May is one of the warmer months of the year in Astoria, with average highs near 20°C and lows around 9.5°C (mean 14.8°C). It is about average for rainfall, averaging 108 mm of rainfall and 80% relative humidity across the period.
May is one of the warmer months of the year in Astoria. Across 45 years of records, the warmest Mays in Astoria were 1991 and 2012 — when the month averaged 17.1°C — while the coldest was 1997 at 12.4°C. Typical May days reach 20°C with nights near 9.5°C. The long-term trend is warming, about 0.3°C per decade.
May is about average for rainfall in Astoria, averaging 108 mm of rainfall. The wettest May on record was 1989 with 271 mm, while the driest was 2015 at 34 mm.
Relative humidity in Astoria during May averages 80%. The most humid May was 2011 at 85%, and the least humid were 2002 and 2023 at 74%.
May receives about 5.6 kWh/m²/day of solar energy in Astoria. The sunniest Mays were 1986, 2007 and 2023 at 6.7 kWh/m²/day, and the cloudiest was 1984 at 4.2.
Average wind speed in Astoria during May is 1.4 m/s. The windiest May was 1997 at 1.7 m/s, while the calmest were 1982, 2012 and 2018 at 1.2 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 14.4°C | 14.2°C | 14.5°C | 15.6°C | 15.0°C | +0.6°C |
| Avg High | 19.7°C | 19.6°C | 19.8°C | 20.6°C | 20.2°C | +0.5°C |
| Avg Low | 9.1°C | 8.8°C | 9.3°C | 10.7°C | 9.9°C | +0.8°C |
| Avg Rain | 134 mm | 101 mm | 92 mm | 108 mm | 103 mm | -31 mm |
May temperatures in Astoria have risen by about 1.1°C between 1981–1985 and 2021–2025.
May has ranged from a record low of 0.1°C (1986) to a record high of 31.3°C (2022).
Rainfall in May is about average for rainfall, averaging 108 mm, with a wettest year of 271 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.2°C per decade while lows rose 0.4°C per decade, narrowing the gap between day and night.
A good time to visit Astoria
May is a good time to visit Astoria, with days averaging 20°C and nights around 9.5°C (mean 14.8°C, warmer than Astoria'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 | 19.9°C | 15.3°C | 10.6°C | 25.5°C | 6.5°C | 177 mm | 82% | 1.5 m/s | 4.9 |
| 2024 | 21.4°C | 16.6°C | 11.8°C | 27.3°C | 6.3°C | 106 mm | 83% | 1.3 m/s | 5.5 |
| 2023 | 20.2°C | 14.5°C | 8.8°C | 27.2°C | 2.4°C | 44 mm | 74% | 1.3 m/s | 6.7 |
| 2022 | 21.1°C | 15.8°C | 10.4°C | 31.3°C | 3.3°C | 104 mm | 80% | 1.4 m/s | 5.5 |
| 2021 | 20.0°C | 14.8°C | 9.6°C | 28.6°C | 3.0°C | 130 mm | 77% | 1.4 m/s | 6 |
| 2020 | 18.5°C | 13.2°C | 7.9°C | 24.9°C | 0.8°C | 58 mm | 77% | 1.5 m/s | 6.1 |
| 2019 | 19.6°C | 15.0°C | 10.4°C | 27.6°C | 4.9°C | 168 mm | 83% | 1.5 m/s | 5.3 |
| 2018 | 21.8°C | 16.8°C | 11.9°C | 29.5°C | 2.7°C | 101 mm | 83% | 1.2 m/s | 5.1 |
| 2017 | 18.6°C | 14.1°C | 9.5°C | 29.3°C | 3.9°C | 153 mm | 81% | 1.5 m/s | 5.4 |
| 2016 | 19.5°C | 14.7°C | 9.9°C | 28.5°C | 2.9°C | 101 mm | 80% | 1.3 m/s | 5 |
| 2015 | 22.7°C | 17.0°C | 11.3°C | 27.4°C | 5.1°C | 34 mm | 77% | 1.3 m/s | 6.3 |
| 2014 | 20.3°C | 15.2°C | 10.2°C | 26.6°C | 4.6°C | 90 mm | 81% | 1.3 m/s | 5.6 |
| 2013 | 20.0°C | 14.7°C | 9.5°C | 29.6°C | 1.8°C | 120 mm | 81% | 1.4 m/s | 5.7 |
| 2012 | 21.7°C | 17.1°C | 12.5°C | 30.2°C | 6.0°C | 122 mm | 83% | 1.2 m/s | 5.2 |
| 2011 | 20.7°C | 15.9°C | 11.2°C | 28.6°C | 4.3°C | 122 mm | 85% | 1.4 m/s | 5.4 |
| 2010 | 21.4°C | 15.9°C | 10.4°C | 30.2°C | 1.5°C | 71 mm | 80% | 1.4 m/s | 6.1 |
| 2009 | 20.2°C | 15.2°C | 10.2°C | 25.5°C | 3.8°C | 110 mm | 80% | 1.4 m/s | 5.1 |
