Tri-Cities climate

Tri-Cities Weather in May

NOAA 1991-2020 normals for Pasco Tri Cities AP, 6.6 km from Tri-Cities

Average highs run from 73°F on May 1 to 79°F on May 31, and lows from 41°F to 51°F. Normal precipitation for the month is 0.71 in over about 7 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 Tri-Cities, in °F, with the record for each date.20406080100120151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

May at a glance

Average high
77°F
Average low
46°F
Precipitation
0.71 in
Record high
101°FMay 23, 2001
Record low
28°FMay 5, 1999
Chance of a freeze
35%
Days of 90°F or more
3.0
Daylight
14 h 23 min to 15 h 31 min
Cloud cover
58%
Humidity
58%
Dew point
43°F
Wind
8.1 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 173°F41°F91°F 199828°F 201321%0%
May 273°F42°F90°F 201429°F 200822%0%
May 373°F42°F91°F 194631°F 200622%0%
May 474°F42°F92°F 201730°F 201122%0%
May 574°F43°F88°F 194528°F 199922%0%
May 674°F43°F89°F 201330°F 200022%0%
May 775°F43°F91°F 201330°F 200322%0%
May 875°F44°F93°F 200729°F 200222%0%
May 975°F44°F93°F 201329°F 199922%0%
May 1075°F44°F97°F 201330°F 199922%0%
May 1176°F45°F96°F 201330°F 199922%0%
May 1276°F45°F92°F 200132°F 201222%0%
May 1376°F45°F93°F 202332°F 200622%0%
May 1476°F46°F94°F 202338°F 200622%0%
May 1577°F46°F94°F 201233°F 201723%0%
May 1677°F47°F96°F 200634°F 199823%0%
May 1777°F47°F100°F 200633°F 201123%0%
May 1877°F47°F99°F 200636°F 200123%0%
May 1978°F48°F98°F 202332°F 200323%0%
May 2078°F48°F98°F 202340°F 199923%0%
May 2178°F48°F91°F 200033°F 200923%0%
May 2278°F48°F96°F 200136°F 200923%0%
May 2378°F49°F101°F 200136°F 201322%0%
May 2478°F49°F96°F 200139°F 200222%0%
May 2579°F49°F92°F 200141°F 200522%0%
May 2679°F50°F96°F 200135°F 199922%0%
May 2779°F50°F94°F 200538°F 199922%0%
May 2879°F50°F96°F 200537°F 199822%0%
May 2979°F50°F96°F 200937°F 200121%0%
May 3079°F51°F98°F 200939°F 200121%0%
May 3179°F51°F95°F 202541°F 202421%0%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Tri-Cities, 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 5:43 AM, sunset 8:06 PM
May 31
sunrise 5:09 AM, sunset 8:40 PM

Every day of May: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USW00024163 (Pasco Tri Cities AP), public domain. Records: NOAA GHCN-Daily, station USW00024163, 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.