Miles City, MT frost dates
Last spring frostMay 8median date
First fall frostSep 30median date
Growing season145 daysfrost-free
Hardiness zone4bZone 4b
How Miles City compares
- In 8 years out of 10, the last spring frost in Miles City falls between April 26 and May 21, a 25-day window. The first fall frost falls between September 17 and October 14.
- The median last frost is 11 days earlier than the Montana median of May 19.
- Its 145-day growing season is longer than 90% of the 325 Montana places with a regular frost season (state median 125 days).
- The last frost is typical for zone 4b, where the median is May 8.
- The weather station records an average of 166 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 26 |
| 50% (median) | May 8 |
| 10% (safe for tender plants) | May 21 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 17 |
| 50% (median) | September 30 |
| 90% (late) | October 14 |
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 Miles City, MT
Miles City, MT frost dates — last frost May 8, first frost Sep 30, zone 4b. whenisthelastfrost.com
Crop
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Start indoors: Feb 13 to Feb 27Transplant outside: Apr 10 to Apr 24
Start indoors: Feb 27 to Mar 13Transplant outside: May 22 to Jun 5
Start indoors: Feb 27 to Mar 13Transplant outside: May 22 to Jun 5
Start indoors: Mar 13 to Mar 27Transplant outside: May 15 to May 29
Start indoors: Mar 13 to Mar 27Transplant outside: Apr 17 to May 1Sow outdoors: Apr 10 to May 15Plant for fall: Aug 5 to Sep 2
Start indoors: Mar 13 to Mar 27Transplant outside: Apr 10 to Apr 24Sow outdoors: Apr 10 to Apr 24Plant for fall: Jul 22 to Aug 12
Start indoors: Mar 13 to Mar 27Transplant outside: Apr 24 to May 8Plant for fall: Jun 24 to Jul 15
Start indoors: Mar 13 to Mar 27Transplant outside: Apr 17 to May 1Plant for fall: Jun 24 to Jul 15
Start indoors: Mar 13 to Mar 27Transplant outside: Apr 24 to May 8Plant for fall: Jun 24 to Jul 15
Start indoors: Mar 27 to Apr 10Transplant outside: May 29 to Jun 12Sow outdoors: May 29 to Jun 12
Start indoors: Mar 27 to Apr 10Transplant outside: May 15 to May 29
Sow outdoors: Mar 27 to Apr 17Plant for fall: Jul 8 to Jul 29
Sow outdoors: Mar 27 to Apr 17Plant for fall: Aug 5 to Aug 26
Sow outdoors: Apr 3 to May 15Plant for fall: Aug 19 to Sep 9
Start indoors: Apr 10 to Apr 17Transplant outside: May 22 to May 29Sow outdoors: May 15 to May 29Plant for fall: Jul 15 to Jul 29
Start indoors: Apr 10 to Apr 17Sow outdoors: May 15 to May 29Plant for fall: Jul 22 to Aug 5
Start indoors: Apr 10 to Apr 17Sow outdoors: May 15 to May 29
Start indoors: Apr 10 to Apr 17Transplant outside: May 22 to Jun 5
Sow outdoors: Apr 17 to May 15Plant for fall: Jul 8 to Jul 22
Sow outdoors: Apr 17 to May 15Plant for fall: Jul 22 to Aug 5
Sow outdoors: Apr 17 to May 8
Sow outdoors: Apr 24 to May 22Plant for fall: Jul 22 to Aug 5
Sow outdoors: Apr 24 to May 15Plant for fall: Aug 5 to Aug 26
Sow outdoors: May 15 to Jun 5Plant for fall: Jul 15 to Jul 29
Sow outdoors: May 15 to May 29
Transplant outside: May 22 to Jun 12
Plant for fall: Sep 16 to Oct 21
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Miles City, MT
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 13 – Feb 27 | Apr 10 – Apr 24 | — | — |
| Peppers | Feb 27 – Mar 13 | May 22 – Jun 5 | — | — |
| Eggplant | Feb 27 – Mar 13 | May 22 – Jun 5 | — | — |
| Tomatoes | Mar 13 – Mar 27 | May 15 – May 29 | — | — |
| Lettuce | Mar 13 – Mar 27 | Apr 17 – May 1 | Apr 10 – May 15 | Aug 5 – Sep 2 |
| Kale | Mar 13 – Mar 27 | Apr 10 – Apr 24 | Apr 10 – Apr 24 | Jul 22 – Aug 12 |
| Broccoli | Mar 13 – Mar 27 | Apr 24 – May 8 | — | Jun 24 – Jul 15 |
| Cabbage | Mar 13 – Mar 27 | Apr 17 – May 1 | — | Jun 24 – Jul 15 |
| Cauliflower | Mar 13 – Mar 27 | Apr 24 – May 8 | — | Jun 24 – Jul 15 |
| Okra | Mar 27 – Apr 10 | May 29 – Jun 12 | May 29 – Jun 12 | — |
| Basil | Mar 27 – Apr 10 | May 15 – May 29 | — | — |
| Peas | — | — | Mar 27 – Apr 17 | Jul 8 – Jul 29 |
| Spinach | — | — | Mar 27 – Apr 17 | Aug 5 – Aug 26 |
| Radishes | — | — | Apr 3 – May 15 | Aug 19 – Sep 9 |
| Cucumbers | Apr 10 – Apr 17 | May 22 – May 29 | May 15 – May 29 | Jul 15 – Jul 29 |
| Zucchini & Summer Squash | Apr 10 – Apr 17 | — | May 15 – May 29 | Jul 22 – Aug 5 |
| Winter Squash & Pumpkins | Apr 10 – Apr 17 | — | May 15 – May 29 | — |
| Melons & Watermelon | Apr 10 – Apr 17 | May 22 – Jun 5 | — | — |
| Carrots | — | — | Apr 17 – May 15 | Jul 8 – Jul 22 |
| Beets | — | — | Apr 17 – May 15 | Jul 22 – Aug 5 |
| Potatoes | — | — | Apr 17 – May 8 | — |
| Swiss Chard | — | — | Apr 24 – May 22 | Jul 22 – Aug 5 |
| Cilantro | — | — | Apr 24 – May 15 | Aug 5 – Aug 26 |
| Green Beans | — | — | May 15 – Jun 5 | Jul 15 – Jul 29 |
| Sweet Corn | — | — | May 15 – May 29 | — |
| Sweet Potatoes | — | May 22 – Jun 12 | — | — |
| Garlic | — | — | — | Sep 16 – Oct 21 |
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 Miles City F Wiley Fld, MT weather station, 4 km away (elevation 2,625 ft (800 m)).
Frost dates near Miles City
- Kinsey May 8 · Sep 30
- Hathaway May 8 · Sep 30
- Rosebud May 9 · Sep 29
- Angela May 15 · Sep 25
- Ismay May 22 · Sep 15
- Terry May 12 · Sep 28
- Volborg May 18 · Sep 22
- Forsyth May 9 · Sep 29
- Fallon May 20 · Sep 22
- Mildred May 20 · Sep 22
Frequently asked questions
When is the last frost in Miles City, MT?
The median last spring frost in Miles City, MT is May 8. There is still about a 10% chance of frost after May 21, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Miles City, MT?
The median first fall frost is September 30, with about a 10% chance of frost before September 17.
How long is the growing season in Miles City, MT?
About 145 days between the median last spring frost and first fall frost.
What planting zone is Miles City, MT?
Miles City, MT is in USDA hardiness zone 4b.