C | 31.7°C | 15.7°C | 2 mm | 61% | 5.6 m/s | 8.7 |
| 2022 | 25.2°C | 21.7°C | 18.3°C | 31.9°C | 15.4°C | 7 mm | 63% | 5.5 m/s | 8.7 |
| 2021 | 26.6°C | 22.9°C | 19.1°C | 38.3°C | 15.5°C | 4 mm | 62% | 5.6 m/s | 8.7 |
| 2020 | 26.2°C | 22.3°C | 18.4°C | 35.1°C | 13.4°C | 3 mm | 60% | 5.4 m/s | 9 |
| 2019 🔥 | 27.4°C | 23.9°C | 20.3°C | 35.4°C | 15.6°C | 6 mm | 62% | 5.1 m/s | 8.7 |
| 2018 | 23.9°C | 20.9°C | 17.9°C | 31.8°C | 15.1°C | 10 mm | 68% | 5.3 m/s | 8.5 |
| 2017 | 25.3°C | 21.9°C | 18.5°C | 32.4°C | 15.3°C | 23 mm | 64% | 5.9 m/s | 8.4 |
| 2016 | 23.7°C | 20.5°C | 17.3°C | 34.9°C | 14.8°C | 15 mm | 66% | 6 m/s | 8.9 |
| 2015 | 24.7°C | 21.3°C | 17.9°C | 33.7°C | 15.1°C | 10 mm | 65% | 5.6 m/s | 8.4 |
| 2014 | 23.9°C | 20.6°C | 17.3°C | 34.0°C | 14.4°C | 1 mm | 65% | 5.8 m/s | 8.6 |
| 2013 | 25.5°C | 22.1°C | 18.6°C | 34.0°C | 14.6°C | 2 mm | 63% | 5.3 m/s | 8.5 |
| 2012 | 25.9°C | 22.5°C | 19.1°C | 35.8°C | 14.7°C | 28 mm | 66% | 5 m/s | 7.9 |
| 2011 🌧️ | 25.9°C | 22.4°C | 18.9°C | 33.6°C | 16.7°C | 39 mm | 66% | 5.3 m/s | 7.7 |
| 2010 | 24.9°C | 21.7°C | 18.4°C | 34.1°C | 14.7°C | 21 mm | 65% | 5.8 m/s | 7.8 |
| 2009 | 25.8°C | 21.9°C | 18.0°C | 34.5°C | 14.3°C | 1 mm | 61% | 5.7 m/s | 8.8 |
| 2008 | 23.1°C | 20.3°C | 17.6°C | 31.3°C | 15.3°C | 13 mm | 70% | 5.8 m/s | 8.6 |
| 2007 | 23.8°C | 20.5°C | 17.3°C | 35.4°C | 13.2°C | 38 mm | 66% | 5.9 m/s | 7.9 |
| 2006 | 26.0°C | 22.1°C | 18.3°C | 33.5°C | 14.6°C | 6 mm | 63% | 5.4 m/s | 8.5 |
| 2005 ❄️ | 20.0°C | 18.1°C | 16.2°C | 25.1°C | 13.8°C | 10 mm | 73% | 5.5 m/s | 8.1 |
| 2004 | 25.4°C | 21.7°C | 18.0°C | 36.3°C | 14.3°C | 4 mm | 65% | 5.4 m/s | 8.3 |
| 2003 | 23.9°C | 20.6°C | 17.3°C | 33.1°C | 14.0°C | 3 mm | 69% | 6 m/s | 8.6 |
| 2002 | 26.0°C | 22.2°C | 18.3°C | 35.3°C | 13.0°C | 3 mm | 64% | 5.4 m/s | 8.4 |
| 2001 | 23.1°C | 19.8°C | 16.6°C | 28.0°C | 13.9°C | 6 mm | 66% | 6 m/s | 8.5 |
| 2000 | 25.5°C | 21.9°C | 18.3°C | 34.5°C | 14.5°C | 1 mm | 64% | 5.9 m/s | 8.8 |
| 1999 | 27.2°C | 23.3°C | 19.4°C | 35.0°C | 15.0°C | 9 mm | 62% | 5.3 m/s | 8.4 |
| 1998 | 25.2°C | 21.9°C | 18.6°C | 33.3°C | 14.6°C | 12 mm | 66% | 5.5 m/s | 8.3 |
| 1997 | 25.6°C | 22.0°C | 18.5°C | 37.5°C | 15.4°C | 1 mm | 65% | 5.6 m/s | 8.7 |
| 1996 | 24.2°C | 20.7°C | 17.3°C | 33.4°C | 14.9°C | 17 mm | 65% | 6.3 m/s | 8.5 |
| 1995 | 24.4°C | 21.1°C | 17.7°C | 30.2°C | 14.0°C | 9 mm | 65% | 5.8 m/s | 8.2 |
