Frost dates · Montana
Montana counties by frost timing.
Latest at top, earliest at bottom. In most states this matches the north-to-south gradient.
Sorted by spring frost
Latest → earliest.
Beaverhead County
Spring May 30·Fall Sep 14107-day season
Granite County
Spring May 29·Fall Sep 12106-day season
Powell County
Spring May 26·Fall Sep 11108-day season
Jefferson County
Spring May 21·Fall Sep 21123-day season
Silver Bow County
Spring May 21·Fall Sep 17119-day season
Daniels County
Spring May 19·Fall Sep 16120-day season
Glacier County
Spring May 19·Fall Sep 20124-day season
Meagher County
Spring May 18·Fall Sep 25130-day season
Wibaux County
Spring May 17·Fall Sep 26132-day season
Sheridan County
Spring May 15·Fall Sep 22130-day season
Madison County
Spring May 14·Fall Oct 1140-day season
Roosevelt County
Spring May 14·Fall Sep 22131-day season
Teton County
Spring May 14·Fall Sep 25134-day season
Deer Lodge County
Spring May 13·Fall Sep 28138-day season
Stillwater County
Spring May 13·Fall Sep 26136-day season
Hill County
Spring May 12·Fall Sep 26137-day season
Wheatland County
Spring May 12·Fall Sep 27138-day season
Custer County
Spring May 11·Fall Sep 25137-day season
Liberty County
Spring May 11·Fall Sep 26138-day season
Big Horn County
Spring May 10·Fall Sep 28141-day season
Judith Basin County
Spring May 10·Fall Oct 1144-day season
Toole County
Spring May 10·Fall Sep 26139-day season
Chouteau County
Spring May 9·Fall Sep 29143-day season
Garfield County
Spring May 8·Fall Sep 29144-day season
Broadwater County
Spring May 7·Fall Oct 1147-day season
Lewis and Clark County
Spring May 7·Fall Sep 28144-day season
Lincoln County
Spring May 7·Fall Oct 5151-day season
Musselshell County
Spring May 7·Fall Oct 1147-day season
Petroleum County
Spring May 7·Fall Sep 29145-day season
Blaine County
Spring May 6·Fall Sep 30147-day season
Carter County
Spring May 6·Fall Oct 1148-day season
McCone County
Spring May 6·Fall Oct 1148-day season
Golden Valley County
Spring May 5·Fall Oct 3151-day season
Ravalli County
Spring May 5·Fall Oct 4152-day season
Park County
Spring May 4·Fall Oct 5154-day season
Pondera County
Spring May 4·Fall Oct 4153-day season
Powder River County
Spring May 3·Fall Oct 7157-day season
Valley County
Spring May 3·Fall Oct 5155-day season
Fallon County
Spring May 2·Fall Oct 4155-day season
Fergus County
Spring May 2·Fall Oct 6157-day season
Gallatin County
Spring May 2·Fall Oct 3154-day season
Richland County
Spring May 2·Fall Oct 6157-day season
Sweet Grass County
Spring May 2·Fall Oct 5156-day season
Carbon County
Spring May 1·Fall Oct 4156-day season
Mineral County
Spring May 1·Fall Oct 6158-day season
Prairie County
Spring May 1·Fall Oct 5157-day season
Cascade County
Spring Apr 30·Fall Oct 8161-day season
Phillips County
Spring Apr 30·Fall Oct 6159-day season
Treasure County
Spring Apr 30·Fall Oct 7160-day season
Yellowstone County
Spring Apr 30·Fall Oct 4157-day season
Rosebud County
Spring Apr 29·Fall Oct 8162-day season
Lake County
Spring Apr 28·Fall Oct 16171-day season
Missoula County
Spring Apr 28·Fall Oct 12167-day season
Flathead County
Spring Apr 27·Fall Oct 14170-day season
Dawson County
Spring Apr 24·Fall Oct 13172-day season
Alphabetical · A to Z
- Beaverhead County
- Big Horn County
- Blaine County
- Broadwater County
- Carbon County
- Carter County
- Cascade County
- Chouteau County
- Custer County
- Daniels County
- Dawson County
- Deer Lodge County
- Fallon County
- Fergus County
- Flathead County
- Gallatin County
- Garfield County
- Glacier County
- Golden Valley County
- Granite County
- Hill County
- Jefferson County
- Judith Basin County
- Lake County
- Lewis and Clark County
- Liberty County
- Lincoln County
- Madison County
- McCone County
- Meagher County
- Mineral County
- Missoula County
- Musselshell County
- Park County
- Petroleum County
- Phillips County
- Pondera County
- Powder River County
- Powell County
- Prairie County
- Ravalli County
- Richland County
- Roosevelt County
- Rosebud County
- Sanders County
- Sheridan County
- Silver Bow County
- Stillwater County
- Sweet Grass County
- Teton County
- Toole County
- Treasure County
- Valley County
- Wheatland County
- Wibaux County
- Yellowstone County