Climate in Tri-Cities: average temperature by month
In Tri-Cities the warmest month is July, with 30.8 °C on average in the afternoon; the coolest is January, with 2.3 °C.
The average of the weather stations Spokane Intl Ap (199 km) and Payette (299 km); nearer ones count more.
| Month | Average high | Coolest to warmest day |
|---|---|---|
| January | 2.3 °C | 1.4 °C – 3.7 °C |
| February | 5.3 °C | 3.8 °C – 7.1 °C |
| March | 10.9 °C | 7.5 °C – 13.0 °C |
| April | 15.8 °C | 13.3 °C – 18.5 °C |
| May | 21.1 °C | 18.7 °C – 23.5 °C |
| June | 25.2 °C | 23.7 °C – 28.3 °C |
| July | 30.8 °C | 28.5 °C – 32.1 °C |
| August | 30.1 °C | 27.8 °C – 31.9 °C |
| September | 24.2 °C | 21.2 °C – 27.7 °C |
| October | 16.3 °C | 11.5 °C – 21.0 °C |
| November | 7.6 °C | 4.2 °C – 11.2 °C |
| December | 2.3 °C | 1.3 °C – 4.0 °C |