May is one of the warmer months of the year in Delta, with average highs near 15.5°C and lows around 9.6°C (mean 12.6°C). It is one of the drier months, averaging 66 mm of rainfall and 77% relative humidity across the period.
May is one of the warmer months of the year in Delta. Across 45 years of records, the warmest May in Delta was 2023 — when the month averaged 15°C — while the coldest was 1999 at 10.3°C. Typical May days reach 15.5°C with nights near 9.6°C. The long-term trend is warming, about 0.2°C per decade.
May is one of the drier months in Delta, averaging 66 mm of rainfall. The wettest May on record was 1984 with 134 mm, while the driest was 2018 at 10 mm.
Relative humidity in Delta during May averages 77%. The most humid May was 2025 at 83%, and the least humid was 1992 at 72%.
May receives about 5.1 kWh/m²/day of solar energy in Delta. The sunniest May was 2018 at 6.1 kWh/m²/day, and the cloudiest were 2011 and 2022 at 4.2.
Average wind speed in Delta during May is 1.3 m/s. The windiest May was 2025 at 1.7 m/s, while the calmest was 2015 at 1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 12.1°C | 12.9°C | 12.3°C | 13.1°C | 12.5°C | +0.4°C |
| Avg High | 15.1°C | 15.8°C | 15.1°C | 16.0°C | 15.4°C | +0.3°C |
| Avg Low | 9.0°C | 9.9°C | 9.3°C | 10.1°C | 9.7°C | +0.7°C |
| Avg Rain | 77 mm | 63 mm | 63 mm | 57 mm | 74 mm | -3 mm |
May temperatures in Delta have stayed relatively stable across the record.
May has ranged from a record low of 4.2°C (1999) to a record high of 28.3°C (2005).
Rainfall in May is one of the drier months, averaging 66 mm, with a wettest year of 134 mm.
A good time to visit Delta
May is a good time to visit Delta, with days averaging 15.5°C and nights around 9.6°C (mean 12.6°C, warmer than Delta's yearly average) and moderate rainfall. August and July 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 | 14.1°C | 11.3°C | 8.6°C | 21.2°C | 6.6°C | 75 mm | 83% | 1.7 m/s | 5.1 |
| 2024 | 14.9°C | 12.0°C | 9.0°C | 21.7°C | 6.2°C | 78 mm | 81% | 1.6 m/s | 5 |
| 2023 🔥 | 18.3°C | 15.0°C | 11.6°C | 27.6°C | 8.3°C | 34 mm | 78% | 1.1 m/s | 5.7 |
| 2022 | 13.0°C | 10.7°C | 8.4°C | 17.5°C | 5.7°C | 118 mm | 81% | 1.6 m/s | 4.2 |
| 2021 | 15.3°C | 12.5°C | 9.7°C | 21.0°C | 7.0°C | 43 mm | 77% | 1.3 m/s | 5.3 |
| 2020 | 16.6°C | 13.6°C | 10.6°C | 25.3°C | 6.1°C | 95 mm | 76% | 1.3 m/s | 5.2 |
| 2019 | 17.7°C | 14.6°C | 11.4°C | 23.6°C | 7.6°C | 39 mm | 77% | 1.1 m/s | 5.7 |
| 2018 | 17.8°C | 14.5°C | 11.2°C | 25.9°C | 8.3°C | 10 mm | 77% | 1.1 m/s | 6.1 |
| 2017 | 16.0°C | 13.0°C | 10.0°C | 24.7°C | 6.1°C | 84 mm | 77% | 1.2 m/s | 5.3 |
| 2016 | 17.3°C | 14.3°C | 11.3°C | 24.1°C | 8.8°C | 41 mm | 76% | 1.3 m/s | 5.3 |
| 2015 | 17.4°C | 14.4°C | 11.3°C | 22.5°C | 7.3°C | 17 mm | 79% | 1 m/s | 5.8 |
| 2014 | 16.2°C | 13.5°C | 10.7°C | 21.4°C | 7.8°C | 73 mm | 80% | 1.2 m/s | 5.1 |
| 2013 | 15.8°C | 12.9°C | 10.0°C | 24.1°C | 5.8°C | 75 mm | 79% | 1.1 m/s | 5.1 |
| 2012 | 14.4°C | 11.6°C | 8.7°C | 20.8°C | 5.8°C | 58 mm | 75% | 1.4 m/s | 5.4 |
| 2011 | 13.1°C | 10.6°C | 8.0°C | 17.8°C | 5.7°C | 93 mm | 81% | 1.3 m/s | 4.2 |
| 2010 | 14.0°C | 11.1°C | 8.3°C | 18.5°C | 4.9°C | 84 mm | 78% | 1.5 m/s | 4.9 |
| 2009 | 15.2°C | 11.9°C | 8.6°C | 22.1°C | 5.8°C | 70 mm | 76% | 1.3 m/s | 5.5 |
| 2008 | 15.4°C | 12.2°C | 9.0°C | 23.8°C | 5.2°C | 42 mm | 78% | 1.2 m/s | 4.8 |
