May is one of the cooler months of the year in Whyalla, with average highs near 19.7°C and lows around 11.5°C (mean 15.6°C). It is about average for rainfall, averaging 24 mm of rainfall and 66% relative humidity across the period.
May is one of the cooler months of the year in Whyalla. Across 45 years of records, the warmest May in Whyalla was 2013 — when the month averaged 17.1°C — while the coldest was 2006 at 13.9°C. Typical May days reach 19.7°C with nights near 11.5°C. The long-term May temperature trend is broadly flat.
May is about average for rainfall in Whyalla, averaging 24 mm of rainfall. The wettest May on record was 2010 with 60 mm, while the driest was 1996 at 3 mm.
Relative humidity in Whyalla during May averages 66%. The most humid May was 2009 at 73%, and the least humid was 2021 at 58%.
May receives about 3.1 kWh/m²/day of solar energy in Whyalla. The sunniest May was 2025 at 3.6 kWh/m²/day, and the cloudiest was 1997 at 2.8.
Average wind speed in Whyalla during May is 3.5 m/s. The windiest Mays were 1981, 2007 and 2016 at 4.2 m/s, while the calmest were 2008, 2009 and 2024 at 2.8 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 15.5°C | 15.6°C | 15.7°C | 15.7°C | 15.6°C | +0.1°C |
| Avg High | 19.6°C | 19.7°C | 19.9°C | 19.8°C | 19.8°C | +0.2°C |
| Avg Low | 11.4°C | 11.6°C | 11.6°C | 11.7°C | 11.3°C | -0.1°C |
| Avg Rain | 30 mm | 21 mm | 23 mm | 32 mm | 10 mm | -20 mm |
May temperatures in Whyalla have risen by about 0.4°C between 1981–1985 and 2021–2025.
May has ranged from a record low of 6.5°C (2017) to a record high of 28.5°C (2002).
Rainfall in May is about average for rainfall, averaging 24 mm, with a wettest year of 60 mm.
A good time to visit Whyalla
May is a good time to visit Whyalla, with days averaging 19.7°C and nights around 11.5°C (mean 15.6°C, cooler than Whyalla's yearly average) and low rainfall. March and December 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 | 21.0°C | 16.3°C | 11.6°C | 26.6°C | 7.2°C | 7 mm | 62% | 3.3 m/s | 3.6 |
| 2024 | 20.8°C | 16.0°C | 11.3°C | 23.8°C | 7.9°C | 6 mm | 62% | 2.8 m/s | 3.5 |
| 2023 | 19.2°C | 15.3°C | 11.4°C | 23.1°C | 9.6°C | 16 mm | 69% | 3.1 m/s | 3 |
| 2022 | 19.5°C | 15.5°C | 11.5°C | 23.7°C | 8.4°C | 19 mm | 69% | 3.3 m/s | 3.3 |
| 2021 | 20.2°C | 16.1°C | 12.0°C | 26.7°C | 6.6°C | 5 mm | 58% | 3.4 m/s | 3 |
| 2020 | 18.3°C | 14.1°C | 10.0°C | 23.1°C | 6.5°C | 8 mm | 66% | 4.1 m/s | 3.2 |
| 2019 | 19.9°C | 15.5°C | 11.2°C | 26.1°C | 9.5°C | 28 mm | 65% | 3.7 m/s | 3 |
| 2018 | 19.7°C | 15.8°C | 12.0°C | 26.3°C | 8.5°C | 13 mm | 66% | 3.7 m/s | 3 |
| 2017 | 20.1°C | 15.6°C | 11.2°C | 23.6°C | 6.5°C | 7 mm | 61% | 3.3 m/s | 3.3 |
| 2016 | 20.8°C | 16.5°C | 12.3°C | 26.3°C | 10.0°C | 22 mm | 65% | 4.2 m/s | 3 |
| 2015 | 18.9°C | 14.9°C | 11.0°C | 26.4°C | 8.2°C | 23 mm | 72% | 3.5 m/s | 3 |
| 2014 | 20.5°C | 16.7°C | 13.0°C | 25.4°C | 9.2°C | 47 mm | 70% | 3.3 m/s | 3 |
| 2013 🔥 | 21.2°C | 17.1°C | 13.0°C | 27.4°C | 9.0°C | 56 mm | 66% | 3.9 m/s | 3 |
| 2012 | 18.9°C | 14.7°C | 10.5°C | 27.1°C | 7.1°C | 32 mm | 70% | 3.4 m/s | 3 |
| 2011 | 18.1°C | 14.7°C | 11.3°C | 23.3°C | 6.8°C | 32 mm | 71% | 3.6 m/s | 3 |
| 2010 🌧️ | 19.7°C | 15.7°C | 11.8°C | 26.1°C | 8.0°C | 60 mm | 67% | 3.6 m/s | 2.9 |
| 2009 | 19.1°C | 15.3°C | 11.5°C | 22.4°C | 8.6°C | 12 mm | 73% | 2.8 m/s | 3 |
| 2008 | 20.3°C | 15.9°C | 11.5°C | 24.1°C | 9.6°C | 24 mm | 66% | 2.8 m/s | 3.3 |