| 2008 | 18.5°C | 13.3°C | 8.0°C | 26.1°C | 1.9°C | 96 mm | 79% | 1.6 m/s | 5.7 |
| 2007 | 21.5°C | 15.6°C | 9.7°C | 29.3°C | 3.0°C | 38 mm | 77% | 1.3 m/s | 6.7 |
| 2006 | 20.1°C | 14.9°C | 9.7°C | 29.3°C | 4.0°C | 105 mm | 79% | 1.4 m/s | 5.7 |
| 2005 | 17.7°C | 12.6°C | 7.6°C | 23.9°C | 2.7°C | 44 mm | 79% | 1.4 m/s | 5.9 |
| 2004 | 21.8°C | 16.4°C | 11.1°C | 28.0°C | 3.4°C | 107 mm | 83% | 1.3 m/s | 5.5 |
| 2003 | 17.8°C | 13.1°C | 8.4°C | 23.8°C | 4.1°C | 116 mm | 83% | 1.3 m/s | 4.4 |
| 2002 | 19.4°C | 13.7°C | 8.0°C | 26.5°C | 1.5°C | 123 mm | 74% | 1.6 m/s | 6.3 |
| 2001 | 20.8°C | 15.3°C | 9.9°C | 30.1°C | 3.7°C | 78 mm | 75% | 1.4 m/s | 5.8 |
| 2000 | 20.2°C | 15.0°C | 9.9°C | 29.5°C | 2.4°C | 104 mm | 80% | 1.4 m/s | 5.4 |
| 1999 | 20.9°C | 15.2°C | 9.4°C | 29.6°C | 3.7°C | 86 mm | 75% | 1.3 m/s | 5.8 |
| 1998 | 21.0°C | 15.8°C | 10.7°C | 27.5°C | 3.2°C | 178 mm | 83% | 1.4 m/s | 5.3 |
| 1997 ❄️ | 17.8°C | 12.4°C | 7.0°C | 25.8°C | 1.3°C | 81 mm | 77% | 1.7 m/s | 6.1 |
| 1996 | 18.3°C | 13.0°C | 7.8°C | 28.7°C | 0.1°C | 75 mm | 80% | 1.4 m/s | 5.5 |
| 1995 | 19.0°C | 13.7°C | 8.5°C | 26.1°C | 2.3°C | 65 mm | 76% | 1.4 m/s | 5.4 |
| 1994 | 19.0°C | 13.4°C | 7.8°C | 28.2°C | 2.7°C | 94 mm | 79% | 1.5 m/s | 6 |
| 1993 | 20.6°C | 15.1°C | 9.6°C | 27.0°C | 6.2°C | 41 mm | 78% | 1.3 m/s | 6.1 |
| 1992 | 19.2°C | 13.4°C | 7.7°C | 29.0°C | 1.1°C | 103 mm | 76% | 1.3 m/s | 5.4 |
| 1991 🔥 | 22.6°C | 17.1°C | 11.6°C | 28.3°C | 4.9°C | 84 mm | 80% | 1.3 m/s | 6.3 |
| 1990 | 17.9°C | 12.9°C | 7.9°C | 22.7°C | 2.8°C | 204 mm | 80% | 1.6 m/s | 5.4 |
| 1989 🌧️ | 19.2°C | 14.2°C | 9.1°C | 25.5°C | 3.5°C | 271 mm | 84% | 1.5 m/s | 5.1 |
| 1988 | 19.8°C | 14.7°C | 9.6°C | 27.6°C | 3.4°C | 131 mm | 83% | 1.3 m/s | 5 |
| 1987 | 19.5°C | 14.1°C | 8.8°C | 29.2°C | 2.7°C | 52 mm | 83% | 1.3 m/s | 5.7 |
| 1986 | 20.8°C | 15.3°C | 9.9°C | 28.4°C | 0.1°C | 43 mm | 79% | 1.4 m/s | 6.7 |
| 1985 | 21.2°C | 15.5°C | 9.9°C | 27.2°C | 1.0°C | 144 mm | 74% | 1.5 m/s | 6.3 |
| 1984 | 17.9°C | 13.1°C | 8.2°C | 24.9°C | 2.3°C | 250 mm | 83% | 1.5 m/s | 4.2 |
| 1983 | 18.0°C | 12.9°C | 7.9°C | 24.2°C | 1.1°C | 128 mm | 84% | 1.5 m/s | — |
| 1982 | 20.7°C | 15.2°C | 9.8°C | 25.2°C | 5.5°C | 77 mm | 79% | 1.2 m/s | — |
| 1981 | 20.6°C | 14.6°C | 8.6°C | 27.1°C | 1.9°C | 107 mm | 75% | 1.4 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 20°C with lows near 9.5°C (mean 14.8°C), based on 45 years of NASA POWER data.
May averages 108 mm of rainfall in Astoria, about average for rainfall. The wettest on record was 271 mm in 1989.
The hottest May reached 31.3°C in 2022. The coldest dipped to 0.1°C in 1986.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 1.1°C. Daytime highs moved from 19.7°C to 20.5°C and overnight lows from 8.9°C to 10.2°C over the same span.
May is one of the warmer months of the year in Astoria and about average for rainfall, so plan for around 20°C daytime highs and 9.5°C at night.
Not quite — May is the 8th coolest month in Astoria, averaging 14.8°C.
For May in Astoria, pack light layers you can adjust through the day, with typical highs of 20°C and lows of 9.5°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 80% — quite humid.
Average wind speed in May is 1.4 m/s. The windiest May on record averaged 1.7 m/s (1997).
The wettest May on record was 1989 with 271 mm. On average, May sees 108 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 Astoria 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.