| 2007 | 15.3°C | 12.2°C | 9.1°C | 23.9°C | 5.9°C | 42 mm | 76% | 1.2 m/s | 5.5 |
| 2006 | 15.7°C | 12.7°C | 9.7°C | 23.8°C | 5.7°C | 60 mm | 75% | 1.3 m/s | 5.3 |
| 2005 | 17.2°C | 14.2°C | 11.3°C | 28.3°C | 8.8°C | 80 mm | 79% | 1.4 m/s | 4.9 |
| 2004 | 16.0°C | 13.4°C | 10.7°C | 20.9°C | 8.3°C | 63 mm | 77% | 1.1 m/s | 5 |
| 2003 | 14.4°C | 11.8°C | 9.2°C | 20.1°C | 5.5°C | 50 mm | 78% | 1.2 m/s | 4.9 |
| 2002 | 13.9°C | 11.2°C | 8.4°C | 20.6°C | 4.2°C | 57 mm | 77% | 1.4 m/s | 4.8 |
| 2001 | 14.6°C | 11.7°C | 8.8°C | 23.1°C | 5.6°C | 61 mm | 75% | 1.4 m/s | 5.2 |
| 2000 | 13.8°C | 11.2°C | 8.7°C | 19.6°C | 5.7°C | 108 mm | 80% | 1.3 m/s | 4.5 |
| 1999 ❄️ | 13.1°C | 10.3°C | 7.6°C | 21.1°C | 4.2°C | 65 mm | 77% | 1.6 m/s | 5 |
| 1998 | 15.6°C | 12.9°C | 10.1°C | 23.3°C | 6.6°C | 86 mm | 81% | 1.3 m/s | 5.1 |
| 1997 | 17.2°C | 14.0°C | 10.8°C | 24.9°C | 5.8°C | 96 mm | 78% | 1.3 m/s | 5.1 |
| 1996 | 13.5°C | 11.0°C | 8.5°C | 18.1°C | 4.8°C | 82 mm | 78% | 1.5 m/s | 4.9 |
| 1995 | 17.6°C | 14.2°C | 10.8°C | 22.6°C | 7.8°C | 28 mm | 74% | 1.1 m/s | 6 |
| 1994 | 16.2°C | 13.2°C | 10.2°C | 20.8°C | 6.9°C | 43 mm | 75% | 1.3 m/s | 4.9 |
| 1993 | 17.6°C | 14.4°C | 11.2°C | 27.6°C | 6.5°C | 107 mm | 78% | 1.3 m/s | 5 |
| 1992 | 17.6°C | 14.2°C | 10.8°C | 24.1°C | 6.2°C | 15 mm | 72% | 1.2 m/s | 5.6 |
| 1991 | 14.8°C | 12.0°C | 9.2°C | 19.4°C | 7.2°C | 50 mm | 79% | 1.4 m/s | 4.7 |
| 1990 | 15.2°C | 12.3°C | 9.5°C | 19.0°C | 6.5°C | 54 mm | 79% | 1.5 m/s | 4.6 |
| 1989 | 15.5°C | 12.4°C | 9.3°C | 19.5°C | 5.5°C | 74 mm | 77% | 1.4 m/s | 4.9 |
| 1988 | 14.7°C | 11.7°C | 8.7°C | 23.0°C | 4.6°C | 116 mm | 78% | 1.4 m/s | 4.4 |
| 1987 | 15.7°C | 12.5°C | 9.2°C | 21.6°C | 7.1°C | 87 mm | 76% | 1.4 m/s | 5.3 |
| 1986 | 14.4°C | 11.6°C | 8.8°C | 24.1°C | 5.8°C | 110 mm | 80% | 1.4 m/s | 4.5 |
| 1985 | 15.4°C | 12.1°C | 8.8°C | 25.7°C | 4.9°C | 46 mm | 75% | 1.3 m/s | 4.7 |
| 1984 🌧️ | 13.0°C | 10.4°C | 7.7°C | 20.4°C | 5.7°C | 134 mm | 79% | 1.6 m/s | 4.3 |
| 1983 | 17.0°C | 13.8°C | 10.6°C | 27.1°C | 7.2°C | 41 mm | 75% | 1.3 m/s | — |
| 1982 | 15.4°C | 12.2°C | 9.0°C | 21.4°C | 5.1°C | 21 mm | 72% | 1.3 m/s | — |
| 1981 | 14.9°C | 12.1°C | 9.3°C | 19.5°C | 4.6°C | 65 mm | 78% | 1.3 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 15.5°C with lows near 9.6°C (mean 12.6°C), based on 45 years of NASA POWER data.
May averages 66 mm of rainfall in Delta, one of the drier months. The wettest on record was 134 mm in 1984.
The hottest May reached 28.3°C in 2005. The coldest dipped to 4.2°C in 1999.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 0.2°C. Daytime highs moved from 15.1°C to 15.1°C and overnight lows from 9.1°C to 9.5°C over the same span.
May is one of the warmer months of the year in Delta and one of the drier months, so plan for around 15.5°C daytime highs and 9.6°C at night.
Not quite — May is the 8th coolest month in Delta, averaging 12.6°C.
For May in Delta, pack light layers you can adjust through the day, with typical highs of 15.5°C and lows of 9.6°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 77% — quite humid.
Average wind speed in May is 1.3 m/s. The windiest May on record averaged 1.7 m/s (2025).
The wettest May on record was 1984 with 134 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 Delta 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.
