May is one of the cooler months of the year in Mount Barker, with average highs near 18°C and lows around 9.4°C (mean 13.7°C). It is a relatively wet time of year, averaging 50 mm of rainfall and 72% relative humidity across the period.
May is one of the cooler months of the year in Mount Barker. Across 45 years of records, the warmest May in Mount Barker was 2014 — when the month averaged 15°C — while the coldest were 2006 and 2020 at 12°C. Typical May days reach 18°C with nights near 9.4°C. The long-term May temperature trend is broadly flat.
May is a relatively wet time of year in Mount Barker, averaging 50 mm of rainfall. The wettest May on record was 1987 with 100 mm, while the driest was 2005 at 7 mm.
Relative humidity in Mount Barker during May averages 72%. The most humid May was 2009 at 80%, and the least humid was 2002 at 62%.
May receives about 2.6 kWh/m²/day of solar energy in Mount Barker. The sunniest Mays were 2024 and 2025 at 3.1 kWh/m²/day, and the cloudiest was 1997 at 2.2.
Average wind speed in Mount Barker during May is 2.4 m/s. The windiest May was 2016 at 3.2 m/s, while the calmest were 1996, 2009 and 2024, among others at 1.9 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 13.5°C | 13.6°C | 13.8°C | 14.0°C | 13.6°C | +0.1°C |
| Avg High | 17.7°C | 17.9°C | 18.1°C | 18.1°C | 18.2°C | +0.5°C |
| Avg Low | 9.3°C | 9.2°C | 9.5°C | 9.9°C | 8.9°C | -0.4°C |
| Avg Rain | 61 mm | 40 mm | 50 mm | 55 mm | 40 mm | -21 mm |
May temperatures in Mount Barker have risen by about 0.7°C between 1981–1985 and 2021–2025.
May has ranged from a record low of 2.6°C (1990) to a record high of 28.4°C (2005).
Rainfall in May is a relatively wet time of year, averaging 50 mm, with a wettest year of 100 mm.
A good time to visit Mount Barker
May is a good time to visit Mount Barker, with days averaging 18°C and nights around 9.4°C (mean 13.7°C, cooler than Mount Barker'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 | 19.7°C | 14.4°C | 9.1°C | 25.9°C | 3.3°C | 27 mm | 65% | 2.3 m/s | 3.1 |
| 2024 | 20.0°C | 14.2°C | 8.5°C | 23.2°C | 5.3°C | 13 mm | 66% | 1.9 m/s | 3.1 |
| 2023 | 17.1°C | 13.1°C | 9.2°C | 22.8°C | 4.0°C | 61 mm | 77% | 2.3 m/s | 2.6 |
| 2022 | 17.7°C | 13.5°C | 9.2°C | 22.3°C | 4.5°C | 65 mm | 75% | 2.4 m/s | 2.8 |
| 2021 | 18.7°C | 14.2°C | 9.7°C | 26.3°C | 3.0°C | 11 mm | 63% | 2.4 m/s | 2.6 |
| 2020 | 16.1°C | 12.0°C | 7.9°C | 20.9°C | 3.5°C | 65 mm | 75% | 2.8 m/s | 2.7 |
| 2019 | 18.1°C | 13.9°C | 9.8°C | 23.3°C | 7.4°C | 48 mm | 71% | 2.8 m/s | 2.6 |
| 2018 | 18.3°C | 14.3°C | 10.3°C | 25.4°C | 4.9°C | 33 mm | 70% | 2.6 m/s | 2.3 |
| 2017 | 18.2°C | 13.5°C | 8.8°C | 22.6°C | 4.5°C | 22 mm | 69% | 2.2 m/s | 2.7 |
| 2016 | 18.6°C | 14.9°C | 11.3°C | 22.9°C | 6.2°C | 61 mm | 72% | 3.2 m/s | 2.5 |
| 2015 | 17.1°C | 13.4°C | 9.6°C | 25.0°C | 4.5°C | 65 mm | 76% | 2.8 m/s | 2.6 |
| 2014 🔥 | 19.1°C | 15.0°C | 10.9°C | 24.2°C | 4.9°C | 67 mm | 74% | 2.3 m/s | 2.6 |
| 2013 | 19.2°C | 14.9°C | 10.5°C | 27.6°C | 6.1°C | 79 mm | 70% | 2.4 m/s | 2.6 |
| 2012 | 17.2°C | 13.1°C | 9.0°C | 25.8°C | 5.2°C | 71 mm | 76% | 2.3 m/s | 2.5 |
| 2011 | 16.8°C | 12.8°C | 8.9°C | 22.3°C | 4.3°C | 52 mm | 74% | 2.2 m/s | 2.4 |
| 2010 | 18.7°C | 14.1°C | 9.5°C | 24.2°C | 5.2°C | 57 mm | 71% | 2.3 m/s | 2.6 |
| 2009 | 17.7°C | 13.6°C | 9.5°C | 21.7°C | 5.3°C | 32 mm | 80% | 1.9 m/s | 2.4 |
| 2008 | 18.4°C | 14.1°C | 9.7°C | 23.4°C | 5.9°C | 61 mm | 74% | 2.1 m/s | 2.7 |
