Portland climate

Portland Weather in May

NOAA 1991-2020 normals for Portland1 Sw, 1.8 km from Portland

Average highs run from 63°F on May 1 to 73°F on May 31, and lows from 43°F to 54°F. Normal precipitation for the month is 3.69 in.

May day by day

The normal high and low for each date, and the record, in °F.

Normal daily high and low temperature at Portland, in °F, with the record for each date.20406080100151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

May at a glance

Average high
68°F
Average low
49°F
Precipitation
3.69 in
Record high
89°FMay 30, 2018
Record low
27°FMay 5, 2005
Chance of a freeze
35%
Daylight
14 h 05 min to 15 h 04 min
Cloud cover
76%
Humidity
79%
Dew point
47°F
Wind
7.2 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.

DateNormal highNormal lowRecord highRecord lowChance wetChance of snow
May 163°F43°F83°F 201929°F 2002
May 263°F43°F82°F 201034°F 1952
May 364°F44°F82°F 201232°F 1946
May 464°F44°F83°F 201830°F 2002
May 564°F44°F85°F 195027°F 2005
May 665°F45°F83°F 199935°F 1951
May 765°F45°F79°F 200029°F 2006
May 865°F45°F86°F 201531°F 20200%
May 966°F46°F86°F 201528°F 20170%
May 1066°F46°F82°F 200430°F 20100%
May 1167°F47°F84°F 195331°F 19490%
May 1267°F47°F82°F 202229°F 20200%
May 1367°F47°F84°F 201427°F 20200%
May 1468°F48°F82°F 200433°F 20070%
May 1568°F48°F82°F 199837°F 20230%
May 1668°F49°F88°F 199837°F 20000%
May 1769°F49°F86°F 199935°F 20050%
May 1869°F49°F86°F 199929°F 20090%
May 1969°F50°F88°F 201929°F 20090%
May 2070°F50°F87°F 202432°F 20020%
May 2170°F51°F87°F 201330°F 20020%
May 2270°F51°F88°F 201334°F 20030%
May 2371°F51°F82°F 200730°F 20150%
May 2471°F52°F85°F 200740°F 19510%
May 2571°F52°F88°F 201235°F 20020%
May 2672°F53°F88°F 202036°F 19970%
May 2772°F53°F84°F 202034°F 20130%
May 2872°F53°F88°F 201233°F 20080%
May 2973°F54°F86°F 200638°F 20040%
May 3073°F54°F89°F 201838°F 19490%
May 3173°F54°F88°F 200637°F 20010%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Portland, in percent, and of at least 0.1 inch of snowfall.00.21102030
  • Chance of a wet day
  • Chance of snowfall

Sunrise and sunset

Times for 2026, local time (EDT).

May 1
sunrise 6:13 AM, sunset 8:18 PM
May 31
sunrise 5:44 AM, sunset 8:48 PM

Every day of May: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00306747 (Portland1 Sw), public domain. Records: NOAA GHCN-Daily, station USW00014747, 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.