| 1994 | 26.0°C | 22.3°C | 18.6°C | 34.9°C | 14.4°C | 0 mm | 62% | 5.5 m/s | 8.7 |
| 1993 | 25.0°C | 21.0°C | 17.0°C | 34.2°C | 14.2°C | 2 mm | 61% | 6 m/s | 8.6 |
| 1992 | 24.0°C | 20.6°C | 17.1°C | 32.3°C | 14.3°C | 6 mm | 66% | 5.8 m/s | 8.5 |
| 1991 | 24.0°C | 20.9°C | 17.7°C | 33.7°C | 14.9°C | 21 mm | 70% | 5.3 m/s | 8.2 |
| 1990 | 23.4°C | 20.6°C | 17.8°C | 33.7°C | 15.0°C | 6 mm | 66% | 5.9 m/s | 8.5 |
| 1989 | 23.4°C | 20.4°C | 17.4°C | 33.8°C | 15.1°C | 7 mm | 66% | 5.8 m/s | 8.3 |
| 1988 | 24.9°C | 21.4°C | 17.8°C | 30.2°C | 13.6°C | 7 mm | 65% | 5.6 m/s | 8.4 |
| 1987 | 24.3°C | 21.1°C | 17.9°C | 37.8°C | 13.7°C | 14 mm | 68% | 5.3 m/s | 8.2 |
| 1986 | 24.2°C | 20.7°C | 17.3°C | 31.7°C | 13.0°C | 14 mm | 63% | 5.7 m/s | 8.3 |
| 1985 | 22.3°C | 19.5°C | 16.7°C | 30.6°C | 14.2°C | 3 mm | 65% | 5.6 m/s | 8.4 |
| 1984 | 21.9°C | 19.3°C | 16.6°C | 29.0°C | 13.3°C | 14 mm | 67% | 5.6 m/s | 7.9 |
| 1983 | 24.8°C | 21.3°C | 17.9°C | 34.4°C | 14.0°C | 14 mm | 68% | 5.1 m/s | — |
| 1982 | 23.4°C | 21.0°C | 18.5°C | 31.1°C | 14.6°C | 8 mm | 71% | 5.3 m/s | — |
| 1981 | 23.2°C | 20.0°C | 16.8°C | 30.4°C | 13.8°C | 6 mm | 65% | 5.8 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 24.7°C with lows near 18°C (mean 21.4°C), based on 45 years of NASA POWER data.
December averages 10 mm of rainfall in Perth, one of the drier months. The wettest on record was 39 mm in 2011.
The hottest December reached 38.3°C in 2021. The coldest dipped to 13°C in 1986.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 2.4°C. Daytime highs moved from 23.1°C to 26.2°C and overnight lows from 17.3°C to 19°C over the same span.
December is one of the warmer months of the year in Perth and one of the drier months, so plan for around 24.7°C daytime highs and 18°C at night.
Not quite — December is the 9th coolest month in Perth, averaging 21.4°C.
For December in Perth, pack light layers you can adjust through the day, with typical highs of 24.7°C and lows of 18°C.
Relative humidity in December averages 65% — moderately humid.
Average wind speed in December is 5.6 m/s. The windiest December on record averaged 6.3 m/s (1996).
The wettest December on record was 2011 with 39 mm. On average, December sees 10 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 Perth 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.
