Weather in Tri-Cities in July

A hard month. July asks something of you. Go in knowing what. Daytime highs average 34.3 °C and the afternoon is not negotiable — outdoor plans move to early morning or evening.

July ranks 10 of 12 — near the bottom of Tri-Cities's year. September is the month that works, and the swing between the two is 53 points, which is a different holiday rather than a slightly better one.

Rain falls on only 1 days, so an itinerary with no wet-weather fallback is a reasonable risk. Pack for heat management rather than style: shade, water, and a schedule that gives up on the middle of the day.

What the averages hide

Averages flatten a month, and this one hides a few things: 14 days clear 35 °C, so a serious heatwave is normal rather than notable; the day swings 16.1 °C from low to high, which means one bag has to cover both. Across the twenty years measured, the hottest July day reached 44.4 °C and the coldest night fell to 11.1 °C.

July is dependably dry, and that reliability is the point: across the twenty years measured, the wettest July on record still only managed 13 mm, and the driest managed 0 mm. There is no meaningful variability to plan around, which makes this one of the few months anywhere that you can build a fixed outdoor itinerary against without a fallback. The wettest single day in twenty years of Julys brought 6 mm. Rain simply is not the variable that decides this trip — heat, crowds and cost are.

Wind is light at 9.5 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 41%.

How July sits in the year

This is a turning point in the year — June and August sit on opposite sides of it, so the month contains the change rather than following it.

Daylight in July

July is at or near the longest days of Tri-Cities's year: 15.5 hours of daylight, losing 0.8 hours across the month. Evenings are the real gain — dinner outdoors still happens in full light.

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. Within July itself the daily swing is 16.1 °C, so mornings and afternoons need different clothes.

How busy it gets

Quiet. Few other visitors, cheaper rooms, and a real chance some seasonal operators are shut.

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

July in Tri-Cities versus nearby

If Tri-Cities is one option among several, the nearby comparison is worth making. Spokane is a better bet in July — 4.4 °C cooler, 2 days more rain. Portland is a better bet in July — 6 °C cooler, 2 days more rain.

So: July is a compromise. September is 45 points better and is what Tri-Cities is actually like at its best — worth moving the trip for if that is possible, and worth adjusting expectations for if it is not.

Every month in Tri-Cities

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