| 2007 | 20.9°C | 16.4°C | 11.9°C | 24.4°C | 8.0°C | 19 mm | 68% | 4.2 m/s | 3.2 |
| 2006 ❄️ | 18.0°C | 13.9°C | 9.9°C | 22.2°C | 6.8°C | 17 mm | 71% | 3.3 m/s | 3.2 |
| 2005 | 21.2°C | 17.0°C | 12.8°C | 28.1°C | 7.9°C | 8 mm | 62% | 3.5 m/s | 3.2 |
| 2004 | 19.3°C | 15.2°C | 11.0°C | 22.3°C | 7.2°C | 18 mm | 65% | 3.2 m/s | 3.2 |
| 2003 | 20.4°C | 16.1°C | 11.8°C | 24.6°C | 8.4°C | 35 mm | 67% | 3.5 m/s | 3.1 |
| 2002 | 21.1°C | 17.0°C | 12.8°C | 28.5°C | 8.6°C | 38 mm | 59% | 3.5 m/s | 3.1 |
| 2001 | 19.6°C | 15.6°C | 11.6°C | 25.8°C | 6.6°C | 34 mm | 66% | 3.3 m/s | 3.2 |
| 2000 | 18.6°C | 14.9°C | 11.1°C | 24.0°C | 8.0°C | 28 mm | 70% | 3.7 m/s | 3.2 |
| 1999 | 20.6°C | 16.3°C | 11.9°C | 25.8°C | 8.3°C | 33 mm | 62% | 3.6 m/s | 2.9 |
| 1998 | 20.2°C | 15.9°C | 11.6°C | 24.6°C | 7.9°C | 6 mm | 64% | 3.2 m/s | 3.1 |
| 1997 | 19.1°C | 15.4°C | 11.8°C | 26.8°C | 7.5°C | 24 mm | 68% | 3 m/s | 2.8 |
| 1996 | 20.0°C | 15.7°C | 11.4°C | 25.9°C | 8.0°C | 3 mm | 66% | 2.9 m/s | 3.2 |
| 1995 | 18.2°C | 14.4°C | 10.6°C | 24.9°C | 7.6°C | 29 mm | 70% | 3.7 m/s | 3.1 |
| 1994 | 20.3°C | 16.0°C | 11.7°C | 27.0°C | 8.4°C | 7 mm | 62% | 4.1 m/s | 3.5 |
| 1993 | 20.4°C | 16.2°C | 12.1°C | 25.9°C | 8.1°C | 28 mm | 65% | 3.1 m/s | 3.1 |
| 1992 | 18.5°C | 14.9°C | 11.3°C | 25.2°C | 7.0°C | 40 mm | 70% | 3.3 m/s | 3.1 |
| 1991 | 19.5°C | 15.3°C | 11.2°C | 23.3°C | 8.7°C | 8 mm | 64% | 3.2 m/s | 3.2 |
| 1990 | 20.3°C | 16.3°C | 12.2°C | 27.0°C | 7.4°C | 34 mm | 68% | 4 m/s | 3.2 |
| 1989 | 19.0°C | 15.4°C | 11.7°C | 23.5°C | 9.9°C | 39 mm | 73% | 3.3 m/s | 3 |
| 1988 | 20.5°C | 16.7°C | 12.9°C | 27.5°C | 8.2°C | 37 mm | 69% | 3.7 m/s | 2.9 |
| 1987 | 18.9°C | 14.9°C | 11.0°C | 24.0°C | 6.9°C | 49 mm | 70% | 3.9 m/s | 3 |
| 1986 | 19.6°C | 15.4°C | 11.3°C | 24.0°C | 6.8°C | 22 mm | 65% | 3.5 m/s | 3.2 |
| 1985 | 19.5°C | 15.1°C | 10.7°C | 26.6°C | 7.0°C | 20 mm | 60% | 3.2 m/s | 3.4 |
| 1984 | 19.8°C | 15.6°C | 11.3°C | 25.5°C | 8.9°C | 18 mm | 65% | 3.5 m/s | 3.1 |
| 1983 | 19.3°C | 15.2°C | 11.0°C | 23.0°C | 7.9°C | 29 mm | 70% | 3.4 m/s | — |
| 1982 | 19.8°C | 15.6°C | 11.4°C | 25.1°C | 8.2°C | 17 mm | 63% | 3.6 m/s | — |
| 1981 | 19.7°C | 15.6°C | 11.5°C | 26.6°C | 7.4°C | 41 mm | 64% | 4.2 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 19.7°C with lows near 11.5°C (mean 15.6°C), based on 45 years of NASA POWER data.
May averages 24 mm of rainfall in Whyalla, about average for rainfall. The wettest on record was 60 mm in 2010.
The hottest May reached 28.5°C in 2002. The coldest dipped to 6.5°C in 2017.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 0.4°C. Daytime highs moved from 19.6°C to 20.1°C and overnight lows from 11.2°C to 11.6°C over the same span.
May is one of the cooler months of the year in Whyalla and about average for rainfall, so plan for around 19.7°C daytime highs and 11.5°C at night.
Not quite — May is the 5th coolest month in Whyalla, averaging 15.6°C.
For May in Whyalla, pack light layers you can adjust through the day, with typical highs of 19.7°C and lows of 11.5°C.
Relative humidity in May averages 66% — moderately humid.
Average wind speed in May is 3.5 m/s. The windiest May on record averaged 4.2 m/s (1981).
The wettest May on record was 2010 with 60 mm. On average, May sees 24 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 Whyalla 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.
