Frost dates for 59804 — Missoula, MT
Last spring frostMay 16median date
First fall frostSep 26median date
Growing season133 daysfrost-free
Hardiness zone5bZone 5b
How Missoula compares
- In 8 years out of 10, the last spring frost in Missoula falls between May 3 and June 1, a 29-day window. The first fall frost falls between September 12 and October 8.
- The median last frost is 3 days earlier than the Montana median of May 19.
- Its 133-day growing season is longer than 66% of the 325 Montana places with a regular frost season (state median 125 days).
- The last frost is 15 days later than the zone 5b median of May 1. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 5b chart.
- The weather station records an average of 173 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 3 |
| 50% (median) | May 16 |
| 10% (safe for tender plants) | June 1 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 12 |
| 50% (median) | September 26 |
| 90% (late) | October 8 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Missoula, MT
Frost dates for 59804 — Missoula, MT — last frost May 16, first frost Sep 26, zone 5b. whenisthelastfrost.com
Crop
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Start indoors: Feb 21 to Mar 7Transplant outside: Apr 18 to May 2
Start indoors: Mar 7 to Mar 21Transplant outside: May 30 to Jun 13
Start indoors: Mar 7 to Mar 21Transplant outside: May 30 to Jun 13
Start indoors: Mar 21 to Apr 4Transplant outside: May 23 to Jun 6
Start indoors: Mar 21 to Apr 4Transplant outside: Apr 25 to May 9Sow outdoors: Apr 18 to May 23Plant for fall: Aug 1 to Aug 29
Start indoors: Mar 21 to Apr 4Transplant outside: Apr 18 to May 2Sow outdoors: Apr 18 to May 2Plant for fall: Jul 18 to Aug 8
Start indoors: Mar 21 to Apr 4Transplant outside: May 2 to May 16Plant for fall: Jun 20 to Jul 11
Start indoors: Mar 21 to Apr 4Transplant outside: Apr 25 to May 9Plant for fall: Jun 20 to Jul 11
Start indoors: Mar 21 to Apr 4Transplant outside: May 2 to May 16Plant for fall: Jun 20 to Jul 11
Start indoors: Apr 4 to Apr 18Transplant outside: Jun 6 to Jun 20Sow outdoors: Jun 6 to Jun 20
Start indoors: Apr 4 to Apr 18Transplant outside: May 23 to Jun 6
Sow outdoors: Apr 4 to Apr 25Plant for fall: Jul 4 to Jul 25
Sow outdoors: Apr 4 to Apr 25Plant for fall: Aug 1 to Aug 22
Sow outdoors: Apr 11 to May 23Plant for fall: Aug 15 to Sep 5
Start indoors: Apr 18 to Apr 25Transplant outside: May 30 to Jun 6Sow outdoors: May 23 to Jun 6Plant for fall: Jul 11 to Jul 25
Start indoors: Apr 18 to Apr 25Sow outdoors: May 23 to Jun 6Plant for fall: Jul 18 to Aug 1
Start indoors: Apr 18 to Apr 25Sow outdoors: May 23 to Jun 6
Start indoors: Apr 18 to Apr 25Transplant outside: May 30 to Jun 13
Sow outdoors: Apr 25 to May 23Plant for fall: Jul 4 to Jul 18
Sow outdoors: Apr 25 to May 23Plant for fall: Jul 18 to Aug 1
Sow outdoors: Apr 25 to May 16
Sow outdoors: May 2 to May 30Plant for fall: Jul 18 to Aug 1
Sow outdoors: May 2 to May 23Plant for fall: Aug 1 to Aug 22
Sow outdoors: May 23 to Jun 13Plant for fall: Jul 11 to Jul 25
Sow outdoors: May 23 to Jun 6
Transplant outside: May 30 to Jun 20
Plant for fall: Sep 12 to Oct 17
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Missoula, MT
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 21 – Mar 7 | Apr 18 – May 2 | — | — |
| Peppers | Mar 7 – Mar 21 | May 30 – Jun 13 | — | — |
| Eggplant | Mar 7 – Mar 21 | May 30 – Jun 13 | — | — |
| Tomatoes | Mar 21 – Apr 4 | May 23 – Jun 6 | — | — |
| Lettuce | Mar 21 – Apr 4 | Apr 25 – May 9 | Apr 18 – May 23 | Aug 1 – Aug 29 |
| Kale | Mar 21 – Apr 4 | Apr 18 – May 2 | Apr 18 – May 2 | Jul 18 – Aug 8 |
| Broccoli | Mar 21 – Apr 4 | May 2 – May 16 | — | Jun 20 – Jul 11 |
| Cabbage | Mar 21 – Apr 4 | Apr 25 – May 9 | — | Jun 20 – Jul 11 |
| Cauliflower | Mar 21 – Apr 4 | May 2 – May 16 | — | Jun 20 – Jul 11 |
| Okra | Apr 4 – Apr 18 | Jun 6 – Jun 20 | Jun 6 – Jun 20 | — |
| Basil | Apr 4 – Apr 18 | May 23 – Jun 6 | — | — |
| Peas | — | — | Apr 4 – Apr 25 | Jul 4 – Jul 25 |
| Spinach | — | — | Apr 4 – Apr 25 | Aug 1 – Aug 22 |
| Radishes | — | — | Apr 11 – May 23 | Aug 15 – Sep 5 |
| Cucumbers | Apr 18 – Apr 25 | May 30 – Jun 6 | May 23 – Jun 6 | Jul 11 – Jul 25 |
| Zucchini & Summer Squash | Apr 18 – Apr 25 | — | May 23 – Jun 6 | Jul 18 – Aug 1 |
| Winter Squash & Pumpkins | Apr 18 – Apr 25 | — | May 23 – Jun 6 | — |
| Melons & Watermelon | Apr 18 – Apr 25 | May 30 – Jun 13 | — | — |
| Carrots | — | — | Apr 25 – May 23 | Jul 4 – Jul 18 |
| Beets | — | — | Apr 25 – May 23 | Jul 18 – Aug 1 |
| Potatoes | — | — | Apr 25 – May 16 | — |
| Swiss Chard | — | — | May 2 – May 30 | Jul 18 – Aug 1 |
| Cilantro | — | — | May 2 – May 23 | Aug 1 – Aug 22 |
| Green Beans | — | — | May 23 – Jun 13 | Jul 11 – Jul 25 |
| Sweet Corn | — | — | May 23 – Jun 6 | — |
| Sweet Potatoes | — | May 30 – Jun 20 | — | — |
| Garlic | — | — | — | Sep 12 – Oct 17 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Missoula Intl Ap, MT weather station, 10 km away (elevation 3,192 ft (973 m)).
ZIP codes in Missoula: 59801 59802 59803 59804 59806 59807 59808 59812
Frost dates near Missoula
- Lolo May 16 · Sep 26
- Milltown May 10 · Oct 1
- Bonner May 10 · Oct 1
- Frenchtown May 18 · Sep 25
- Florence May 22 · Sep 19
- Alberton May 18 · Sep 25
- Huson May 18 · Sep 25
- Clinton frost any month
Frequently asked questions
When is the last frost in Missoula, MT?
The median last spring frost in Missoula, MT is May 16. There is still about a 10% chance of frost after June 1, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Missoula, MT?
The median first fall frost is September 26, with about a 10% chance of frost before September 12.
How long is the growing season in Missoula, MT?
About 133 days between the median last spring frost and first fall frost.
What planting zone is Missoula, MT?
Missoula, MT is in USDA hardiness zone 5b.