Ryegate, MT frost dates
Last spring frostMay 17median date
First fall frostSep 23median date
Growing season129 daysfrost-free
Hardiness zone4bZone 4b
How Ryegate compares
- In 8 years out of 10, the last spring frost in Ryegate falls between May 3 and May 30, a 27-day window. The first fall frost falls between September 10 and October 6.
- The median last frost is 2 days earlier than the Montana median of May 19.
- Its 129-day growing season is longer than 57% of the 325 Montana places with a regular frost season (state median 125 days).
- The last frost is 9 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 175 nights a year at or below 32°F.
- Compared with Billings, MT, 79 km away, the last frost here is 13 days later than there and the growing season is 27 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 3 |
| 50% (median) | May 17 |
| 10% (safe for tender plants) | May 30 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 10 |
| 50% (median) | September 23 |
| 90% (late) | October 6 |
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 Ryegate, MT
Ryegate, MT frost dates — last frost May 17, first frost Sep 23, zone 4b. whenisthelastfrost.com
Crop
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Start indoors: Feb 22 to Mar 8Transplant outside: Apr 19 to May 3
Start indoors: Mar 8 to Mar 22Transplant outside: May 31 to Jun 14
Start indoors: Mar 8 to Mar 22Transplant outside: May 31 to Jun 14
Start indoors: Mar 22 to Apr 5Transplant outside: May 24 to Jun 7
Start indoors: Mar 22 to Apr 5Transplant outside: Apr 26 to May 10Sow outdoors: Apr 19 to May 24Plant for fall: Jul 29 to Aug 26
Start indoors: Mar 22 to Apr 5Transplant outside: Apr 19 to May 3Sow outdoors: Apr 19 to May 3Plant for fall: Jul 15 to Aug 5
Start indoors: Mar 22 to Apr 5Transplant outside: May 3 to May 17Plant for fall: Jun 17 to Jul 8
Start indoors: Mar 22 to Apr 5Transplant outside: Apr 26 to May 10Plant for fall: Jun 17 to Jul 8
Start indoors: Mar 22 to Apr 5Transplant outside: May 3 to May 17Plant for fall: Jun 17 to Jul 8
Start indoors: Apr 5 to Apr 19Transplant outside: Jun 7 to Jun 21Sow outdoors: Jun 7 to Jun 21
Start indoors: Apr 5 to Apr 19Transplant outside: May 24 to Jun 7
Sow outdoors: Apr 5 to Apr 26Plant for fall: Jul 1 to Jul 22
Sow outdoors: Apr 5 to Apr 26Plant for fall: Jul 29 to Aug 19
Sow outdoors: Apr 12 to May 24Plant for fall: Aug 12 to Sep 2
Start indoors: Apr 19 to Apr 26Transplant outside: May 31 to Jun 7Sow outdoors: May 24 to Jun 7Plant for fall: Jul 8 to Jul 22
Start indoors: Apr 19 to Apr 26Sow outdoors: May 24 to Jun 7Plant for fall: Jul 15 to Jul 29
Start indoors: Apr 19 to Apr 26Sow outdoors: May 24 to Jun 7
Start indoors: Apr 19 to Apr 26Transplant outside: May 31 to Jun 14
Sow outdoors: Apr 26 to May 24Plant for fall: Jul 1 to Jul 15
Sow outdoors: Apr 26 to May 24Plant for fall: Jul 15 to Jul 29
Sow outdoors: Apr 26 to May 17
Sow outdoors: May 3 to May 31Plant for fall: Jul 15 to Jul 29
Sow outdoors: May 3 to May 24Plant for fall: Jul 29 to Aug 19
Sow outdoors: May 24 to Jun 14Plant for fall: Jul 8 to Jul 22
Sow outdoors: May 24 to Jun 7
Transplant outside: May 31 to Jun 21
Plant for fall: Sep 9 to Oct 14
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Ryegate, MT
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 22 – Mar 8 | Apr 19 – May 3 | — | — |
| Peppers | Mar 8 – Mar 22 | May 31 – Jun 14 | — | — |
| Eggplant | Mar 8 – Mar 22 | May 31 – Jun 14 | — | — |
| Tomatoes | Mar 22 – Apr 5 | May 24 – Jun 7 | — | — |
| Lettuce | Mar 22 – Apr 5 | Apr 26 – May 10 | Apr 19 – May 24 | Jul 29 – Aug 26 |
| Kale | Mar 22 – Apr 5 | Apr 19 – May 3 | Apr 19 – May 3 | Jul 15 – Aug 5 |
| Broccoli | Mar 22 – Apr 5 | May 3 – May 17 | — | Jun 17 – Jul 8 |
| Cabbage | Mar 22 – Apr 5 | Apr 26 – May 10 | — | Jun 17 – Jul 8 |
| Cauliflower | Mar 22 – Apr 5 | May 3 – May 17 | — | Jun 17 – Jul 8 |
| Okra | Apr 5 – Apr 19 | Jun 7 – Jun 21 | Jun 7 – Jun 21 | — |
| Basil | Apr 5 – Apr 19 | May 24 – Jun 7 | — | — |
| Peas | — | — | Apr 5 – Apr 26 | Jul 1 – Jul 22 |
| Spinach | — | — | Apr 5 – Apr 26 | Jul 29 – Aug 19 |
| Radishes | — | — | Apr 12 – May 24 | Aug 12 – Sep 2 |
| Cucumbers | Apr 19 – Apr 26 | May 31 – Jun 7 | May 24 – Jun 7 | Jul 8 – Jul 22 |
| Zucchini & Summer Squash | Apr 19 – Apr 26 | — | May 24 – Jun 7 | Jul 15 – Jul 29 |
| Winter Squash & Pumpkins | Apr 19 – Apr 26 | — | May 24 – Jun 7 | — |
| Melons & Watermelon | Apr 19 – Apr 26 | May 31 – Jun 14 | — | — |
| Carrots | — | — | Apr 26 – May 24 | Jul 1 – Jul 15 |
| Beets | — | — | Apr 26 – May 24 | Jul 15 – Jul 29 |
| Potatoes | — | — | Apr 26 – May 17 | — |
| Swiss Chard | — | — | May 3 – May 31 | Jul 15 – Jul 29 |
| Cilantro | — | — | May 3 – May 24 | Jul 29 – Aug 19 |
| Green Beans | — | — | May 24 – Jun 14 | Jul 8 – Jul 22 |
| Sweet Corn | — | — | May 24 – Jun 7 | — |
| Sweet Potatoes | — | May 31 – Jun 21 | — | — |
| Garlic | — | — | — | Sep 9 – Oct 14 |
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 Ryegate, MT weather station, 3 km away (elevation 3,652 ft (1,113 m)).
Frost dates near Ryegate
- Lavina May 22 · Sep 15
- Shawmut May 23 · Sep 16
- Rapelje May 24 · Sep 21
- Broadview May 22 · Sep 15
- Melville Jun 9 · Sep 7
- Harlowton May 23 · Sep 16
- Molt May 24 · Sep 21
- Judith Gap Jun 1 · Sep 15
- Roundup May 20 · Sep 21
- Acton May 4 · Oct 7
Frequently asked questions
When is the last frost in Ryegate, MT?
The median last spring frost in Ryegate, MT is May 17. There is still about a 10% chance of frost after May 30, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Ryegate, MT?
The median first fall frost is September 23, with about a 10% chance of frost before September 10.
How long is the growing season in Ryegate, MT?
About 129 days between the median last spring frost and first fall frost.
What planting zone is Ryegate, MT?
Ryegate, MT is in USDA hardiness zone 4b.