Saint Xavier, MT frost dates
Last spring frostMay 7median date
First fall frostOct 5median date
Growing season151 daysfrost-free
Hardiness zone5aZone 5a
How Saint Xavier compares
- In 8 years out of 10, the last spring frost in Saint Xavier falls between April 20 and May 24, a 34-day window. The first fall frost falls between September 20 and October 22.
- The median last frost is 12 days earlier than the Montana median of May 19.
- Its 151-day growing season is longer than 95% of the 325 Montana places with a regular frost season (state median 125 days).
- The last frost is 4 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 126 nights a year at or below 32°F.
- Compared with Billings, MT, 66 km away, the last frost here is 3 days later than there and the growing season is 5 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 20 |
| 50% (median) | May 7 |
| 10% (safe for tender plants) | May 24 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 20 |
| 50% (median) | October 5 |
| 90% (late) | October 22 |
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 Saint Xavier, MT
Saint Xavier, MT frost dates — last frost May 7, first frost Oct 5, zone 5a. whenisthelastfrost.com
Crop
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Start indoors: Feb 12 to Feb 26Transplant outside: Apr 9 to Apr 23
Start indoors: Feb 26 to Mar 12Transplant outside: May 21 to Jun 4
Start indoors: Feb 26 to Mar 12Transplant outside: May 21 to Jun 4
Start indoors: Mar 12 to Mar 26Transplant outside: May 14 to May 28
Start indoors: Mar 12 to Mar 26Transplant outside: Apr 16 to Apr 30Sow outdoors: Apr 9 to May 14Plant for fall: Aug 10 to Sep 7
Start indoors: Mar 12 to Mar 26Transplant outside: Apr 9 to Apr 23Sow outdoors: Apr 9 to Apr 23Plant for fall: Jul 27 to Aug 17
Start indoors: Mar 12 to Mar 26Transplant outside: Apr 23 to May 7Plant for fall: Jun 29 to Jul 20
Start indoors: Mar 12 to Mar 26Transplant outside: Apr 16 to Apr 30Plant for fall: Jun 29 to Jul 20
Start indoors: Mar 12 to Mar 26Transplant outside: Apr 23 to May 7Plant for fall: Jun 29 to Jul 20
Start indoors: Mar 26 to Apr 9Transplant outside: May 28 to Jun 11Sow outdoors: May 28 to Jun 11
Start indoors: Mar 26 to Apr 9Transplant outside: May 14 to May 28
Sow outdoors: Mar 26 to Apr 16Plant for fall: Jul 13 to Aug 3
Sow outdoors: Mar 26 to Apr 16Plant for fall: Aug 10 to Aug 31
Sow outdoors: Apr 2 to May 14Plant for fall: Aug 24 to Sep 14
Start indoors: Apr 9 to Apr 16Transplant outside: May 21 to May 28Sow outdoors: May 14 to May 28Plant for fall: Jul 20 to Aug 3
Start indoors: Apr 9 to Apr 16Sow outdoors: May 14 to May 28Plant for fall: Jul 27 to Aug 10
Start indoors: Apr 9 to Apr 16Sow outdoors: May 14 to May 28
Start indoors: Apr 9 to Apr 16Transplant outside: May 21 to Jun 4
Sow outdoors: Apr 16 to May 14Plant for fall: Jul 13 to Jul 27
Sow outdoors: Apr 16 to May 14Plant for fall: Jul 27 to Aug 10
Sow outdoors: Apr 16 to May 7
Sow outdoors: Apr 23 to May 21Plant for fall: Jul 27 to Aug 10
