‘Unusually wet’ weather forecast for Boise area. How much rain will we get?
Rain, lightning and strong wind gusts should sweep through the Boise area Tuesday as monsoonal winds lock loads of moisture into the atmosphere, forecasters say.
“It’s a pretty unusually wet system,” Jackson Macfarlane, a meteorologist with the National Weather Service office in Boise, told the Idaho Statesman via phone.
According to Macfarlane, thunderstorms are expected to develop farther west across the Owyhee range later in the afternoon of Tuesday, July 14.
The forecaster said a “band of precipitation or rain” is moving through the lower Treasure Valley, from Ontario to Caldwell.
“We’re just going to continue to see these steady rain showers … due to that high atmospheric moisture,” Macfarlane said.
How much rain will Boise get?
According to the National Weather Service’s current forecast for Boise, winds of 8 to 10 mph were expected in the Treasure Valley on Tuesday.
Macfarlane warned that gusts will reach 40 mph Tuesday afternoon.
“There’s the chance for some stray showers moving into the Treasure Valley here with the winds and the lightning,” Macfarlane said.
Close to a half-inch of rain may fall in some locations throughout the day due to “spotty” showers, according to the forecaster.
The storm system is spread wide with some core thunderstorm developments, Macfarlane explained. Since air moisture levels are high everywhere, precipitation can gather and fall sporadically across the region.
How does moisture in the air impact weather patterns?
Precipitable water measures how much total water is in the air that may fall at any given moment.
As of Tuesday, Boise’s precipitable water level was at 1.2 inches, which is approximately double the amount of moisture that is typical for the area, according to Korri Anderson, a Boise-based meteorologist with the National Weather Service.
Anderson added that increased precipitable water can increase humidity and the likelihood for quickly developing heavy downpours.
Is Claremont Fire burn scar at risk of flash flooding?
According to Anderson, rain in areas scorched by wildfires can lead to debris runoff and flooding hazards.
The Claremont Fire burn scar could see a half-inch of rain, according to Macfarlane.
“Half an inch of rainfall in an hour on pretty much any of our burn scars is enough to bring at least a minor risk of flash flooding and debris flows,” the meteorologist said.
“We’re really highlighting the burn scars with this system as well as steep terrain, just because those are the most receptive areas,” Macfarlane said. “A shower over it is going to warrant our attention.”
What’s the weather forecast for Boise?
Tuesday “is going to be the coldest day in the forecast,” Macfarlane said, even though the high temperature is forecast to reach 92 degrees.
“We are going to climb pretty quickly after the (storm) system,” he said.
Boise is forecast to be sunny and hot on Wednesday, July 13, with a high near 98 and a low around 66.
Thursday, July 16, will have a high near 103, while the overnight low will drop to 67.
“(From) Thursday onwards, we are just consistently forecasting around that 100-degree mark,” Macfarlane said.
Highs will hover around 100 degrees heading into the weekend, while lows will be in the mid-60s.
After strong wind gusts on Tuesday, milder winds up to 8 mph will breeze through Boise until Wednesday night.
This story was originally published July 14, 2026 at 11:51 AM.
