Portland Weather in May
Average highs run from 65°F on May 1 to 70°F on May 31, and lows from 47°F to 51°F. Normal precipitation for the month is 2.58 in over about 12 wet days.
May day by day
The normal high and low for each date, and the record, in °F.
- Normal low
- Normal high
- Record high
- Record low
May at a glance
- Average high
- 68°F
- Average low
- 49°F
- Precipitation
- 2.58 in
- Record high
- 100°FMay 28, 1983
- Record low
- 29°FMay 1, 1954
- Chance of a freeze
- 0%
- Days of 90°F or more
- 0.5
- Daylight
- 14 h 20 min to 15 h 26 min
- Cloud cover
- 70%
- Humidity
- 82%
- Dew point
- 48°F
- Wind
- 4.5 mph
Every day of the month
A wet day has at least 0.01 inch of precipitation; snow means at least 0.1 inch of snowfall.
| Date | Normal high | Normal low | Record high | Record low | Chance wet | Chance of snow |
|---|---|---|---|---|---|---|
| May 1 | 65°F | 47°F | 89°F 2014 | 29°F 1954 | 47% | 0% |
| May 2 | 65°F | 47°F | 89°F 1945 | 32°F 1964 | 46% | 0% |
| May 3 | 65°F | 47°F | 91°F 2026 | 33°F 1964 | 46% | 0% |
| May 4 | 65°F | 47°F | 89°F 1992 | 34°F 1962 | 45% | 0% |
| May 5 | 66°F | 48°F | 87°F 1992 | 35°F 1978 | 44% | 0% |
| May 6 | 66°F | 48°F | 91°F 1987 | 36°F 1965 | 44% | 0% |
| May 7 | 66°F | 48°F | 93°F 1987 | 36°F 1965 | 43% | 0% |
| May 8 | 67°F | 48°F | 92°F 1987 | 35°F 1965 | 43% | 0% |
| May 9 | 67°F | 48°F | 91°F 1940 | 36°F 1955 | 42% | 0% |
| May 10 | 67°F | 49°F | 91°F 2024 | 37°F 1963 | 42% | 0% |
| May 11 | 67°F | 49°F | 91°F 1971 | 37°F 1953 | 42% | 0% |
| May 12 | 68°F | 49°F | 90°F 2023 | 37°F 1943 | 41% | 0% |
| May 13 | 68°F | 49°F | 96°F 1939 | 36°F 1956 | 41% | 0% |
| May 14 | 68°F | 49°F | 95°F 1939 | 33°F 1964 | 41% | 0% |
| May 15 | 68°F | 49°F | 93°F 2006 | 36°F 1964 | 40% | 0% |
| May 16 | 68°F | 50°F | 92°F 2008 | 40°F 1950 | 40% | 0% |
| May 17 | 69°F | 50°F | 95°F 2008 | 37°F 1966 | 40% | 0% |
| May 18 | 69°F | 50°F | 88°F 1940 | 38°F 2003 | 39% | 0% |
| May 19 | 69°F | 50°F | 91°F 1961 | 40°F 2003 | 39% | 0% |
| May 20 | 69°F | 50°F | 91°F 1963 | 37°F 1975 | 39% | 0% |
| May 21 | 69°F | 50°F | 87°F 1988 | 38°F 1955 | 39% | 0% |
| May 22 | 69°F | 50°F | 95°F 2001 | 33°F 1960 | 38% | 0% |
| May 23 | 70°F | 51°F | 90°F 1947 | 35°F 1964 | 38% | 0% |
| May 24 | 70°F | 51°F | 93°F 1992 | 37°F 1955 | 38% | 0% |
| May 25 | 70°F | 51°F | 90°F 1938 | 38°F 1964 | 37% | 0% |
| May 26 | 70°F | 51°F | 92°F 1947 | 41°F 1964 | 37% | 0% |
| May 27 | 70°F | 51°F | 95°F 2005 | 39°F 1966 | 37% | 0% |
| May 28 | 70°F | 51°F | 100°F 1983 | 38°F 1954 | 36% | 0% |
| May 29 | 70°F | 51°F | 90°F 1973 | 41°F 1978 | 36% | 0% |
| May 30 | 70°F | 51°F | 91°F 1986 | 40°F 1955 | 36% | 0% |
| May 31 | 70°F | 51°F | 93°F 2001 | 39°F 1966 | 36% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (PDT).
- May 1
- sunrise 5:58 AM, sunset 8:18 PM
- May 31
- sunrise 5:26 AM, sunset 8:52 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00356749 (Portland Kgw-TV), public domain. Records: NOAA GHCN-Daily, station USW00024229, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.