December is one of the cooler months of the year in Perth, with average highs near 5.1°C and lows around 1.5°C (mean 3.3°C). It is about average for rainfall, averaging 87 mm of rainfall and 95% relative humidity across the period.
December is one of the cooler months of the year in Perth. Across 45 years of records, the warmest December in Perth was 2015 — when the month averaged 5.5°C — while the coldest was 1981 at -0.8°C. Typical December days reach 5.1°C with nights near 1.5°C. The long-term trend is warming, about 0.3°C per decade.
December is about average for rainfall in Perth, averaging 87 mm of rainfall. The wettest December on record was 2015 with 170 mm, while the driest was 2010 at 31 mm.
Relative humidity in Perth during December averages 95%. The most humid December was 2020 at 96%, and the least humid was 2001 at 93%.
December receives about 0.3 kWh/m²/day of solar energy in Perth. The sunniest Decembers were 2021, 2022 and 2024, among others at 0.4 kWh/m²/day, and the cloudiest were 2016, 2019 and 2023, among others at 0.3.
Average wind speed in Perth during December is 4.1 m/s. The windiest December was 2013 at 5.8 m/s, while the calmest was 2010 at 2.7 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 3.0°C | 2.8°C | 3.4°C | 3.4°C | 4.1°C | +1.1°C |
| Avg High | 4.8°C | 4.5°C | 5.2°C | 5.3°C | 5.8°C | +1°C |
| Avg Low | 1.2°C | 1.1°C | 1.7°C | 1.5°C | 2.4°C | +1.2°C |
| Avg Rain | 86 mm | 84 mm | 76 mm | 87 mm | 115 mm | +29 mm |
December temperatures in Perth have risen by about 1.6°C between 1981–1985 and 2021–2025.
December has ranged from a record low of -7.7°C (1981) to a record high of 12.5°C (1994).
Rainfall in December is about average for rainfall, averaging 87 mm, with a wettest year of 170 mm.
A quieter season to visit Perth
If your dates are flexible, the more temperate months of July and August tend to be the most comfortable for visiting Perth. That said, December — with days averaging 5.1°C and nights around 1.5°C (mean 3.3°C) and higher rainfall (87 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 | 7.0°C | 5.4°C | 3.8°C | 11.9°C | -2.0°C | 106 mm | 95% | 3.8 m/s | — |
| 2024 | 7.2°C | 5.3°C | 3.4°C | 11.3°C | -1.2°C | 98 mm | 94% | 4.8 m/s | 0.4 |
| 2023 | 5.9°C | 4.3°C | 2.6°C | 10.6°C | -1.7°C | 157 mm | 93% | 4.2 m/s | 0.3 |
| 2022 | 4.3°C | 2.5°C | 0.7°C | 10.2°C | -3.8°C | 90 mm | 95% | 3.5 m/s | 0.4 |
| 2021 | 5.2°C | 3.4°C | 1.6°C | 9.8°C | -0.9°C | 115 mm | 95% | 3.3 m/s | 0.4 |
| 2020 | 5.4°C | 3.7°C | 2.1°C | 10.4°C | -2.5°C | 124 mm | 96% | 3.8 m/s | 0.4 |
| 2019 | 6.2°C | 4.3°C | 2.4°C | 11.1°C | -1.2°C | 78 mm | 95% | 4.2 m/s | 0.3 |
| 2018 | 5.6°C | 3.9°C | 2.3°C | 9.9°C | -1.3°C | 109 mm | 96% | 3.5 m/s | 0.4 |
| 2017 | 4.7°C | 2.9°C | 1.0°C | 11.1°C | -2.6°C | 60 mm | 95% | 3.9 m/s | 0.4 |
| 2016 | 7.0°C | 5.2°C | 3.4°C | 11.8°C | 0.9°C | 56 mm | 95% | 4.3 m/s | 0.3 |
| 2015 🔥 🌧️ | 7.7°C | 5.5°C | 3.3°C | 12.1°C | -1.5°C | 170 mm | 94% | 5.3 m/s | 0.3 |
| 2014 | 4.7°C | 2.8°C | 1.0°C | 9.8°C | -1.6°C | 41 mm | 95% | 4.5 m/s | 0.4 |
| 2013 | 6.9°C | 4.8°C | 2.8°C | 10.6°C | -1.6°C | 99 mm | 93% | 5.8 m/s | 0.3 |
| 2012 | 4.1°C | 2.4°C | 0.7°C | 9.7°C | -3.9°C | 153 mm | 95% | 4.2 m/s | 0.3 |
| 2011 | 5.2°C | 3.2°C | 1.1°C | 10.7°C | -2.0°C | 72 mm | 94% | 5.3 m/s | 0.4 |
| 2010 | 1.1°C | -0.7°C | -2.5°C | 4.8°C | -6.8°C | 31 mm | 95% | 2.7 m/s | 0.4 |
| 2009 | 3.1°C | 1.5°C | -0.2°C | 7.7°C | -4.5°C | 58 mm | 95% | 2.8 m/s | 0.3 |
