May is one of the cooler months of the year in Colac, with average highs near 15.4°C and lows around 9.9°C (mean 12.7°C). It is about average for rainfall, averaging 66 mm of rainfall and 80% relative humidity across the period.
May is one of the cooler months of the year in Colac. Across 45 years of records, the warmest May in Colac was 2007 — when the month averaged 14.5°C — while the coldest was 1995 at 11.3°C. Typical May days reach 15.4°C with nights near 9.9°C. The long-term May temperature trend is broadly flat.
May is about average for rainfall in Colac, averaging 66 mm of rainfall. The wettest May on record was 1987 with 148 mm, while the driest was 2025 at 16 mm.
Relative humidity in Colac during May averages 80%. The most humid May was 1983 at 87%, and the least humid was 2025 at 72%.
May receives about 2.2 kWh/m²/day of solar energy in Colac. The sunniest May was 2025 at 2.6 kWh/m²/day, and the cloudiest was 1997 at 1.8.
Average wind speed in Colac during May is 2.4 m/s. The windiest Mays were 1994 and 2016 at 3 m/s, while the calmest was 1991 at 1.9 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 12.6°C | 12.3°C | 12.8°C | 12.7°C | 12.7°C | +0.1°C |
| Avg High | 15.4°C | 15.1°C | 15.5°C | 15.4°C | 15.6°C | +0.2°C |
| Avg Low | 9.8°C | 9.6°C | 10.1°C | 10.1°C | 9.8°C | 0°C |
| Avg Rain | 86 mm | 56 mm | 61 mm | 76 mm | 41 mm | -45 mm |
May temperatures in Colac have risen by about 0.5°C between 1981–1985 and 2021–2025.
May has ranged from a record low of 4.6°C (2000) to a record high of 24.6°C (2013).
Rainfall in May is about average for rainfall, averaging 66 mm, with a wettest year of 148 mm.
A good time to visit Colac
May is a good time to visit Colac, with days averaging 15.4°C and nights around 9.9°C (mean 12.7°C, cooler than Colac's yearly average) and moderate rainfall. February and January are marginally more temperate, but May still suits most travellers.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 17.2°C | 13.9°C | 10.5°C | 23.2°C | 6.1°C | 16 mm | 72% | 2.2 m/s | 2.6 |
| 2024 | 16.3°C | 13.4°C | 10.4°C | 19.2°C | 7.0°C | 25 mm | 79% | 2.1 m/s | 2.4 |
| 2023 | 14.9°C | 12.3°C | 9.7°C | 19.4°C | 7.6°C | 43 mm | 78% | 2.6 m/s | 2.2 |
| 2022 | 15.4°C | 12.7°C | 10.1°C | 19.9°C | 6.6°C | 34 mm | 81% | 2.1 m/s | 2.2 |
| 2021 | 15.4°C | 12.4°C | 9.4°C | 22.0°C | 4.8°C | 86 mm | 78% | 2.5 m/s | 2.2 |
| 2020 | 14.2°C | 11.5°C | 8.8°C | 18.0°C | 5.7°C | 43 mm | 81% | 2.5 m/s | 2.3 |
| 2019 | 15.9°C | 13.1°C | 10.3°C | 20.8°C | 7.2°C | 110 mm | 79% | 2.6 m/s | 2.2 |
| 2018 | 15.7°C | 13.2°C | 10.7°C | 22.1°C | 6.8°C | 62 mm | 76% | 2.8 m/s | 2 |
| 2017 | 14.9°C | 12.3°C | 9.6°C | 18.4°C | 7.0°C | 39 mm | 81% | 2.3 m/s | 2.2 |
| 2016 | 16.2°C | 13.5°C | 10.7°C | 20.4°C | 5.3°C | 66 mm | 75% | 3 m/s | 2.2 |
| 2015 | 15.1°C | 12.3°C | 9.5°C | 20.5°C | 6.6°C | 75 mm | 80% | 2.9 m/s | 2.2 |
| 2014 | 16.3°C | 13.5°C | 10.8°C | 21.2°C | 7.4°C | 52 mm | 82% | 2.2 m/s | 2.1 |
| 2013 | 15.7°C | 12.9°C | 10.1°C | 24.6°C | 7.7°C | 91 mm | 78% | 2.4 m/s | 2.2 |
| 2012 | 15.0°C | 12.4°C | 9.8°C | 21.2°C | 6.4°C | 113 mm | 80% | 2.6 m/s | 2.2 |
| 2011 | 13.8°C | 11.5°C | 9.2°C | 19.7°C | 7.2°C | 78 mm | 82% | 2.2 m/s | 2.1 |
| 2010 | 15.4°C | 12.7°C | 10.1°C | 19.8°C | 7.5°C | 72 mm | 82% | 2.2 m/s | 2.2 |
| 2009 | 15.5°C | 12.9°C | 10.3°C | 19.6°C | 8.2°C | 45 mm | 84% | 2.2 m/s | 2.2 |
| 2008 | 15.2°C | 12.5°C | 9.7°C | 19.7°C | 6.9°C | 58 mm | 81% | 2.1 m/s | 2.1 |
