May is one of the warmer months of the year in Olympia, with average highs near 16.9°C and lows around 7.1°C (mean 12°C). It is one of the drier months, averaging 82 mm of rainfall and 83% relative humidity across the period.
May is one of the warmer months of the year in Olympia. Across 45 years of records, the warmest May in Olympia was 2023 — when the month averaged 14.6°C — while the coldest were 1999 and 2011 at 9.6°C. Typical May days reach 16.9°C with nights near 7.1°C. The long-term trend is warming, about 0.2°C per decade.
May is one of the drier months in Olympia, averaging 82 mm of rainfall. The wettest May on record was 1984 with 158 mm, while the driest was 1992 at 13 mm.
Relative humidity in Olympia during May averages 83%. The most humid May was 1998 at 86%, and the least humid was 1992 at 77%.
May receives about 5.1 kWh/m²/day of solar energy in Olympia. The sunniest May was 2023 at 6 kWh/m²/day, and the cloudiest were 1988 and 1991 at 4.3.
Average wind speed in Olympia during May is 0.2 m/s. The windiest Mays were 2023, 2024 and 2025, among others at 0.2 m/s, while the calmest were 2023, 2024 and 2025, among others at 0.2 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 11.6°C | 12.0°C | 11.7°C | 12.4°C | 12.1°C | +0.5°C |
| Avg High | 16.6°C | 16.9°C | 16.6°C | 17.3°C | 17.0°C | +0.4°C |
| Avg Low | 6.7°C | 7.1°C | 6.9°C | 7.5°C | 7.2°C | +0.5°C |
| Avg Rain | 88 mm | 82 mm | 77 mm | 80 mm | 81 mm | -7 mm |
May temperatures in Olympia have risen by about 0.5°C between 1981–1985 and 2021–2025.
May has ranged from a record low of -0.4°C (1999) to a record high of 35.3°C (1983).
Rainfall in May is one of the drier months, averaging 82 mm, with a wettest year of 158 mm.
A good time to visit Olympia
May is a good time to visit Olympia, with days averaging 16.9°C and nights around 7.1°C (mean 12°C, warmer than Olympia's yearly average) and higher 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 | 16.6°C | 11.7°C | 6.7°C | 24.4°C | 3.6°C | 55 mm | 83% | 0.2 m/s | 5.8 |
| 2024 | 16.2°C | 11.5°C | 6.9°C | 30.1°C | 4.1°C | 83 mm | 84% | 0.2 m/s | 5.4 |
| 2023 🔥 | 20.1°C | 14.6°C | 9.0°C | 28.2°C | 5.8°C | 34 mm | 80% | 0.2 m/s | 6 |
| 2022 | 14.1°C | 10.0°C | 5.9°C | 21.2°C | 2.4°C | 147 mm | 86% | 0.2 m/s | 4.5 |
| 2021 | 17.2°C | 12.1°C | 7.0°C | 24.6°C | 2.4°C | 61 mm | 82% | 0.2 m/s | 5.6 |
| 2020 | 17.8°C | 12.7°C | 7.7°C | 30.2°C | 3.1°C | 108 mm | 83% | 0.2 m/s | 5.2 |
| 2019 | 19.2°C | 13.8°C | 8.4°C | 29.1°C | 3.6°C | 37 mm | 81% | 0.2 m/s | 5.5 |
| 2018 | 19.3°C | 13.9°C | 8.6°C | 28.7°C | 5.9°C | 16 mm | 81% | 0.2 m/s | 5.8 |
| 2017 | 17.9°C | 12.7°C | 7.6°C | 30.2°C | 2.8°C | 94 mm | 82% | 0.2 m/s | 5.5 |
| 2016 | 18.4°C | 13.4°C | 8.4°C | 27.6°C | 5.8°C | 35 mm | 81% | 0.2 m/s | 5.4 |
| 2015 | 18.3°C | 13.4°C | 8.4°C | 25.5°C | 5.0°C | 30 mm | 83% | 0.2 m/s | 5.4 |
| 2014 | 18.0°C | 13.2°C | 8.4°C | 26.0°C | 4.2°C | 119 mm | 84% | 0.2 m/s | 5.2 |
| 2013 | 17.4°C | 12.6°C | 7.7°C | 25.0°C | 1.7°C | 115 mm | 84% | 0.2 m/s | 5.1 |
| 2012 | 16.0°C | 10.9°C | 5.8°C | 25.3°C | 0.3°C | 95 mm | 81% | 0.2 m/s | 5.4 |
| 2011 | 13.9°C | 9.6°C | 5.4°C | 18.6°C | 2.8°C | 122 mm | 84% | 0.2 m/s | 4.7 |
| 2010 | 14.2°C | 10.1°C | 5.9°C | 20.7°C | 2.2°C | 137 mm | 85% | 0.2 m/s | 4.8 |
| 2009 | 16.9°C | 11.6°C | 6.4°C | 24.0°C | 2.9°C | 128 mm | 82% | 0.2 m/s | 5.7 |
| 2008 | 16.2°C | 11.6°C | 6.9°C | 28.7°C | 1.6°C | 38 mm | 83% | 0.2 m/s | 4.6 |
