Divide, MT frost dates
Last spring frostJun 10median date
First fall frostSep 7median date
Growing season89 daysfrost-free
Hardiness zone5aZone 5a
How Divide compares
- In 8 years out of 10, the last spring frost in Divide falls between May 23 and July 2, a 40-day window. The first fall frost falls between August 24 and September 20.
- The median last frost is 22 days later than the Montana median of May 19.
- Its 89-day growing season is longer than 4% of the 325 Montana places with a regular frost season (state median 125 days).
- The last frost is 38 days later than the zone 5a median of May 3. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 5a chart.
- The weather station records an average of 223 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 23 |
| 50% (median) | June 10 |
| 10% (safe for tender plants) | July 2 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | August 24 |
| 50% (median) | September 7 |
| 90% (late) | September 20 |
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 Divide, MT
Divide, MT frost dates — last frost Jun 10, first frost Sep 7, zone 5a. whenisthelastfrost.com
Crop
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Start indoors: Mar 18 to Apr 1Transplant outside: May 13 to May 27
Start indoors: Apr 1 to Apr 15Transplant outside: Jun 24 to Jul 8
Start indoors: Apr 1 to Apr 15Transplant outside: Jun 24 to Jul 8
Start indoors: Apr 15 to Apr 29Transplant outside: Jun 17 to Jul 1
Start indoors: Apr 15 to Apr 29Transplant outside: May 20 to Jun 3Sow outdoors: May 13 to Jun 17Plant for fall: Jul 13 to Aug 10
Start indoors: Apr 15 to Apr 29Transplant outside: May 13 to May 27Sow outdoors: May 13 to May 27Plant for fall: Jun 29 to Jul 20
Start indoors: Apr 15 to Apr 29Transplant outside: May 27 to Jun 10
Start indoors: Apr 15 to Apr 29Transplant outside: May 20 to Jun 3
Start indoors: Apr 15 to Apr 29Transplant outside: May 27 to Jun 10
Start indoors: Apr 29 to May 13Transplant outside: Jul 1 to Jul 15Sow outdoors: Jul 1 to Jul 15
Start indoors: Apr 29 to May 13Transplant outside: Jun 17 to Jul 1
Sow outdoors: Apr 29 to May 20
Sow outdoors: Apr 29 to May 20Plant for fall: Jul 13 to Aug 3
Sow outdoors: May 6 to Jun 17Plant for fall: Jul 27 to Aug 17
Start indoors: May 13 to May 20Transplant outside: Jun 24 to Jul 1Sow outdoors: Jun 17 to Jul 1
Start indoors: May 13 to May 20Sow outdoors: Jun 17 to Jul 1
Start indoors: May 13 to May 20Sow outdoors: Jun 17 to Jul 1
Start indoors: May 13 to May 20Transplant outside: Jun 24 to Jul 8
Sow outdoors: May 20 to Jun 17
Sow outdoors: May 20 to Jun 17
Sow outdoors: May 20 to Jun 10
Sow outdoors: May 27 to Jun 24
Sow outdoors: May 27 to Jun 17Plant for fall: Jul 13 to Aug 3
Sow outdoors: Jun 17 to Jul 8
Sow outdoors: Jun 17 to Jul 1
Transplant outside: Jun 24 to Jul 15
Plant for fall: Aug 24 to Sep 28
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Divide, MT
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Mar 18 – Apr 1 | May 13 – May 27 | — | — |
| Peppers | Apr 1 – Apr 15 | Jun 24 – Jul 8 | — | — |
| Eggplant | Apr 1 – Apr 15 | Jun 24 – Jul 8 | — | — |
| Tomatoes | Apr 15 – Apr 29 | Jun 17 – Jul 1 | — | — |
| Lettuce | Apr 15 – Apr 29 | May 20 – Jun 3 | May 13 – Jun 17 | Jul 13 – Aug 10 |
| Kale | Apr 15 – Apr 29 | May 13 – May 27 | May 13 – May 27 | Jun 29 – Jul 20 |
| Broccoli | Apr 15 – Apr 29 | May 27 – Jun 10 | — | — |
| Cabbage | Apr 15 – Apr 29 | May 20 – Jun 3 | — | — |
| Cauliflower | Apr 15 – Apr 29 | May 27 – Jun 10 | — | — |
| Okra | Apr 29 – May 13 | Jul 1 – Jul 15 | Jul 1 – Jul 15 | — |
| Basil | Apr 29 – May 13 | Jun 17 – Jul 1 | — | — |
| Peas | — | — | Apr 29 – May 20 | — |
| Spinach | — | — | Apr 29 – May 20 | Jul 13 – Aug 3 |
| Radishes | — | — | May 6 – Jun 17 | Jul 27 – Aug 17 |
| Cucumbers | May 13 – May 20 | Jun 24 – Jul 1 | Jun 17 – Jul 1 | — |
| Zucchini & Summer Squash | May 13 – May 20 | — | Jun 17 – Jul 1 | — |
| Winter Squash & Pumpkins Warning: Your frost-free season is about 89 days, which is tight for winter squash & pumpkins (100+ days). Choose early varieties and use transplants or row covers. | May 13 – May 20 | — | Jun 17 – Jul 1 | — |
| Melons & Watermelon Warning: Your frost-free season is about 89 days, which is tight for melons & watermelon (85+ days). Choose early varieties and use transplants or row covers. | May 13 – May 20 | Jun 24 – Jul 8 | — | — |
| Carrots | — | — | May 20 – Jun 17 | — |
| Beets | — | — | May 20 – Jun 17 | — |
| Potatoes | — | — | May 20 – Jun 10 | — |
| Swiss Chard | — | — | May 27 – Jun 24 | — |
| Cilantro | — | — | May 27 – Jun 17 | Jul 13 – Aug 3 |
| Green Beans | — | — | Jun 17 – Jul 8 | — |
| Sweet Corn Warning: Your frost-free season is about 89 days, which is tight for sweet corn (80+ days). Choose early varieties and use transplants or row covers. | — | — | Jun 17 – Jul 1 | — |
| Sweet Potatoes Warning: Your frost-free season is about 89 days, which is tight for sweet potatoes (100+ days). Choose early varieties and use transplants or row covers. | — | Jun 24 – Jul 15 | — | — |
| Garlic | — | — | — | Aug 24 – Sep 28 |
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 Divide, MT weather station, 7 km away (elevation 5,351 ft (1,631 m)).
Frost dates near Divide
- Wise River frost any month
- Melrose frost any month
- Butte Jun 13 · Sep 5
- Ramsay Jun 13 · Sep 5
- Glen frost any month
- Anaconda Jun 1 · Sep 14
- Warm Springs Jun 1 · Sep 14
- Silver Star Jun 8 · Sep 2
- Twin Bridges Jun 8 · Sep 2
- Whitehall Jun 13 · Sep 5
Frequently asked questions
When is the last frost in Divide, MT?
The median last spring frost in Divide, MT is June 10. There is still about a 10% chance of frost after July 2, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Divide, MT?
The median first fall frost is September 7, with about a 10% chance of frost before August 24.
How long is the growing season in Divide, MT?
About 89 days between the median last spring frost and first fall frost.
What planting zone is Divide, MT?
Divide, MT is in USDA hardiness zone 5a.