December is one of the warmer months of the year in Colac, with average highs near 21.1°C and lows around 12.1°C (mean 16.6°C). It is about average for rainfall, averaging 53 mm of rainfall and 70% relative humidity across the period.
December is one of the warmer months of the year in Colac. Across 45 years of records, the warmest December in Colac was 2015 — when the month averaged 19.1°C — while the coldest was 2001 at 13.8°C. Typical December days reach 21.1°C with nights near 12.1°C. The long-term trend is warming, about 0.2°C per decade.
December is about average for rainfall in Colac, averaging 53 mm of rainfall. The wettest December on record was 1985 with 132 mm, while the driest was 1983 at 11 mm.
Relative humidity in Colac during December averages 70%. The most humid December was 1992 at 82%, and the least humid was 2015 at 61%.
December receives about 6.8 kWh/m²/day of solar energy in Colac. The sunniest December was 2015 at 7.7 kWh/m²/day, and the cloudiest was 2001 at 5.5.
Average wind speed in Colac during December is 2.5 m/s. The windiest December was 1984 at 3 m/s, while the calmest was 1988 at 2.1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 16.3°C | 16.1°C | 16.7°C | 17.3°C | 16.5°C | +0.2°C |
| Avg High | 20.8°C | 20.4°C | 21.3°C | 21.9°C | 21.0°C | +0.2°C |
| Avg Low | 11.8°C | 11.8°C | 12.2°C | 12.6°C | 12.1°C | +0.3°C |
| Avg Rain | 61 mm | 57 mm | 56 mm | 44 mm | 47 mm | -14 mm |
December temperatures in Colac have risen by about 0.4°C between 1981–1985 and 2021–2025.
December has ranged from a record low of 7.3°C (1995) to a record high of 38.3°C (2019).
Rainfall in December is about average for rainfall, averaging 53 mm, with a wettest year of 132 mm.
One of the best times to visit Colac
December is one of the best times to visit Colac. Expect days averaging 21.1°C and nights around 12.1°C (mean 16.6°C) — warmer than Colac's yearly average — with moderate rainfall (53 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 | 20.9°C | 16.1°C | 11.3°C | 30.7°C | 9.0°C | 30 mm | 66% | 2.6 m/s | — |
| 2024 | 22.9°C | 18.0°C | 13.1°C | 35.5°C | 10.2°C | 28 mm | 67% | 2.5 m/s | 7 |
| 2023 | 20.7°C | 16.9°C | 13.1°C | 32.3°C | 10.9°C | 106 mm | 75% | 2.7 m/s | 6.2 |
| 2022 | 20.3°C | 16.1°C | 11.9°C | 33.2°C | 8.8°C | 44 mm | 73% | 2.4 m/s | 7.3 |
| 2021 | 21.4°C | 16.7°C | 12.0°C | 32.5°C | 9.1°C | 22 mm | 68% | 2.4 m/s | 7.5 |
| 2020 | 19.6°C | 15.4°C | 11.3°C | 31.5°C | 8.9°C | 54 mm | 69% | 2.7 m/s | 6.4 |
| 2019 | 22.1°C | 17.1°C | 12.1°C | 38.3°C | 7.9°C | 13 mm | 67% | 2.7 m/s | 7.4 |
| 2018 | 23.7°C | 18.8°C | 13.9°C | 33.5°C | 10.6°C | 63 mm | 68% | 2.2 m/s | 6.8 |
| 2017 | 22.1°C | 17.8°C | 13.4°C | 33.2°C | 9.8°C | 47 mm | 69% | 2.4 m/s | 6.6 |
| 2016 | 22.7°C | 17.6°C | 12.4°C | 32.7°C | 8.9°C | 33 mm | 65% | 2.3 m/s | 6.9 |
| 2015 🔥 | 24.6°C | 19.1°C | 13.5°C | 38.1°C | 9.7°C | 27 mm | 61% | 2.3 m/s | 7.7 |
| 2014 | 21.0°C | 16.7°C | 12.5°C | 29.7°C | 9.5°C | 45 mm | 71% | 2.4 m/s | 6.7 |
| 2013 | 20.5°C | 16.0°C | 11.6°C | 32.3°C | 7.6°C | 53 mm | 74% | 2.3 m/s | 7 |
| 2012 | 21.3°C | 16.7°C | 12.1°C | 31.8°C | 9.4°C | 46 mm | 69% | 2.5 m/s | 7 |
| 2011 | 21.4°C | 17.1°C | 12.9°C | 30.0°C | 9.9°C | 28 mm | 71% | 2.4 m/s | 7.2 |
| 2010 | 19.7°C | 15.8°C | 11.9°C | 32.1°C | 9.3°C | 80 mm | 76% | 2.4 m/s | 6.8 |
| 2009 | 21.8°C | 17.0°C | 12.2°C | 32.9°C | 9.3°C | 60 mm | 68% | 2.3 m/s | 7.1 |
| 2008 | 18.8°C | 15.1°C | 11.4°C | 25.5°C | 8.3°C | 107 mm | 73% | 2.6 m/s | 6.4 |
