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When to plant in Kalispell, MT

USDA Zone 5b

Here are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Kalispell, Montana — all computed from Kalispell's nearest NOAA weather station.

A ~102-day frost-free window makes Kalispell a short-season garden: choose early varieties and start long-season crops indoors well ahead of the last frost. Zone 5b means Kalispell sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.

Station · KALISPELL GLACIER AP · 10.9 km
Last spring frost
May 31
50% chance · 32°F
First fall frost
September 10
50% chance · 32°F
Growing season
102 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for KalispellA year-band showing 32°F frost risk from January to December for Kalispell: last spring frost around May 31, first fall frost around September 10, about 102 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

Frost probability

KALISPELL GLACIER AP · 1991–2020

The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Kalispell’s own odds, recorded at KALISPELL GLACIER AP.

Frost-probability curves for KalispellProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around May 31 and the first fall frost around September 10, giving about 102 frost-free days.
Last spring frostFirst fall frostbold = 32°F · thin = 28°F / 36°F · dot = 50% date · band = 10–90% window
ThresholdSPRING 10%SPRING 50%SPRING 90%FALL 10%FALL 50%FALL 90%
32°FJun 22May 31May 13Aug 26Sep 10Sep 25
28°FMay 26May 10Apr 28Sep 9Sep 27Oct 7

Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.

What to plant now

TODAY · JULY 19
Fall sowopen now
Collards
July 2July 30
Fall sowopen now
Kale
July 2July 30
Fall sowopen now
Kohlrabi
July 2July 30
Fall sowopen now
Turnip
July 2July 30
Fall sowopen now
Arugula
July 16August 13
Fall sowopen now
Bok Choy
July 16July 30
Fall sowopen now
Chervil
July 16August 13
Fall sowopen now
Cilantro
July 16August 13
Fall sowopen now
Claytonia (Miner's Lettuce)
July 16August 13
Fall sowopen now
Corn Salad (Mâche)
July 16August 13
Fall sowopen now
Gai Lan (Chinese Broccoli)
July 16July 30
Fall sowopen now
Lettuce
July 16August 13
Fall sowopen now
Mizuna
July 16August 13
Fall sowopen now
Mustard Greens
July 16August 13
Fall sowopen now
Radish
July 16August 13
Fall sowopen now
Shungiku (Edible Chrysanthemum)
July 16July 30
Fall sowopen now
Spinach
July 16August 13
Fall sowopen now
Tatsoi
July 16August 13
Fall sowin 25 days
Garlic
August 13August 27
Fall sowin 25 days
Shallot
August 13August 27

Add these crops to your calendar (.ics) ↓

Full-year planting calendar

Start indoorsTransplantDirect sowFall sow

Each bar is the exact window to take a planting action in Kalispell, drawn to the day from the local frost dates. The dashed line is today.

Nearby weather stations

3 within 21 km · complete 32°F normals

When stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.

KALISPELL GLACIER AP
Primary
11 km · 901 m elevation
SPRING
May 31
FALL
Sep 10
CRESTON
15 km · 895 m elevation
SPRING
May 12
FALL
Sep 25
WHITEFISH
21 km · 945 m elevation
SPRING
May 16
FALL
Sep 25

Kalispell planting FAQ

When is the last spring frost in Kalispell, MT?

Plan for the last spring frost in Kalispell around May 31 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.

When is the first fall frost in Kalispell, MT?

The first fall frost in Kalispell typically arrives around September 10 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.

What hardiness zone is Kalispell in?

Kalispell is in USDA hardiness zone 5b. In zone 5b, winters are cold — pick cold-hardy varieties and protect tender crops.

How long is the growing season in Kalispell?

There are roughly 102 frost-free days in Kalispell (a short growing season), running from the average last frost around May 31 to the first fall frost near September 10.

When should I plant tomatoes in Kalispell?

In Kalispell, start tomato seeds indoors around April 5–April 19, then transplant seedlings outdoors around June 7 once the danger of frost has passed.

Planting reminders

Never miss a window in Kalispell

An email when it’s time to start seeds, transplant, and sow — timed to Kalispell’s frost dates. Double opt-in, one-click unsubscribe, no spam.

Nearby cities

8 within reach

Frost dates recorded at KALISPELL GLACIER AP, 11 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.

Cite this page
BlissGarden. "When to Plant in Kalispell, MT — Frost Dates & Zone 5b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00244558. Retrieved from https://blissgarden.com/montana/kalispell.