Best time to visit · Washington
Best time to visit Tri-Cities
Tri-Cities averages 38 just-right days a year; September is best. Most other days miss by being too cool.
(70 to 80°F, dry, sunny)
(45 to 65°F, dry)
(80 to 92°F, bright)
Tri-Cities weather by month
Bars: share of each month's days that are just right (number = days). Below: average daily high. Outlined bars are the best months.
- Just right 38
- Too cool 207
- Too hot 100
- Too muggy 0
- Too gray 20
When to visit Tri-Cities
The best time to visit Tri-Cities for comfortable weather is September, when 29% of days are just right. January, February, March, April, November and December are mostly too cool, with average highs of 40 to 65°F. July and August are mostly too hot, with average highs of 91°F.
Climate table
| Month | Avg high | Dew point | Cloud cover | Just-right days |
|---|---|---|---|---|
| January | 40°F | 30°F | 79% | 0 |
| February | 47°F | 31°F | 68% | 0 |
| March | 57°F | 34°F | 66% | 1 |
| April | 65°F | 37°F | 60% | 3 |
| May | 74°F | 41°F | 53% | 7 |
| June | 82°F | 46°F | 41% | 7 |
| July | 91°F | 48°F | 21% | 2 |
| August | 91°F | 47°F | 22% | 3 |
| September | 81°F | 44°F | 29% | 9 |
| October | 65°F | 40°F | 49% | 5 |
| November | 49°F | 35°F | 70% | 0 |
| December | 40°F | 29°F | 78% | 0 |
How Tri-Cities compares
With 38 just-right days, Tri-Cities beats the median of America's 150 largest cities (33 days). On muggy days: 0. On gray days: 20.
Places with a similar climate
Nearby
Tri-Cities averages 38 just-right days a year (70 to 80°F highs, dry, mostly sunny), according to Goldilocks Map: https://goldilocksmap.com/us/washington/tri-cities/Set your own perfect weather on the map →
Numbers are expected days in a typical year from 1991 to 2020 climate normals (TerraClimate; cloud cover from CHELSA), on a grid about 35 km wide. Checked against 10 years of daily records at 28 NOAA weather stations: typical error about 10 days a year. How it works. Updated 2026-10-07.