| 2007 | 18.6°C | 14.7°C | 10.9°C | 23.2°C | 6.9°C | 64 mm | 76% | 3 m/s | 2.5 |
| 2006 ❄️ | 16.0°C | 12.0°C | 8.0°C | 20.0°C | 3.5°C | 54 mm | 78% | 2.2 m/s | 2.4 |
| 2005 | 19.9°C | 14.9°C | 9.8°C | 28.4°C | 4.4°C | 7 mm | 67% | 2 m/s | 2.7 |
| 2004 | 17.4°C | 13.0°C | 8.6°C | 21.5°C | 4.2°C | 35 mm | 72% | 2.4 m/s | 2.7 |
| 2003 | 18.7°C | 14.1°C | 9.5°C | 23.1°C | 4.6°C | 64 mm | 72% | 2.2 m/s | 2.6 |
| 2002 | 19.5°C | 14.8°C | 10.1°C | 27.7°C | 4.1°C | 55 mm | 62% | 2.2 m/s | 2.7 |
| 2001 | 18.2°C | 13.8°C | 9.4°C | 25.8°C | 5.3°C | 67 mm | 73% | 2 m/s | 2.5 |
| 2000 | 16.7°C | 12.9°C | 9.0°C | 22.7°C | 5.1°C | 65 mm | 78% | 2.6 m/s | 2.5 |
| 1999 | 18.5°C | 14.2°C | 10.0°C | 24.8°C | 3.1°C | 76 mm | 70% | 2.6 m/s | 2.4 |
| 1998 | 18.4°C | 13.7°C | 9.0°C | 24.5°C | 4.0°C | 27 mm | 71% | 2.1 m/s | 2.5 |
| 1997 | 17.3°C | 13.2°C | 9.1°C | 26.6°C | 4.4°C | 60 mm | 76% | 2.2 m/s | 2.2 |
| 1996 | 18.4°C | 13.7°C | 9.0°C | 24.4°C | 5.6°C | 24 mm | 74% | 1.9 m/s | 2.6 |
| 1995 | 16.6°C | 12.7°C | 8.8°C | 21.0°C | 4.9°C | 55 mm | 76% | 2.4 m/s | 2.4 |
| 1994 | 17.8°C | 13.6°C | 9.3°C | 25.5°C | 4.6°C | 38 mm | 70% | 3.1 m/s | 2.7 |
| 1993 | 19.0°C | 14.3°C | 9.6°C | 25.9°C | 4.2°C | 35 mm | 68% | 2.2 m/s | 2.7 |
| 1992 | 16.7°C | 12.7°C | 8.8°C | 25.0°C | 3.7°C | 55 mm | 76% | 2 m/s | 2.6 |
| 1991 | 17.9°C | 13.3°C | 8.7°C | 21.9°C | 5.7°C | 16 mm | 71% | 1.9 m/s | 2.5 |
| 1990 | 18.7°C | 14.2°C | 9.7°C | 26.0°C | 2.6°C | 18 mm | 69% | 2.5 m/s | 2.7 |
| 1989 | 17.7°C | 13.7°C | 9.7°C | 22.2°C | 5.0°C | 83 mm | 78% | 2.4 m/s | 2.5 |
| 1988 | 19.1°C | 14.9°C | 10.7°C | 28.3°C | 5.8°C | 88 mm | 75% | 2.5 m/s | 2.4 |
| 1987 🌧️ | 17.0°C | 13.2°C | 9.4°C | 24.5°C | 5.2°C | 100 mm | 76% | 2.9 m/s | 2.5 |
| 1986 | 17.7°C | 13.3°C | 8.9°C | 22.7°C | 5.7°C | 40 mm | 74% | 2.3 m/s | 2.7 |
| 1985 | 17.4°C | 12.9°C | 8.4°C | 24.8°C | 3.1°C | 42 mm | 69% | 2.3 m/s | 2.7 |
| 1984 | 18.3°C | 13.8°C | 9.4°C | 23.9°C | 5.7°C | 45 mm | 68% | 2.4 m/s | 2.6 |
| 1983 | 17.5°C | 13.0°C | 8.6°C | 21.3°C | 3.4°C | 52 mm | 76% | 2.3 m/s | — |
| 1982 | 17.3°C | 13.1°C | 9.0°C | 22.6°C | 3.9°C | 43 mm | 70% | 2.5 m/s | — |
| 1981 | 17.3°C | 13.2°C | 9.2°C | 25.6°C | 3.6°C | 58 mm | 69% | 2.8 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 18°C with lows near 9.4°C (mean 13.7°C), based on 45 years of NASA POWER data.
May averages 50 mm of rainfall in Mount Barker, a relatively wet time of year. The wettest on record was 100 mm in 1987.
The hottest May reached 28.4°C in 2005. The coldest dipped to 2.6°C in 1990.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 0.7°C. Daytime highs moved from 17.6°C to 18.6°C and overnight lows from 8.9°C to 9.1°C over the same span.
May is one of the cooler months of the year in Mount Barker and a relatively wet time of year, so plan for around 18°C daytime highs and 9.4°C at night.
Not quite — May is the 5th coolest month in Mount Barker, averaging 13.7°C.
For May in Mount Barker, pack light layers you can adjust through the day, with typical highs of 18°C and lows of 9.4°C.
Relative humidity in May averages 72% — moderately humid.
Average wind speed in May is 2.4 m/s. The windiest May on record averaged 3.2 m/s (2016).
The wettest May on record was 1987 with 100 mm. On average, May sees 50 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 Mount Barker 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.