Sow outdoors: Apr 23 to May 14Plant for fall: Aug 10 to Aug 31
Sow outdoors: May 14 to Jun 4Plant for fall: Jul 20 to Aug 3
Sow outdoors: May 14 to May 28
Transplant outside: May 21 to Jun 11
Plant for fall: Sep 21 to Oct 26
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Saint Xavier, MT
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 12 – Feb 26 | Apr 9 – Apr 23 | — | — |
| Peppers | Feb 26 – Mar 12 | May 21 – Jun 4 | — | — |
| Eggplant | Feb 26 – Mar 12 | May 21 – Jun 4 | — | — |
| Tomatoes | Mar 12 – Mar 26 | May 14 – May 28 | — | — |
| Lettuce | Mar 12 – Mar 26 | Apr 16 – Apr 30 | Apr 9 – May 14 | Aug 10 – Sep 7 |
| Kale | Mar 12 – Mar 26 | Apr 9 – Apr 23 | Apr 9 – Apr 23 | Jul 27 – Aug 17 |
| Broccoli | Mar 12 – Mar 26 | Apr 23 – May 7 | — | Jun 29 – Jul 20 |
| Cabbage | Mar 12 – Mar 26 | Apr 16 – Apr 30 | — | Jun 29 – Jul 20 |
| Cauliflower | Mar 12 – Mar 26 | Apr 23 – May 7 | — | Jun 29 – Jul 20 |
| Okra | Mar 26 – Apr 9 | May 28 – Jun 11 | May 28 – Jun 11 | — |
| Basil | Mar 26 – Apr 9 | May 14 – May 28 | — | — |
| Peas | — | — | Mar 26 – Apr 16 | Jul 13 – Aug 3 |
| Spinach | — | — | Mar 26 – Apr 16 | Aug 10 – Aug 31 |
| Radishes | — | — | Apr 2 – May 14 | Aug 24 – Sep 14 |
| Cucumbers | Apr 9 – Apr 16 | May 21 – May 28 | May 14 – May 28 | Jul 20 – Aug 3 |
| Zucchini & Summer Squash | Apr 9 – Apr 16 | — | May 14 – May 28 | Jul 27 – Aug 10 |
| Winter Squash & Pumpkins | Apr 9 – Apr 16 | — | May 14 – May 28 | — |
| Melons & Watermelon | Apr 9 – Apr 16 | May 21 – Jun 4 | — | — |
| Carrots | — | — | Apr 16 – May 14 | Jul 13 – Jul 27 |
| Beets | — | — | Apr 16 – May 14 | Jul 27 – Aug 10 |
| Potatoes | — | — | Apr 16 – May 7 | — |
| Swiss Chard | — | — | Apr 23 – May 21 | Jul 27 – Aug 10 |
| Cilantro | — | — | Apr 23 – May 14 | Aug 10 – Aug 31 |
| Green Beans | — | — | May 14 – Jun 4 | Jul 20 – Aug 3 |
| Sweet Corn | — | — | May 14 – May 28 | — |
| Sweet Potatoes | — | May 21 – Jun 11 | — | — |
| Garlic | — | — | — | Sep 21 – Oct 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 Yellowtail Dam, MT weather station, 10 km away (elevation 3,304 ft (1,007 m)).
Frost dates near Saint Xavier
- Fort Smith May 7 · Oct 5
- Garryowen May 13 · Sep 29
- Crow Agency May 13 · Sep 29
- Lodge Grass May 21 · Sep 17
- Hardin May 13 · Sep 29
- Wyola May 21 · Sep 17
- Pryor May 14 · Sep 24
- Huntley May 12 · Sep 25
- Ballantine May 12 · Sep 25
- Pompeys Pillar May 22 · Sep 22
Frequently asked questions
When is the last frost in Saint Xavier, MT?
The median last spring frost in Saint Xavier, MT is May 7. There is still about a 10% chance of frost after May 24, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Saint Xavier, MT?
The median first fall frost is October 5, with about a 10% chance of frost before September 20.
How long is the growing season in Saint Xavier, MT?
About 151 days between the median last spring frost and first fall frost.
What planting zone is Saint Xavier, MT?
Saint Xavier, MT is in USDA hardiness zone 5a.