Weather in Boise in April

A good month. April works. It is not the peak, but nothing about it fights you. Highs average 16.5 °C, lows 3.9 °C, and rain falls on 9 days — nothing in the month is working against you.

April ranks 5 of 12 in Boise: past the worst of the year but short of September, which is the month to book if the dates are open.

Rain on 9 days, 0 of them heavy. Enough to need a plan B, not enough to need a plan around it. Pack for 16.5 °C days and 3.9 °C nights; the spread matters more here than any single number.

What the averages hide

Averages flatten a month, and this one hides a few things: 5 nights fall below freezing. Across the twenty years measured, the hottest April day reached 31.8 °C and the coldest night fell to -3.4 °C.

April is statistically steady but not small: the year-to-year variation is modest in relative terms, yet the wettest April on record still delivered 59 mm against 12 mm in the driest. In a month this wet, even a tame spread is a lot of rain in absolute terms — the 35 mm average is a reasonable planning figure, not a promise.

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 58%.

How April sits in the year

The month is on the way up: 4 °C warmer than March, and May adds another 6 °C. Late in the month feels noticeably different from the start of it, which is worth knowing if the trip is short.

Daylight in April

13.4 hours of daylight, gaining 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

Busy. Popular without being frantic; book the things you care about, improvise the rest.

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

April in Boise versus nearby

If Boise is one option among several, the nearby comparison is worth making. Tri-Cities is a better bet in April — 2.4 °C warmer, 2 days less rain. Spokane is the weaker option in April — 2.3 °C cooler, 1 day more rain.

So: April works, with September the better month by 17 points if the dates can move. If they cannot, nothing here should stop you booking.

Every month in Boise

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