| 2007 | 17.3°C | 11.8°C | 6.2°C | 27.0°C | 1.9°C | 44 mm | 81% | 0.2 m/s | 5.8 |
| 2006 | 17.3°C | 12.2°C | 7.1°C | 25.3°C | 2.0°C | 75 mm | 81% | 0.2 m/s | 5.5 |
| 2005 | 18.1°C | 13.4°C | 8.8°C | 34.3°C | 5.7°C | 130 mm | 84% | 0.2 m/s | 4.9 |
| 2004 | 17.0°C | 12.5°C | 8.0°C | 21.6°C | 5.5°C | 78 mm | 84% | 0.2 m/s | 4.6 |
| 2003 | 15.7°C | 11.0°C | 6.3°C | 25.8°C | 1.8°C | 43 mm | 83% | 0.2 m/s | 5.1 |
| 2002 | 15.1°C | 10.5°C | 5.9°C | 24.0°C | -0.4°C | 60 mm | 82% | 0.2 m/s | 4.9 |
| 2001 | 17.1°C | 11.8°C | 6.6°C | 31.1°C | 2.2°C | 72 mm | 80% | 0.2 m/s | 5.8 |
| 2000 | 14.9°C | 10.7°C | 6.6°C | 22.1°C | 1.9°C | 99 mm | 85% | 0.2 m/s | 4.9 |
| 1999 ❄️ | 14.2°C | 9.6°C | 5.0°C | 25.2°C | -0.4°C | 91 mm | 83% | 0.2 m/s | 5.3 |
| 1998 | 15.8°C | 11.5°C | 7.2°C | 25.6°C | 3.2°C | 82 mm | 86% | 0.2 m/s | 4.7 |
| 1997 | 18.7°C | 13.7°C | 8.7°C | 27.4°C | 3.4°C | 111 mm | 83% | 0.2 m/s | 5.3 |
| 1996 | 14.5°C | 10.0°C | 5.6°C | 20.9°C | 0.9°C | 112 mm | 83% | 0.2 m/s | 4.6 |
| 1995 | 18.7°C | 13.3°C | 7.8°C | 24.6°C | 4.0°C | 40 mm | 80% | 0.2 m/s | 5.6 |
| 1994 | 17.7°C | 12.7°C | 7.6°C | 25.1°C | 4.0°C | 72 mm | 82% | 0.2 m/s | 4.8 |
| 1993 | 18.7°C | 13.7°C | 8.7°C | 26.0°C | 2.5°C | 133 mm | 84% | 0.2 m/s | 4.4 |
| 1992 | 20.1°C | 13.8°C | 7.4°C | 31.7°C | 2.4°C | 13 mm | 77% | 0.2 m/s | 5.8 |
| 1991 | 15.2°C | 10.7°C | 6.3°C | 20.7°C | 3.0°C | 81 mm | 83% | 0.2 m/s | 4.3 |
| 1990 | 15.8°C | 11.2°C | 6.6°C | 23.6°C | 3.6°C | 87 mm | 84% | 0.2 m/s | 4.6 |
| 1989 | 17.0°C | 11.8°C | 6.7°C | 23.8°C | 4.2°C | 71 mm | 82% | 0.2 m/s | 4.6 |
| 1988 | 15.9°C | 11.1°C | 6.4°C | 28.1°C | 2.2°C | 138 mm | 84% | 0.2 m/s | 4.3 |
| 1987 | 17.9°C | 12.7°C | 7.4°C | 28.9°C | 4.9°C | 101 mm | 80% | 0.2 m/s | 5.3 |
| 1986 | 16.1°C | 11.4°C | 6.8°C | 29.2°C | 3.2°C | 113 mm | 84% | 0.2 m/s | 4.4 |
| 1985 | 16.6°C | 11.4°C | 6.3°C | 25.4°C | 1.5°C | 52 mm | 82% | 0.2 m/s | 5 |
| 1984 🌧️ | 14.2°C | 9.9°C | 5.6°C | 27.5°C | 2.6°C | 158 mm | 84% | 0.2 m/s | 4.9 |
| 1983 | 18.8°C | 13.4°C | 7.9°C | 35.3°C | 4.4°C | 65 mm | 81% | 0.2 m/s | — |
| 1982 | 16.9°C | 11.5°C | 6.1°C | 24.5°C | 3.3°C | 21 mm | 78% | 0.2 m/s | — |
| 1981 | 15.8°C | 11.2°C | 6.7°C | 23.7°C | 2.8°C | 74 mm | 83% | 0.2 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 16.9°C with lows near 7.1°C (mean 12°C), based on 45 years of NASA POWER data.
May averages 82 mm of rainfall in Olympia, one of the drier months. The wettest on record was 158 mm in 1984.
The hottest May reached 35.3°C in 1983. The coldest dipped to -0.4°C in 1999.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 0.5°C. Daytime highs moved from 16.5°C to 16.8°C and overnight lows from 6.5°C to 7.1°C over the same span.
May is one of the warmer months of the year in Olympia and one of the drier months, so plan for around 16.9°C daytime highs and 7.1°C at night.
Not quite — May is the 8th coolest month in Olympia, averaging 12°C.
For May in Olympia, pack warm layers and a jacket for chilly mornings, with typical highs of 16.9°C and lows of 7.1°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 83% — quite humid.
Average wind speed in May is 0.2 m/s. The windiest May on record averaged 0.2 m/s (1981).
The wettest May on record was 1984 with 158 mm. On average, May sees 82 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 Olympia 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.
