‘Sub-freezing temperatures’ forecast in Treasure Valley. How to protect your home
Parts of Southwest Idaho will see “sub-freezing temperatures as a strong low-pressure series moves through the state,” according to the National Weather Service.
On Wednesday, April 15, the weather service’s Boise office issued a pair of freeze warnings. Temperatures are expected to plunge as low as 28 degrees in parts of the Treasure Valley, with the Snake Plain seeing 24-degree lows.
Although below-freezing temperatures could begin Thursday, April 16, “the coldest period” will be later in the week, the weather service said in its most recent Idaho state forecast discussion.
Here’s how to prepare:
How long will freezing temperatures last?
The National Weather Service’s first freeze warning will remain in effect from 4 a.m. to 10 a.m. on Thursday.
The weather service warned of temperatures as low as 30 degrees in the lower Treasure Valley and 28 degrees in the upper Treasure Valley and western Magic Valley.
Another freeze warning goes into effect for the Snake Plain in Southwest Idaho and southeast Oregon from midnight to 10 a.m. on Friday, April 17.
“Sub-freezing temperatures as low as 24 to 28 degrees are expected,” the weather service said.
Forecasters urged area residents to “take steps now to protect tender plants from the cold.”
“Frost and freeze conditions could kill crops, other sensitive vegetation and possibly damage unprotected outdoor plumbing,” the weather service said in its warning.
How cold will it get in Boise?
According to the National Weather Service’s latest forecast for Boise, the city was expected to see rain showers mixing with snow on Wednesday night, when the low will drop to 32 degrees.
The low will drop to 28 degrees on Thursday night.
A thunderstorm complete with downpours and hail blew through the area just after 6 p.m. Wednesday.
How can I keep my plants safe?
According to the National Weather Service, freezing temperatures could “kill or damage” local crops and gardens.
“While it’s normal for the Snake Plain to see freezes through mid-May, the recent long warm spell has triggered early blooming,” the weather agency said.
“The primary way to protect plants from frosts is to cover them with a blanket or row cover,” the Old Farmer’s Almanac said. “It’s worth the time to cover your crops because sometimes an early freeze is a freak incident, and there are many days of great weather to follow.”
Avoid letting materials rest directly on your plants by using “rocks, bricks and stakes,” the almanac said.
The Old Farmer’s Almanac advised using mulch, straw and leaf foliage to cover root vegetables and plants that grow close to the ground.
How can I avoid plumbing damage?
“When water inside pipes freezes, it expands, leading to increased pressure that can cause pipes to crack or burst,” Treasure Valley business Western said.
The company provides heating, air conditioning, electrical and plumbing services in Boise, Merdian and other cities.
To avoid damage to pipes, especially those outside your home, Western recommends taking these steps:
- Set your thermostat no lower than 55 degrees.
- Trickle warm water through your faucets.
- Keep cabinetry open to allow warm air flow near pipes.
- Use pipe insulation or heat tape to protect outdoor pipes.
- Protect water heaters, especially older ones, with an insulated blanket.
- Seal up any leaks or cracks.
- Make sure your garden hose is empty and turn off and cover your outdoor water spout.
- Ensure your garage door remains shut.
When will cold weather end?
Although low temperatures in Boise should rise above freezing beginning Friday night, the weather service said, the Treasure Valley can expect sudden freezes until later in May.
This story was originally published April 15, 2026 at 5:47 PM.
