Vandalia, MT frost dates
Last spring frostMay 15median date
First fall frostSep 26median date
Growing season134 daysfrost-free
Hardiness zone4aZone 4a
How Vandalia compares
- In 8 years out of 10, the last spring frost in Vandalia falls between May 3 and May 30, a 27-day window. The first fall frost falls between September 12 and October 10.
- The median last frost is 4 days earlier than the Montana median of May 19.
- Its 134-day growing season is longer than 68% of the 325 Montana places with a regular frost season (state median 125 days).
- The last frost is typical for zone 4a, where the median is May 12.
- The weather station records an average of 177 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 3 |
| 50% (median) | May 15 |
| 10% (safe for tender plants) | May 30 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 12 |
| 50% (median) | September 26 |
| 90% (late) | October 10 |
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 Vandalia, MT
Vandalia, MT frost dates — last frost May 15, first frost Sep 26, zone 4a. whenisthelastfrost.com
Crop
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Start indoors: Feb 20 to Mar 6Transplant outside: Apr 17 to May 1
Start indoors: Mar 6 to Mar 20Transplant outside: May 29 to Jun 12
Start indoors: Mar 6 to Mar 20Transplant outside: May 29 to Jun 12
Start indoors: Mar 20 to Apr 3Transplant outside: May 22 to Jun 5
Start indoors: Mar 20 to Apr 3Transplant outside: Apr 24 to May 8Sow outdoors: Apr 17 to May 22Plant for fall: Aug 1 to Aug 29
Start indoors: Mar 20 to Apr 3Transplant outside: Apr 17 to May 1Sow outdoors: Apr 17 to May 1Plant for fall: Jul 18 to Aug 8
Start indoors: Mar 20 to Apr 3Transplant outside: May 1 to May 15Plant for fall: Jun 20 to Jul 11
Start indoors: Mar 20 to Apr 3Transplant outside: Apr 24 to May 8Plant for fall: Jun 20 to Jul 11
Start indoors: Mar 20 to Apr 3Transplant outside: May 1 to May 15Plant for fall: Jun 20 to Jul 11
Start indoors: Apr 3 to Apr 17Transplant outside: Jun 5 to Jun 19Sow outdoors: Jun 5 to Jun 19
Start indoors: Apr 3 to Apr 17Transplant outside: May 22 to Jun 5
Sow outdoors: Apr 3 to Apr 24Plant for fall: Jul 4 to Jul 25
Sow outdoors: Apr 3 to Apr 24Plant for fall: Aug 1 to Aug 22
Sow outdoors: Apr 10 to May 22Plant for fall: Aug 15 to Sep 5
Start indoors: Apr 17 to Apr 24Transplant outside: May 29 to Jun 5Sow outdoors: May 22 to Jun 5Plant for fall: Jul 11 to Jul 25
Start indoors: Apr 17 to Apr 24Sow outdoors: May 22 to Jun 5Plant for fall: Jul 18 to Aug 1
Start indoors: Apr 17 to Apr 24Sow outdoors: May 22 to Jun 5
Start indoors: Apr 17 to Apr 24Transplant outside: May 29 to Jun 12
Sow outdoors: Apr 24 to May 22Plant for fall: Jul 4 to Jul 18
Sow outdoors: Apr 24 to May 22Plant for fall: Jul 18 to Aug 1
Sow outdoors: Apr 24 to May 15
Sow outdoors: May 1 to May 29Plant for fall: Jul 18 to Aug 1
Sow outdoors: May 1 to May 22Plant for fall: Aug 1 to Aug 22
Sow outdoors: May 22 to Jun 12Plant for fall: Jul 11 to Jul 25
Sow outdoors: May 22 to Jun 5
Transplant outside: May 29 to Jun 19
Plant for fall: Sep 12 to Oct 17
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Vandalia, MT
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 20 – Mar 6 | Apr 17 – May 1 | — | — |
| Peppers | Mar 6 – Mar 20 | May 29 – Jun 12 | — | — |
| Eggplant | Mar 6 – Mar 20 | May 29 – Jun 12 | — | — |
| Tomatoes | Mar 20 – Apr 3 | May 22 – Jun 5 | — | — |
| Lettuce | Mar 20 – Apr 3 | Apr 24 – May 8 | Apr 17 – May 22 | Aug 1 – Aug 29 |
| Kale | Mar 20 – Apr 3 | Apr 17 – May 1 | Apr 17 – May 1 | Jul 18 – Aug 8 |
| Broccoli | Mar 20 – Apr 3 | May 1 – May 15 | — | Jun 20 – Jul 11 |
| Cabbage | Mar 20 – Apr 3 | Apr 24 – May 8 | — | Jun 20 – Jul 11 |
| Cauliflower | Mar 20 – Apr 3 | May 1 – May 15 | — | Jun 20 – Jul 11 |
| Okra | Apr 3 – Apr 17 | Jun 5 – Jun 19 | Jun 5 – Jun 19 | — |
| Basil | Apr 3 – Apr 17 | May 22 – Jun 5 | — | — |
| Peas | — | — | Apr 3 – Apr 24 | Jul 4 – Jul 25 |
| Spinach | — | — | Apr 3 – Apr 24 | Aug 1 – Aug 22 |
| Radishes | — | — | Apr 10 – May 22 | Aug 15 – Sep 5 |
| Cucumbers | Apr 17 – Apr 24 | May 29 – Jun 5 | May 22 – Jun 5 | Jul 11 – Jul 25 |
| Zucchini & Summer Squash | Apr 17 – Apr 24 | — | May 22 – Jun 5 | Jul 18 – Aug 1 |
| Winter Squash & Pumpkins | Apr 17 – Apr 24 | — | May 22 – Jun 5 | — |
| Melons & Watermelon | Apr 17 – Apr 24 | May 29 – Jun 12 | — | — |
| Carrots | — | — | Apr 24 – May 22 | Jul 4 – Jul 18 |
| Beets | — | — | Apr 24 – May 22 | Jul 18 – Aug 1 |
| Potatoes | — | — | Apr 24 – May 15 | — |
| Swiss Chard | — | — | May 1 – May 29 | Jul 18 – Aug 1 |
| Cilantro | — | — | May 1 – May 22 | Aug 1 – Aug 22 |
| Green Beans | — | — | May 22 – Jun 12 | Jul 11 – Jul 25 |
| Sweet Corn | — | — | May 22 – Jun 5 | — |
| Sweet Potatoes | — | May 29 – Jun 19 | — | — |
| Garlic | — | — | — | Sep 12 – Oct 17 |
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 Hinsdale 4 Sw, MT weather station, 18 km away (elevation 2,805 ft (855 m)).
Frost dates near Vandalia
- Hinsdale May 15 · Sep 26
- Saint Marie May 13 · Sep 27
- Glasgow May 6 · Sep 30
- Nashua May 12 · Sep 24
- Saco May 15 · Sep 23
- Fort Peck May 8 · Oct 1
- Larslan Jun 5 · Sep 2
- Frazer May 12 · Sep 24
- Richland Jun 5 · Sep 2
- Malta May 10 · Sep 29
Frequently asked questions
When is the last frost in Vandalia, MT?
The median last spring frost in Vandalia, MT is May 15. 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 Vandalia, MT?
The median first fall frost is September 26, with about a 10% chance of frost before September 12.
How long is the growing season in Vandalia, MT?
About 134 days between the median last spring frost and first fall frost.
What planting zone is Vandalia, MT?
Vandalia, MT is in USDA hardiness zone 4a.