| 2008 | 4.5°C | 2.7°C | 0.9°C | 9.9°C | -2.5°C | 76 mm | 95% | 3.6 m/s | 0.3 |
| 2007 | 5.3°C | 3.3°C | 1.2°C | 11.1°C | -2.7°C | 66 mm | 95% | 3.7 m/s | 0.4 |
| 2006 | 6.5°C | 4.4°C | 2.4°C | 11.3°C | -1.0°C | 86 mm | 95% | 4.6 m/s | 0.4 |
| 2005 | 5.8°C | 3.9°C | 2.1°C | 10.0°C | -1.3°C | 70 mm | 95% | 3.4 m/s | 0.4 |
| 2004 | 6.4°C | 4.4°C | 2.4°C | 10.3°C | -2.1°C | 41 mm | 95% | 4.5 m/s | 0.4 |
| 2003 | 5.6°C | 3.6°C | 1.7°C | 9.8°C | -2.7°C | 83 mm | 95% | 3.8 m/s | 0.3 |
| 2002 | 5.1°C | 3.9°C | 2.7°C | 9.4°C | -1.3°C | 95 mm | 94% | 3.2 m/s | 0.3 |
| 2001 | 4.6°C | 2.6°C | 0.6°C | 9.8°C | -3.7°C | 49 mm | 93% | 3.5 m/s | 0.4 |
| 2000 | 5.1°C | 4.0°C | 2.8°C | 10.7°C | -1.9°C | 136 mm | 94% | 4.1 m/s | 0.3 |
| 1999 | 3.7°C | 1.9°C | 0.1°C | 10.2°C | -5.1°C | 120 mm | 95% | 4.8 m/s | 0.3 |
| 1998 | 6.0°C | 4.0°C | 2.0°C | 11.6°C | -2.1°C | 81 mm | 96% | 4.3 m/s | 0.3 |
| 1997 | 5.9°C | 4.3°C | 2.8°C | 10.5°C | -1.0°C | 124 mm | 95% | 4.1 m/s | 0.3 |
| 1996 | 3.4°C | 2.0°C | 0.6°C | 7.3°C | -3.8°C | 71 mm | 94% | 3.6 m/s | 0.4 |
| 1995 | 2.9°C | 1.4°C | -0.1°C | 8.9°C | -7.7°C | 52 mm | 93% | 3.4 m/s | 0.3 |
| 1994 | 5.9°C | 4.1°C | 2.4°C | 12.5°C | -1.6°C | 83 mm | 95% | 4.9 m/s | 0.3 |
| 1993 | 3.6°C | 1.8°C | 0.0°C | 9.9°C | -3.3°C | 96 mm | 95% | 4.3 m/s | 0.3 |
| 1992 | 3.7°C | 2.2°C | 0.7°C | 8.5°C | -3.6°C | 96 mm | 96% | 3.8 m/s | 0.3 |
| 1991 | 5.5°C | 3.5°C | 1.4°C | 10.1°C | -1.7°C | 44 mm | 95% | 3.9 m/s | 0.3 |
| 1990 | 4.6°C | 2.7°C | 0.7°C | 9.8°C | -1.9°C | 74 mm | 94% | 4.5 m/s | 0.3 |
| 1989 | 3.6°C | 2.0°C | 0.5°C | 9.3°C | -3.4°C | 58 mm | 95% | 3 m/s | 0.4 |
| 1988 | 7.2°C | 5.3°C | 3.5°C | 10.9°C | -0.2°C | 38 mm | 93% | 5 m/s | 0.3 |
| 1987 | 5.7°C | 4.1°C | 2.5°C | 10.4°C | -1.9°C | 68 mm | 94% | 3.6 m/s | 0.3 |
| 1986 | 4.7°C | 2.8°C | 0.8°C | 10.4°C | -1.8°C | 146 mm | 95% | 4.7 m/s | 0.3 |
| 1985 | 5.5°C | 3.8°C | 2.1°C | 11.5°C | -6.1°C | 119 mm | 95% | 4.2 m/s | 0.3 |
| 1984 | 5.8°C | 4.1°C | 2.4°C | 10.1°C | -1.5°C | 86 mm | 95% | 3.8 m/s | 0.3 |
| 1983 | 6.2°C | 4.1°C | 2.1°C | 11.0°C | -1.8°C | 92 mm | 94% | 4.8 m/s | — |
| 1982 | 3.7°C | 1.7°C | -0.3°C | 8.8°C | -4.2°C | 90 mm | 95% | 4.2 m/s | — |
| 1981 ❄️ | 1.0°C | -0.8°C | -2.6°C | 9.2°C | -7.7°C | 82 mm | 94% | 3.2 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 5.1°C with lows near 1.5°C (mean 3.3°C), based on 45 years of NASA POWER data.
December averages 87 mm of rainfall in Perth, about average for rainfall. The wettest on record was 170 mm in 2015.
The hottest December reached 12.5°C in 1994. The coldest dipped to -7.7°C in 1981.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 1.6°C. Daytime highs moved from 4.4°C to 5.9°C and overnight lows from 0.7°C to 2.4°C over the same span.
December is one of the cooler months of the year in Perth and about average for rainfall, so plan for around 5.1°C daytime highs and 1.5°C at night.
Not quite — December is the 3rd coolest month in Perth, averaging 3.3°C.
For December in Perth, pack warm layers and a jacket for chilly mornings, with typical highs of 5.1°C and lows of 1.5°C. Bring an umbrella or light rain jacket too.
Relative humidity in December averages 95% — quite humid.
Average wind speed in December is 4.1 m/s. The windiest December on record averaged 5.8 m/s (2013).
The wettest December on record was 2015 with 170 mm. On average, December sees 87 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.
