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When to plant in Bozeman, MT

USDA Zone 5a

Bozeman, Montana frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.

A ~119-day frost-free window makes Bozeman a short-season garden: choose early varieties and start long-season crops indoors well ahead of the last frost. Zone 5a means Bozeman sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.

Station · BOZEMAN MONTANA STATE UNIV · 2.4 km
Last spring frost
May 26
50% chance · 32°F
First fall frost
September 22
50% chance · 32°F
Growing season
119 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for BozemanA year-band showing 32°F frost risk from January to December for Bozeman: last spring frost around May 26, first fall frost around September 22, about 119 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

The average last spring frost in Bozeman is now 5 days earlier than in the 1981–2010 normals. See how frost dates are shifting nationwide →

Frost probability

BOZEMAN MONTANA STATE UNIV · 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 Bozeman’s own odds, recorded at BOZEMAN MONTANA STATE UNIV.

Frost-probability curves for BozemanProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around May 26 and the first fall frost around September 22, giving about 119 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%
36°FJun 28Jun 14May 28Aug 26Sep 8Sep 23
32°FJun 14May 26May 9Sep 5Sep 22Oct 5
28°FMay 26May 8Apr 23Sep 18Oct 3Oct 19

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
Napa Cabbage
June 30July 28
Fall sowopen now
Beet
July 14July 28
Fall sowopen now
Collards
July 14August 11
Fall sowopen now
Endive
July 14July 28
Fall sowopen now
Escarole
July 14July 28
Fall sowopen now
Fennel (Bulb)
July 14July 28
Fall sowopen now
Kale
July 14August 11
Fall sowopen now
Kohlrabi
July 14August 11
Fall sowopen now
Peas
July 14July 28
Fall sowopen now
Radicchio
July 14July 28
Fall sowopen now
Swiss Chard
July 14July 28
Fall sowopen now
Turnip
July 14August 11
Fall sowin 9 days
Arugula
July 28August 25
Fall sowin 9 days
Bok Choy
July 28August 11
Fall sowin 9 days
Chervil
July 28August 25
Fall sowin 9 days
Cilantro
July 28August 25
Fall sowin 9 days
Claytonia (Miner's Lettuce)
July 28August 25
Fall sowin 9 days
Corn Salad (Mâche)
July 28August 25
Fall sowin 9 days
Gai Lan (Chinese Broccoli)
July 28August 11
Fall sowin 9 days
Lettuce
July 28August 25
Fall sowin 9 days
Mizuna
July 28August 25
Fall sowin 9 days
Mustard Greens
July 28August 25
Fall sowin 9 days
Radish
July 28August 25
Fall sowin 9 days
Shungiku (Edible Chrysanthemum)
July 28August 11
Fall sowin 9 days
Spinach
July 28August 25
Fall sowin 9 days
Tatsoi
July 28August 25

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 Bozeman, drawn to the day from the local frost dates. The dashed line is today.

Nearby weather stations

3 within 14 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.

BOZEMAN MONTANA STATE UNIV
Primary
2 km · 1498 m elevation
SPRING
May 26
FALL
Sep 22
BOZEMAN 6 W EXP FARM
8 km · 1455 m elevation
SPRING
May 23
FALL
Sep 23
BOZEMAN GALLATIN FLD
14 km · 1349 m elevation
SPRING
May 26
FALL
Sep 16

Bozeman planting FAQ

When is the last spring frost in Bozeman, MT?

On average, the last spring frost in Bozeman is around May 26 (50% probability at 32°F, from 1991–2020 NOAA normals). Wait until after this date to set out tender plants like tomatoes and peppers.

When is the first fall frost in Bozeman, MT?

The first fall frost in Bozeman typically arrives around September 22 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.

What hardiness zone is Bozeman in?

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

How long is the growing season in Bozeman?

There are roughly 119 frost-free days in Bozeman (a short growing season), running from the average last frost around May 26 to the first fall frost near September 22.

When should I plant tomatoes in Bozeman?

In Bozeman, start tomato seeds indoors around March 31–April 14, then transplant seedlings outdoors around June 2 once the danger of frost has passed.

Planting reminders

Never miss a window in Bozeman

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

Nearby cities

8 within reach

Frost dates recorded at BOZEMAN MONTANA STATE UNIV, 2 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 Bozeman, MT — Frost Dates & Zone 5a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00241044. Retrieved from https://blissgarden.com/montana/bozeman.