| 2007 | 22.7°C | 17.8°C | 13.0°C | 35.3°C | 10.0°C | 77 mm | 68% | 2.3 m/s | 6.8 |
| 2006 | 21.1°C | 16.2°C | 11.3°C | 33.4°C | 9.0°C | 22 mm | 63% | 2.5 m/s | 7.5 |
| 2005 | 23.5°C | 18.1°C | 12.8°C | 35.1°C | 10.7°C | 44 mm | 62% | 2.7 m/s | 6.9 |
| 2004 | 20.8°C | 16.7°C | 12.6°C | 31.2°C | 9.4°C | 56 mm | 73% | 2.5 m/s | 6.9 |
| 2003 | 23.4°C | 18.2°C | 13.0°C | 34.6°C | 10.1°C | 43 mm | 66% | 2.3 m/s | 7 |
| 2002 | 21.1°C | 16.6°C | 12.2°C | 31.6°C | 8.8°C | 41 mm | 70% | 2.7 m/s | 6.4 |
| 2001 ❄️ | 17.2°C | 13.8°C | 10.5°C | 28.1°C | 8.6°C | 73 mm | 77% | 2.6 m/s | 5.5 |
| 2000 | 22.1°C | 17.3°C | 12.5°C | 34.9°C | 9.5°C | 33 mm | 66% | 2.6 m/s | 7.4 |
| 1999 | 20.8°C | 16.6°C | 12.4°C | 31.8°C | 9.8°C | 63 mm | 69% | 2.7 m/s | 6.8 |
| 1998 | 21.4°C | 16.9°C | 12.4°C | 36.7°C | 9.5°C | 43 mm | 70% | 2.6 m/s | 6.6 |
| 1997 | 20.4°C | 16.2°C | 12.0°C | 29.6°C | 10.0°C | 18 mm | 70% | 2.6 m/s | 6.8 |
| 1996 | 19.3°C | 14.7°C | 10.2°C | 29.8°C | 8.0°C | 38 mm | 68% | 2.4 m/s | 7 |
| 1995 | 18.2°C | 14.2°C | 10.2°C | 26.7°C | 7.3°C | 58 mm | 73% | 2.6 m/s | 6.4 |
| 1994 | 23.1°C | 17.9°C | 12.6°C | 33.1°C | 8.0°C | 30 mm | 64% | 2.2 m/s | 7.5 |
| 1993 | 19.8°C | 15.5°C | 11.2°C | 28.9°C | 8.6°C | 104 mm | 73% | 2.6 m/s | 6.5 |
| 1992 | 19.5°C | 16.1°C | 12.8°C | 25.6°C | 9.4°C | 104 mm | 82% | 2.5 m/s | 5.7 |
| 1991 | 19.5°C | 15.5°C | 11.4°C | 30.2°C | 8.2°C | 80 mm | 74% | 2.3 m/s | 6.5 |
| 1990 | 21.9°C | 17.1°C | 12.3°C | 31.5°C | 9.0°C | 34 mm | 70% | 2.7 m/s | 6.8 |
| 1989 | 21.6°C | 16.9°C | 12.3°C | 31.4°C | 9.6°C | 32 mm | 69% | 2.6 m/s | 7.4 |
| 1988 | 21.9°C | 17.3°C | 12.6°C | 31.5°C | 9.7°C | 60 mm | 71% | 2.1 m/s | 6.7 |
| 1987 | 19.8°C | 15.5°C | 11.2°C | 28.8°C | 8.0°C | 85 mm | 71% | 2.5 m/s | 6.8 |
| 1986 | 19.1°C | 14.9°C | 10.7°C | 29.5°C | 8.5°C | 102 mm | 73% | 2.6 m/s | 6.2 |
| 1985 🌧️ | 19.8°C | 16.0°C | 12.2°C | 25.2°C | 9.6°C | 132 mm | 78% | 2.5 m/s | 6.2 |
| 1984 | 19.4°C | 15.3°C | 11.2°C | 26.9°C | 9.1°C | 59 mm | 72% | 3 m/s | 6.8 |
| 1983 | 21.9°C | 17.2°C | 12.6°C | 33.0°C | 9.5°C | 11 mm | 66% | 2.2 m/s | — |
| 1982 | 21.9°C | 16.8°C | 11.7°C | 31.4°C | 8.3°C | 44 mm | 65% | 2.4 m/s | — |
| 1981 | 21.9°C | 16.9°C | 12.0°C | 33.4°C | 9.1°C | 26 mm | 66% | 2.4 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 21.1°C with lows near 12.1°C (mean 16.6°C), based on 45 years of NASA POWER data.
December averages 53 mm of rainfall in Colac, about average for rainfall. The wettest on record was 132 mm in 1985.
The hottest December reached 38.3°C in 2019. The coldest dipped to 7.3°C in 1995.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 0.4°C. Daytime highs moved from 21°C to 21.2°C and overnight lows from 11.9°C to 12.3°C over the same span.
December is one of the warmer months of the year in Colac and about average for rainfall, so plan for around 21.1°C daytime highs and 12.1°C at night.
Not quite — December is the 9th coolest month in Colac, averaging 16.6°C.
For December in Colac, pack light layers you can adjust through the day, with typical highs of 21.1°C and lows of 12.1°C. Bring an umbrella or light rain jacket too.
Relative humidity in December averages 70% — moderately humid.
Average wind speed in December is 2.5 m/s. The windiest December on record averaged 3 m/s (1984).
The wettest December on record was 1985 with 132 mm. On average, December sees 53 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 Colac 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.
