Weather in Tri-Cities in October

Prime time. October is about as good as Tri-Cities gets. Highs average 19.3 °C, lows 8.1 °C, and rain falls on 6 days — nothing in the month is working against you.

October ranks 3 of 12 in Tri-Cities. Only September scores clearly higher, and the difference is small enough to be settled by price rather than weather.

Rain falls on only 6 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: it never really gets hot: not one day in an average October reaches 30 °C. Across the twenty years measured, the hottest October day reached 31.8 °C and the coldest night fell to -5.3 °C.

October is moderately variable: 6 mm in the driest year against 70 mm in the wettest, around an average of 24 mm. Roughly two Octobers in three land near that average, and the third does something else entirely.

Wind is light at 8.7 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 60%.

How October sits in the year

The month is on the way down: 8.1 °C cooler than September, with November dropping another 7.5 °C. The first week and the last are not the same trip.

Daylight in October

11 hours of daylight, losing 1.6 hours across the month. That is between Tri-Cities's extremes of 15.8 and 8.6 hours, so days are long enough not to constrain the plan.

An inland climate

With no coast nearby, the year swings a fair way — 34.6 °C between the warmest afternoons and the coldest nights, wider than any coastal city at this latitude would manage.

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.

October in Tri-Cities versus nearby

If Tri-Cities is one option among several, the nearby comparison is worth making. Spokane is the weaker option in October — 4 °C cooler, 3 days more rain. Portland is the weaker option in October — within a degree on temperature, 8 days more rain.

So: October is effectively as good as it gets here — 5 points behind September, which is inside the margin where the weather stops being the deciding factor and price starts being it.

Every month in Tri-Cities

See all twelve months in Tri-Cities, or where else to go in October.