Hermiston climate

Hermiston Weather in May

NOAA 1991-2020 normals for Hermiston Muni AP, 2.7 km from Hermiston

Average highs run from 72°F on May 1 to 79°F on May 31, and lows from 42°F to 50°F. Normal precipitation for the month is 0.83 in over about 8 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 Hermiston, in °F, with the record for each date.20406080100120151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

May at a glance

Average high
76°F
Average low
46°F
Precipitation
0.83 in
Record high
100°FMay 18, 2006
Record low
24°FMay 1, 2013
Chance of a freeze
34%
Days of 90°F or more
2.3
Daylight
14 h 21 min to 15 h 28 min
Cloud cover
58%
Humidity
53%
Dew point
42°F
Wind
8.7 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 172°F42°F86°F 199824°F 201323%0%
May 273°F42°F88°F 201625°F 200623%0%
May 373°F42°F92°F 201625°F 200623%0%
May 473°F43°F89°F 201729°F 201123%0%
May 574°F43°F85°F 202633°F 200623%0%
May 674°F43°F89°F 201327°F 200023%0%
May 774°F44°F89°F 201330°F 200323%0%
May 875°F44°F91°F 200728°F 200223%0%
May 975°F44°F92°F 201329°F 200623%0%
May 1075°F45°F96°F 201325°F 199923%0%
May 1176°F45°F94°F 201329°F 199924%0%
May 1276°F45°F89°F 200131°F 201224%0%
May 1376°F46°F92°F 202329°F 200624%0%
May 1476°F46°F92°F 202334°F 199924%0%
May 1577°F46°F94°F 201834°F 200924%0%
May 1677°F46°F97°F 200632°F 200224%0%
May 1777°F47°F99°F 200635°F 200124%0%
May 1877°F47°F100°F 200637°F 200324%0%
May 1977°F47°F96°F 202330°F 200324%0%
May 2077°F48°F97°F 202335°F 200324%0%
May 2178°F48°F90°F 200035°F 200124%0%
May 2278°F48°F95°F 200136°F 200924%0%
May 2378°F49°F99°F 200134°F 201324%0%
May 2478°F49°F95°F 200135°F 200224%0%
May 2578°F49°F90°F 200139°F 201024%0%
May 2678°F49°F94°F 200134°F 199924%0%
May 2778°F50°F94°F 200537°F 199923%0%
May 2878°F50°F97°F 200538°F 199823%0%
May 2979°F50°F97°F 201737°F 200123%0%
May 3079°F50°F96°F 200937°F 201423%0%
May 3179°F50°F93°F 200139°F 201622%0%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Hermiston, in percent, and of at least 0.1 inch of snowfall.05101520251102030
  • Chance of a wet day
  • Chance of snowfall

Sunrise and sunset

Times for 2026, local time (PDT).

May 1
sunrise 5:44 AM, sunset 8:05 PM
May 31
sunrise 5:11 AM, sunset 8:39 PM

Every day of May: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USW00004113 (Hermiston Muni AP), public domain. Records: NOAA GHCN-Daily, station USW00004113, 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.