| 2007 🔥 | 17.3°C | 14.5°C | 11.7°C | 21.6°C | 8.6°C | 85 mm | 78% | 2.8 m/s | 2.2 |
| 2006 | 14.0°C | 11.4°C | 8.9°C | 17.3°C | 5.8°C | 80 mm | 85% | 2.4 m/s | 2 |
| 2005 | 16.0°C | 13.2°C | 10.3°C | 23.3°C | 8.0°C | 27 mm | 77% | 2.4 m/s | 2.2 |
| 2004 | 14.8°C | 12.1°C | 9.3°C | 18.5°C | 7.1°C | 63 mm | 81% | 2.6 m/s | 2.3 |
| 2003 | 16.4°C | 13.3°C | 10.3°C | 20.0°C | 6.6°C | 31 mm | 80% | 2 m/s | 2.4 |
| 2002 | 16.5°C | 13.6°C | 10.6°C | 24.2°C | 7.8°C | 73 mm | 79% | 2.2 m/s | 2.2 |
| 2001 | 14.8°C | 12.5°C | 10.2°C | 19.0°C | 8.1°C | 42 mm | 85% | 2 m/s | 2.2 |
| 2000 | 14.8°C | 12.3°C | 9.8°C | 18.5°C | 4.6°C | 110 mm | 81% | 2.8 m/s | 2.1 |
| 1999 | 16.3°C | 13.3°C | 10.2°C | 21.8°C | 5.9°C | 75 mm | 77% | 2.4 m/s | 2 |
| 1998 | 15.2°C | 12.5°C | 9.9°C | 20.2°C | 5.8°C | 46 mm | 80% | 2.3 m/s | 2 |
| 1997 | 14.5°C | 12.2°C | 9.9°C | 20.7°C | 6.7°C | 93 mm | 83% | 2.2 m/s | 1.8 |
| 1996 | 15.3°C | 12.2°C | 9.1°C | 21.1°C | 6.9°C | 20 mm | 82% | 2.1 m/s | 2 |
| 1995 ❄️ | 13.7°C | 11.3°C | 8.9°C | 18.1°C | 6.1°C | 54 mm | 86% | 2.1 m/s | 2.1 |
| 1994 | 14.7°C | 12.1°C | 9.5°C | 19.9°C | 5.7°C | 87 mm | 77% | 3 m/s | 2.2 |
| 1993 | 15.7°C | 12.5°C | 9.3°C | 21.9°C | 6.3°C | 38 mm | 79% | 2.2 m/s | 2.3 |
| 1992 | 14.5°C | 12.1°C | 9.8°C | 20.8°C | 5.8°C | 87 mm | 84% | 2 m/s | 2.2 |
| 1991 | 15.4°C | 12.6°C | 9.9°C | 18.6°C | 7.9°C | 30 mm | 83% | 1.9 m/s | 2.1 |
| 1990 | 15.3°C | 12.4°C | 9.5°C | 22.3°C | 5.9°C | 32 mm | 79% | 2.4 m/s | 2.3 |
| 1989 | 15.6°C | 13.1°C | 10.6°C | 19.6°C | 7.1°C | 86 mm | 85% | 2.3 m/s | 2.2 |
| 1988 | 16.8°C | 14.0°C | 11.3°C | 23.8°C | 7.6°C | 83 mm | 83% | 2 m/s | 2 |
| 1987 🌧️ | 14.9°C | 12.2°C | 9.4°C | 20.1°C | 4.8°C | 148 mm | 83% | 2.5 m/s | 2.1 |
| 1986 | 14.7°C | 12.2°C | 9.7°C | 19.2°C | 7.4°C | 96 mm | 85% | 2.1 m/s | 2.1 |
| 1985 | 15.4°C | 12.6°C | 9.7°C | 22.1°C | 5.7°C | 54 mm | 82% | 2.2 m/s | 2.4 |
| 1984 | 15.8°C | 12.4°C | 9.1°C | 21.0°C | 6.7°C | 43 mm | 79% | 2.1 m/s | 2.5 |
| 1983 | 14.8°C | 12.3°C | 9.7°C | 18.0°C | 5.7°C | 98 mm | 87% | 2.6 m/s | — |
| 1982 | 15.0°C | 12.1°C | 9.2°C | 20.3°C | 6.3°C | 79 mm | 76% | 2.7 m/s | — |
| 1981 | 15.7°C | 12.6°C | 9.6°C | 22.8°C | 7.0°C | 86 mm | 78% | 2.3 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 15.4°C with lows near 9.9°C (mean 12.7°C), based on 45 years of NASA POWER data.
May averages 66 mm of rainfall in Colac, about average for rainfall. The wettest on record was 148 mm in 1987.
The hottest May reached 24.6°C in 2013. The coldest dipped to 4.6°C in 2000.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 0.5°C. Daytime highs moved from 15.3°C to 15.8°C and overnight lows from 9.5°C to 10°C over the same span.
May is one of the cooler months of the year in Colac and about average for rainfall, so plan for around 15.4°C daytime highs and 9.9°C at night.
Not quite — May is the 5th coolest month in Colac, averaging 12.7°C.
For May in Colac, pack light layers you can adjust through the day, with typical highs of 15.4°C and lows of 9.9°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 80% — quite humid.
Average wind speed in May is 2.4 m/s. The windiest May on record averaged 3 m/s (1994).
The wettest May on record was 1987 with 148 mm. On average, May sees 66 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 May, 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 May specifically, along with year-by-year records and how the month has changed over the decades.
