Weather in Boise in October

Prime time. If you get to pick your dates, October is the one. Highs average 18.8 °C, lows 6.6 °C, and rain falls on 5 days — nothing in the month is working against you.

October ranks 2 of 12 in Boise. Only September scores clearly higher, and the difference is small enough to be settled by price rather than weather.

Rain falls on only 5 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

The averages here are honest — no hidden extremes worth planning around. Across the twenty years measured, the hottest October day reached 35 °C and the coldest night fell to -6.2 °C.

October is moderately variable: 2 mm in the driest year against 55 mm in the wettest, around an average of 27 mm. Roughly two Octobers in three land near that average, and the third does something else entirely.

Wind is light at 7.3 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 49%.

How October sits in the year

The month is on the way down: 9.1 °C cooler than September, with November dropping another 8.3 °C. The first week and the last are not the same trip.

Daylight in October

11.1 hours of daylight, losing 1.4 hours across the month. That is between Boise's extremes of 15.4 and 9 hours, so days are long enough not to constrain the plan.

An inland climate

With no coast nearby, the year swings a fair way — 38.7 °C between the warmest afternoons and the coldest nights, wider than any coastal city at this latitude would manage. At 823 m the air is thin enough to matter — sun that burns faster than the temperature suggests, and nights that cool off quickly.

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 Boise versus nearby

If Boise is one option among several, the nearby comparison is worth making. Tri-Cities is close enough to be a coin toss — within a degree on temperature, 1 day more rain. Spokane is the weaker option in October — 3.5 °C cooler, 4 days more rain.

So: October is effectively as good as it gets here — 3 points behind September, which is inside the margin where the weather stops being the deciding factor and price starts being it.

Every month in Boise

See all twelve months in Boise, or where else to go in October.