Mattawa climate

Mattawa Weather in May

NOAA 1991-2020 normals for Priest Rapids Dam, 10.2 km from Mattawa

Average highs run from 71°F on May 1 to 79°F on May 31, and lows from 49°F to 56°F. Normal precipitation for the month is 0.55 in over about 5 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 Mattawa, in °F, with the record for each date.020406080100151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

May at a glance

Average high
75°F
Average low
53°F
Precipitation
0.55 in
Record high
99°FMay 17, 2006
Record low
20°FMay 8, 2020
Chance of a freeze
0%
Days of 90°F or more
2.3
Daylight
14 h 26 min to 15 h 35 min
Cloud cover
58%
Humidity
52%
Dew point
40°F
Wind
7.8 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 171°F49°F84°F 202325°F 201315%0%
May 271°F49°F82°F 200428°F 200115%0%
May 371°F49°F84°F 202628°F 200715%0%
May 472°F49°F87°F 202323°F 202015%0%
May 572°F50°F88°F 202625°F 201515%0%
May 673°F50°F86°F 202627°F 200015%0%
May 773°F50°F86°F 201326°F 200215%0%
May 873°F51°F87°F 201320°F 202015%0%
May 974°F51°F90°F 201329°F 199915%0%
May 1074°F51°F91°F 201325°F 199915%0%
May 1174°F51°F92°F 201328°F 199916%0%
May 1275°F52°F89°F 201331°F 200016%0%
May 1375°F52°F88°F 200129°F 202216%0%
May 1475°F52°F89°F 202429°F 199916%0%
May 1575°F53°F91°F 201231°F 201716%0%
May 1676°F53°F94°F 200626°F 200317%0%
May 1776°F53°F99°F 200624°F 200317%0%
May 1876°F53°F98°F 200627°F 200317%0%
May 1976°F54°F99°F 200627°F 200317%0%
May 2077°F54°F91°F 202332°F 200917%0%
May 2177°F54°F93°F 202334°F 200517%0%
May 2277°F54°F84°F 200133°F 201017%0%
May 2377°F55°F94°F 200133°F 201017%0%
May 2477°F55°F99°F 200135°F 201217%0%
May 2578°F55°F94°F 199937°F 202417%0%
May 2678°F55°F91°F 200134°F 199917%0%
May 2778°F56°F93°F 200136°F 199917%0%
May 2878°F56°F91°F 200533°F 201117%0%
May 2978°F56°F96°F 200530°F 200117%0%
May 3078°F56°F94°F 200536°F 200617%0%
May 3179°F56°F95°F 200537°F 202417%0%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Mattawa, in percent, and of at least 0.1 inch of snowfall.051015201102030
  • Chance of a wet day
  • Chance of snowfall

Sunrise and sunset

Times for 2026, local time (PDT).

May 1
sunrise 5:44 AM, sunset 8:10 PM
May 31
sunrise 5:10 AM, sunset 8:45 PM

Every day of May: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00456747 (Priest Rapids Dam), public domain. Records: NOAA GHCN-Daily, station USC00457522, 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.