Saint Helens climate

Saint Helens Weather in May

NOAA 1991-2020 normals for Scappoose Ind AP, 11 km from Saint Helens

Average highs run from 65°F on May 1 to 70°F on May 31, and lows from 43°F to 49°F. Normal precipitation for the month is 2.49 in over about 13 wet days.

May day by day

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

Normal daily high and low temperature at Saint Helens, 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
46°F
Precipitation
2.49 in
Record high
96°FMay 16, 2008
Record low
31°FMay 10, 2012
Chance of a freeze
11%
Days of 90°F or more
0.5
Daylight
14 h 21 min to 15 h 28 min
Cloud cover
71%
Humidity
84%
Dew point
47°F
Wind
3.8 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 165°F43°F87°F 201432°F 201148%0%
May 265°F43°F86°F 201633°F 200647%0%
May 366°F43°F89°F 202636°F 200247%0%
May 466°F44°F84°F 201334°F 200246%0%
May 566°F44°F85°F 201334°F 199946%0%
May 666°F44°F84°F 201332°F 201045%0%
May 767°F44°F85°F 201632°F 200245%0%
May 867°F45°F80°F 201532°F 200244%0%
May 967°F45°F87°F 201932°F 200644%0%
May 1067°F45°F91°F 202431°F 201243%0%
May 1168°F45°F87°F 202434°F 201143%0%
May 1268°F46°F89°F 202334°F 201143%0%
May 1368°F46°F93°F 202335°F 202243%0%
May 1468°F46°F91°F 201441°F 201343%0%
May 1568°F46°F94°F 200637°F 200942%0%
May 1669°F46°F96°F 200837°F 200242%0%
May 1769°F47°F92°F 200835°F 200342%0%
May 1869°F47°F83°F 200634°F 200342%0%
May 1969°F47°F83°F 202336°F 200342%0%
May 2069°F47°F81°F 202336°F 202142%0%
May 2169°F47°F83°F 200139°F 200742%0%
May 2269°F48°F93°F 200139°F 201041%0%
May 2370°F48°F88°F 199937°F 200541%0%
May 2470°F48°F79°F 199936°F 201141%0%
May 2570°F48°F82°F 200537°F 201140%0%
May 2670°F48°F89°F 200533°F 201140%0%
May 2770°F48°F94°F 200539°F 201140%0%
May 2870°F49°F92°F 202039°F 200140%0%
May 2970°F49°F87°F 200736°F 200139%0%
May 3070°F49°F90°F 200737°F 199939%0%
May 3170°F49°F90°F 200139°F 202639%0%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Saint Helens, in percent, and of at least 0.1 inch of snowfall.010203040501102030
  • Chance of a wet day
  • Chance of snowfall

Sunrise and sunset

Times for 2026, local time (PDT).

May 1
sunrise 5:58 AM, sunset 8:19 PM
May 31
sunrise 5:25 AM, sunset 8:53 PM

Every day of May: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USW00004201 (Scappoose Ind AP), public domain. Records: NOAA GHCN-Daily, station USW00004201, 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.