Wilsall, MT frost dates
Last spring frostJun 4median date
First fall frostSep 6median date
Growing season94 daysfrost-free
Hardiness zone4bZone 4b
How Wilsall compares
- In 8 years out of 10, the last spring frost in Wilsall falls between May 19 and June 23, a 35-day window. The first fall frost falls between August 28 and September 15.
- The median last frost is 16 days later than the Montana median of May 19.
- Its 94-day growing season is longer than 8% of the 325 Montana places with a regular frost season (state median 125 days).
- The last frost is 27 days later than the zone 4b median of May 8. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 4b chart.
- The weather station records an average of 220 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 19 |
| 50% (median) | June 4 |
| 10% (safe for tender plants) | June 23 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | August 28 |
| 50% (median) | September 6 |
| 90% (late) | September 15 |
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 Wilsall, MT
Wilsall, MT frost dates — last frost Jun 4, first frost Sep 6, zone 4b. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Mar 12 to Mar 26Transplant outside: May 7 to May 21
Start indoors: Mar 26 to Apr 9Transplant outside: Jun 18 to Jul 2
Start indoors: Mar 26 to Apr 9Transplant outside: Jun 18 to Jul 2
Start indoors: Apr 9 to Apr 23Transplant outside: Jun 11 to Jun 25
Start indoors: Apr 9 to Apr 23Transplant outside: May 14 to May 28Sow outdoors: May 7 to Jun 11Plant for fall: Jul 12 to Aug 9
Start indoors: Apr 9 to Apr 23Transplant outside: May 7 to May 21Sow outdoors: May 7 to May 21Plant for fall: Jun 28 to Jul 19
Start indoors: Apr 9 to Apr 23Transplant outside: May 21 to Jun 4
Start indoors: Apr 9 to Apr 23Transplant outside: May 14 to May 28
Start indoors: Apr 9 to Apr 23Transplant outside: May 21 to Jun 4
Start indoors: Apr 23 to May 7Transplant outside: Jun 25 to Jul 9Sow outdoors: Jun 25 to Jul 9
Start indoors: Apr 23 to May 7Transplant outside: Jun 11 to Jun 25
Sow outdoors: Apr 23 to May 14
Sow outdoors: Apr 23 to May 14Plant for fall: Jul 12 to Aug 2
Sow outdoors: Apr 30 to Jun 11Plant for fall: Jul 26 to Aug 16
Start indoors: May 7 to May 14Transplant outside: Jun 18 to Jun 25Sow outdoors: Jun 11 to Jun 25
Start indoors: May 7 to May 14Sow outdoors: Jun 11 to Jun 25
Start indoors: May 7 to May 14Sow outdoors: Jun 11 to Jun 25
Start indoors: May 7 to May 14Transplant outside: Jun 18 to Jul 2
Sow outdoors: May 14 to Jun 11
Sow outdoors: May 14 to Jun 11Plant for fall: Jun 28 to Jul 12
Sow outdoors: May 14 to Jun 4
Sow outdoors: May 21 to Jun 18
Sow outdoors: May 21 to Jun 11Plant for fall: Jul 12 to Aug 2
Sow outdoors: Jun 11 to Jul 2
Sow outdoors: Jun 11 to Jun 25
Transplant outside: Jun 18 to Jul 9
Plant for fall: Aug 23 to Sep 27
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Wilsall, MT
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Mar 12 – Mar 26 | May 7 – May 21 | — | — |
| Peppers | Mar 26 – Apr 9 | Jun 18 – Jul 2 | — | — |
| Eggplant | Mar 26 – Apr 9 | Jun 18 – Jul 2 | — | — |
| Tomatoes | Apr 9 – Apr 23 | Jun 11 – Jun 25 | — | — |
| Lettuce | Apr 9 – Apr 23 | May 14 – May 28 | May 7 – Jun 11 | Jul 12 – Aug 9 |
| Kale | Apr 9 – Apr 23 | May 7 – May 21 | May 7 – May 21 | Jun 28 – Jul 19 |
| Broccoli | Apr 9 – Apr 23 | May 21 – Jun 4 | — | — |
| Cabbage | Apr 9 – Apr 23 | May 14 – May 28 | — | — |
| Cauliflower | Apr 9 – Apr 23 | May 21 – Jun 4 | — | — |
| Okra | Apr 23 – May 7 | Jun 25 – Jul 9 | Jun 25 – Jul 9 | — |
| Basil | Apr 23 – May 7 | Jun 11 – Jun 25 | — | — |
| Peas | — | — | Apr 23 – May 14 | — |
| Spinach | — | — | Apr 23 – May 14 | Jul 12 – Aug 2 |
| Radishes | — | — | Apr 30 – Jun 11 | Jul 26 – Aug 16 |
| Cucumbers | May 7 – May 14 | Jun 18 – Jun 25 | Jun 11 – Jun 25 | — |
| Zucchini & Summer Squash | May 7 – May 14 | — | Jun 11 – Jun 25 | — |
| Winter Squash & Pumpkins Warning: Your frost-free season is about 94 days, which is tight for winter squash & pumpkins (100+ days). Choose early varieties and use transplants or row covers. | May 7 – May 14 | — | Jun 11 – Jun 25 | — |
| Melons & Watermelon Warning: Your frost-free season is about 94 days, which is tight for melons & watermelon (85+ days). Choose early varieties and use transplants or row covers. | May 7 – May 14 | Jun 18 – Jul 2 | — | — |
| Carrots | — | — | May 14 – Jun 11 | — |
| Beets | — | — | May 14 – Jun 11 | Jun 28 – Jul 12 |
| Potatoes | — | — | May 14 – Jun 4 | — |
| Swiss Chard | — | — | May 21 – Jun 18 | — |
| Cilantro | — | — | May 21 – Jun 11 | Jul 12 – Aug 2 |
| Green Beans | — | — | Jun 11 – Jul 2 | — |
| Sweet Corn | — | — | Jun 11 – Jun 25 | — |
| Sweet Potatoes Warning: Your frost-free season is about 94 days, which is tight for sweet potatoes (100+ days). Choose early varieties and use transplants or row covers. | — | Jun 18 – Jul 9 | — | — |
| Garlic | — | — | — | Aug 23 – Sep 27 |
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 Wilsall 1s, MT weather station, 6 km away (elevation 5,016 ft (1,529 m)).
Frost dates near Wilsall
- Clyde Park Jun 4 · Sep 6
- Livingston May 27 · Sep 14
- Springdale May 27 · Sep 14
- Ringling frost any month
- Belgrade May 26 · Sep 16
- Bozeman May 26 · Sep 22
- Big Timber May 14 · Sep 26
- Manhattan May 26 · Sep 15
- Martinsdale Jun 3 · Sep 8
- Mc Leod Jun 1 · Sep 11
Frequently asked questions
When is the last frost in Wilsall, MT?
The median last spring frost in Wilsall, MT is June 4. There is still about a 10% chance of frost after June 23, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Wilsall, MT?
The median first fall frost is September 6, with about a 10% chance of frost before August 28.
How long is the growing season in Wilsall, MT?
About 94 days between the median last spring frost and first fall frost.
What planting zone is Wilsall, MT?
Wilsall, MT is in USDA hardiness zone 4b.