Weather in Spokane in September

Prime time. September is about as good as Spokane gets. Highs average 23.9 °C, lows 9.8 °C, and rain falls on 4 days — nothing in the month is working against you.

September is the highest-scoring month of the twelve. The nearest rival is June, and the month at the other end of the year is December.

Rain falls on only 4 days, so an itinerary with no wet-weather fallback is a reasonable risk. Nothing specialised needed — this is the month you pack for the trip rather than for the weather.

What the averages hide

Averages flatten a month, and this one hides a few things: 4 days top 30 °C — hot spells arrive, but they break. Across the twenty years measured, the hottest September day reached 36.5 °C and the coldest night fell to -0.8 °C.

September is moderately variable: 1 mm in the driest year against 69 mm in the wettest, around an average of 20 mm. Roughly two Septembers in three land near that average, and the third does something else entirely.

Wind is light at 6.6 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 54%.

How September sits in the year

The month is on the way down: 5.4 °C cooler than August, with October dropping another 8.6 °C. The first week and the last are not the same trip. Rain is the thing that moves: October brings 5 days more of it, so the earlier half of a flexible trip is the safer half.

Daylight in September

12.7 hours of daylight, losing 1.7 hours across the month. That is between Spokane's extremes of 16 and 8.5 hours, so days are long enough not to constrain the plan.

An inland climate

With no coast nearby, the year swings a fair way — 34.9 °C between the warmest afternoons and the coldest nights, wider than any coastal city at this latitude would manage. Within September itself the daily swing is 14.1 °C, so mornings and afternoons need different clothes.

How busy it gets

Peak season. Expect the highest prices of the year and to be booking well ahead.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

September in Spokane versus nearby

If Spokane is one option among several, the nearby comparison is worth making. Tri-Cities is close enough to be a coin toss — 3.5 °C warmer, 1 day less rain. Kelowna is close enough to be a coin toss — within a degree on temperature, 5 days more rain.

So: September is the answer for Spokane. If it is booked out or priced out, June is the next best thing at 8 points behind, and December is the month to keep off the shortlist.

Every month in Spokane

See all twelve months in Spokane, or where else to go in September.