Southwest Idaho is heading into a hot and active weekend, with triple-digit temperatures expected in some areas and storm chances rising soon after. Cities like Boise, Nampa, Caldwell, and Mountain Home are all in for extreme heat, especially on Saturday, when the mercury could touch or cross 99°F.
The National Weather Service in Boise has issued heat and storm advisories, warning locals to take care as dangerous heat levels build through the weekend. Then, by Saturday evening into Sunday, monsoonal moisture will bring the risk of thunderstorms, especially in the mountains and central Idaho.
Saturday: Hottest Day of the Week
Saturday will be the peak of the heat wave, with many places nearing 100°F. Extended exposure to this kind of heat can cause heat exhaustion, dehydration, or worse.
People are advised to:
Avoid strenuous activities during peak hours (12–5 PM)
Drink lots of water, even if you’re not thirsty
Stay in shaded or air-conditioned areas
Check on the elderly, kids, and pets who are more vulnerable
Sunday and Beyond: Storm Chances Increase
After the heat peaks Saturday, monsoon moisture will start creeping in from the south. That means a growing risk of showers and thunderstorms, starting Saturday evening and continuing through Sunday, Monday, and even into midweek.
Expected storm impacts include:
Lightning and strong wind gusts
Sudden downpours causing slick roads
Quick weather changes, especially in mountain areas like:
McCall
Stanley
Sun Valley
If you’re planning any camping, hiking, or road trips, especially in the backcountry, be ready for changing weather — from sunshine to storms in minutes.
Tips for Staying Safe This Weekend
With a mix of extreme heat and pop-up storms, here’s how to stay safe:
Download a weather app for real-time alerts
Postpone non-essential outdoor plans during peak heat hours
Keep emergency kits if travelling to higher elevations
Secure tents and equipment if camping; gusty winds may develop fast
If you hear thunder, head indoors — lightning can strike even if it’s not raining
Five-Day Forecast for Boise, Idaho
| Day | Forecast | High Temp |
|---|---|---|
| Thursday | Sunny and dry | 92°F |
| Friday | Mostly sunny, hot | 96°F |
| Saturday | Hot, storms possible late | 99°F |
| Sunday | Scattered storms likely | 96°F |
| Monday | Increased storm chances | 94°F |
Looking Ahead
Storm chances are expected to linger through Wednesday, with isolated showers possible each day. Though not everyone will get rain, it’s important to plan for the possibility, especially if you’re spending time outdoors or in remote areas.
