Frost dates for 59703 — Butte, MT
Last spring frostJun 13median date
First fall frostSep 5median date
Growing season84 daysfrost-free
Hardiness zone4aZone 4a
How Butte compares
- In 8 years out of 10, the last spring frost in Butte falls between May 27 and July 1, a 35-day window. The first fall frost falls between August 24 and September 19.
- The median last frost is 25 days later than the Montana median of May 19.
- Its 84-day growing season is among the shortest of the 325 Montana places with a regular frost season.
- The last frost is 32 days later than the zone 4a median of May 12. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 4a 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 27 |
| 50% (median) | June 13 |
| 10% (safe for tender plants) | July 1 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | August 24 |
| 50% (median) | September 5 |
| 90% (late) | September 19 |
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 Butte, MT
Frost dates for 59703 — Butte, MT — last frost Jun 13, first frost Sep 5, zone 4a. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Mar 21 to Apr 4Transplant outside: May 16 to May 30
Start indoors: Apr 4 to Apr 18Transplant outside: Jun 27 to Jul 11
Start indoors: Apr 4 to Apr 18Transplant outside: Jun 27 to Jul 11
Start indoors: Apr 18 to May 2Transplant outside: Jun 20 to Jul 4
Start indoors: Apr 18 to May 2Transplant outside: May 23 to Jun 6Sow outdoors: May 16 to Jun 20Plant for fall: Jul 11 to Aug 8
Start indoors: Apr 18 to May 2Transplant outside: May 16 to May 30Sow outdoors: May 16 to May 30
Start indoors: Apr 18 to May 2Transplant outside: May 30 to Jun 13
Start indoors: Apr 18 to May 2Transplant outside: May 23 to Jun 6
Start indoors: Apr 18 to May 2Transplant outside: May 30 to Jun 13
Start indoors: May 2 to May 16Transplant outside: Jul 4 to Jul 18Sow outdoors: Jul 4 to Jul 18
Start indoors: May 2 to May 16Transplant outside: Jun 20 to Jul 4
Sow outdoors: May 2 to May 23
Sow outdoors: May 2 to May 23Plant for fall: Jul 11 to Aug 1
Sow outdoors: May 9 to Jun 20Plant for fall: Jul 25 to Aug 15
Start indoors: May 16 to May 23Transplant outside: Jun 27 to Jul 4Sow outdoors: Jun 20 to Jul 4
Start indoors: May 16 to May 23Sow outdoors: Jun 20 to Jul 4
Start indoors: May 16 to May 23Sow outdoors: Jun 20 to Jul 4
Start indoors: May 16 to May 23Transplant outside: Jun 27 to Jul 11
Sow outdoors: May 23 to Jun 20
Sow outdoors: May 23 to Jun 20
Sow outdoors: May 23 to Jun 13
Sow outdoors: May 30 to Jun 27
Sow outdoors: May 30 to Jun 20Plant for fall: Jul 11 to Aug 1
Sow outdoors: Jun 20 to Jul 11
Sow outdoors: Jun 20 to Jul 4
Transplant outside: Jun 27 to Jul 18
Plant for fall: Aug 22 to Sep 26
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Butte, MT
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Mar 21 – Apr 4 | May 16 – May 30 | — | — |
| Peppers Warning: Your frost-free season is about 84 days, which is tight for peppers (75+ days). Choose early varieties and use transplants or row covers. | Apr 4 – Apr 18 | Jun 27 – Jul 11 | — | — |
| Eggplant Warning: Your frost-free season is about 84 days, which is tight for eggplant (75+ days). Choose early varieties and use transplants or row covers. | Apr 4 – Apr 18 | Jun 27 – Jul 11 | — | — |
| Tomatoes | Apr 18 – May 2 | Jun 20 – Jul 4 | — | — |
| Lettuce | Apr 18 – May 2 | May 23 – Jun 6 | May 16 – Jun 20 | Jul 11 – Aug 8 |
| Kale | Apr 18 – May 2 | May 16 – May 30 | May 16 – May 30 | — |
| Broccoli | Apr 18 – May 2 | May 30 – Jun 13 | — | — |
| Cabbage | Apr 18 – May 2 | May 23 – Jun 6 | — | — |
| Cauliflower | Apr 18 – May 2 | May 30 – Jun 13 | — | — |
| Okra | May 2 – May 16 | Jul 4 – Jul 18 | Jul 4 – Jul 18 | — |
| Basil | May 2 – May 16 | Jun 20 – Jul 4 | — | — |
| Peas | — | — | May 2 – May 23 | — |
| Spinach | — | — | May 2 – May 23 | Jul 11 – Aug 1 |
| Radishes | — | — | May 9 – Jun 20 | Jul 25 – Aug 15 |
| Cucumbers | May 16 – May 23 | Jun 27 – Jul 4 | Jun 20 – Jul 4 | — |
| Zucchini & Summer Squash | May 16 – May 23 | — | Jun 20 – Jul 4 | — |
| Winter Squash & Pumpkins Warning: Your frost-free season is about 84 days, which is tight for winter squash & pumpkins (100+ days). Choose early varieties and use transplants or row covers. | May 16 – May 23 | — | Jun 20 – Jul 4 | — |
| Melons & Watermelon Warning: Your frost-free season is about 84 days, which is tight for melons & watermelon (85+ days). Choose early varieties and use transplants or row covers. | May 16 – May 23 | Jun 27 – Jul 11 | — | — |
| Carrots | — | — | May 23 – Jun 20 | — |
| Beets | — | — | May 23 – Jun 20 | — |
| Potatoes | — | — | May 23 – Jun 13 | — |
| Swiss Chard | — | — | May 30 – Jun 27 | — |
| Cilantro | — | — | May 30 – Jun 20 | Jul 11 – Aug 1 |
| Green Beans | — | — | Jun 20 – Jul 11 | — |
| Sweet Corn Warning: Your frost-free season is about 84 days, which is tight for sweet corn (80+ days). Choose early varieties and use transplants or row covers. | — | — | Jun 20 – Jul 4 | — |
| Sweet Potatoes Warning: Your frost-free season is about 84 days, which is tight for sweet potatoes (100+ days). Choose early varieties and use transplants or row covers. | — | Jun 27 – Jul 18 | — | — |
| Garlic | — | — | — | Aug 22 – Sep 26 |
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 Butte Bert Mooney Ap, MT weather station, 12 km away (elevation 5,505 ft (1,678 m)).
ZIP codes in Butte: 59701 59702 59703 59707 59750
Frost dates near Butte
- Ramsay Jun 13 · Sep 5
- Divide Jun 10 · Sep 7
- Melrose frost any month
- Warm Springs Jun 1 · Sep 14
- Wise River frost any month
- Anaconda Jun 1 · Sep 14
- Silver Star Jun 8 · Sep 2
- Whitehall Jun 13 · Sep 5
Frequently asked questions
When is the last frost in Butte, MT?
The median last spring frost in Butte, MT is June 13. There is still about a 10% chance of frost after July 1, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Butte, MT?
The median first fall frost is September 5, with about a 10% chance of frost before August 24.
How long is the growing season in Butte, MT?
About 84 days between the median last spring frost and first fall frost.
What planting zone is Butte, MT?
Butte, MT is in USDA hardiness zone 4a.