Bigfork, MT frost dates
Last spring frostMay 12median date
First fall frostSep 25median date
Growing season136 daysfrost-free
Hardiness zone5bZone 5b
How Bigfork compares
- In 8 years out of 10, the last spring frost in Bigfork falls between April 30 and May 26, a 26-day window. The first fall frost falls between September 9 and October 8.
- The median last frost is 7 days earlier than the Montana median of May 19.
- Its 136-day growing season is longer than 72% of the 325 Montana places with a regular frost season (state median 125 days).
- The last frost is 11 days later than the zone 5b median of May 1. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 5b chart.
- The weather station records an average of 179 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 30 |
| 50% (median) | May 12 |
| 10% (safe for tender plants) | May 26 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 9 |
| 50% (median) | September 25 |
| 90% (late) | October 8 |
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 Bigfork, MT
Bigfork, MT frost dates — last frost May 12, first frost Sep 25, zone 5b. whenisthelastfrost.com
Crop
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Start indoors: Feb 17 to Mar 3Transplant outside: Apr 14 to Apr 28
Start indoors: Mar 3 to Mar 17Transplant outside: May 26 to Jun 9
Start indoors: Mar 3 to Mar 17Transplant outside: May 26 to Jun 9
Start indoors: Mar 17 to Mar 31Transplant outside: May 19 to Jun 2
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 21 to May 5Sow outdoors: Apr 14 to May 19Plant for fall: Jul 31 to Aug 28
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 14 to Apr 28Sow outdoors: Apr 14 to Apr 28Plant for fall: Jul 17 to Aug 7
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 28 to May 12Plant for fall: Jun 19 to Jul 10
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 21 to May 5Plant for fall: Jun 19 to Jul 10
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 28 to May 12Plant for fall: Jun 19 to Jul 10
Start indoors: Mar 31 to Apr 14Transplant outside: Jun 2 to Jun 16Sow outdoors: Jun 2 to Jun 16
Start indoors: Mar 31 to Apr 14Transplant outside: May 19 to Jun 2
Sow outdoors: Mar 31 to Apr 21Plant for fall: Jul 3 to Jul 24
Sow outdoors: Mar 31 to Apr 21Plant for fall: Jul 31 to Aug 21
Sow outdoors: Apr 7 to May 19Plant for fall: Aug 14 to Sep 4
Start indoors: Apr 14 to Apr 21Transplant outside: May 26 to Jun 2Sow outdoors: May 19 to Jun 2Plant for fall: Jul 10 to Jul 24
Start indoors: Apr 14 to Apr 21Sow outdoors: May 19 to Jun 2Plant for fall: Jul 17 to Jul 31
Start indoors: Apr 14 to Apr 21Sow outdoors: May 19 to Jun 2
Start indoors: Apr 14 to Apr 21Transplant outside: May 26 to Jun 9
Sow outdoors: Apr 21 to May 19Plant for fall: Jul 3 to Jul 17
Sow outdoors: Apr 21 to May 19Plant for fall: Jul 17 to Jul 31
Sow outdoors: Apr 21 to May 12
Sow outdoors: Apr 28 to May 26Plant for fall: Jul 17 to Jul 31
Sow outdoors: Apr 28 to May 19Plant for fall: Jul 31 to Aug 21
Sow outdoors: May 19 to Jun 9Plant for fall: Jul 10 to Jul 24
Sow outdoors: May 19 to Jun 2
Transplant outside: May 26 to Jun 16
Plant for fall: Sep 11 to Oct 16
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Bigfork, MT
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 17 – Mar 3 | Apr 14 – Apr 28 | — | — |
| Peppers | Mar 3 – Mar 17 | May 26 – Jun 9 | — | — |
| Eggplant | Mar 3 – Mar 17 | May 26 – Jun 9 | — | — |
| Tomatoes | Mar 17 – Mar 31 | May 19 – Jun 2 | — | — |
| Lettuce | Mar 17 – Mar 31 | Apr 21 – May 5 | Apr 14 – May 19 | Jul 31 – Aug 28 |
| Kale | Mar 17 – Mar 31 | Apr 14 – Apr 28 | Apr 14 – Apr 28 | Jul 17 – Aug 7 |
| Broccoli | Mar 17 – Mar 31 | Apr 28 – May 12 | — | Jun 19 – Jul 10 |
| Cabbage | Mar 17 – Mar 31 | Apr 21 – May 5 | — | Jun 19 – Jul 10 |
| Cauliflower | Mar 17 – Mar 31 | Apr 28 – May 12 | — | Jun 19 – Jul 10 |
| Okra | Mar 31 – Apr 14 | Jun 2 – Jun 16 | Jun 2 – Jun 16 | — |
| Basil | Mar 31 – Apr 14 | May 19 – Jun 2 | — | — |
| Peas | — | — | Mar 31 – Apr 21 | Jul 3 – Jul 24 |
| Spinach | — | — | Mar 31 – Apr 21 | Jul 31 – Aug 21 |
| Radishes | — | — | Apr 7 – May 19 | Aug 14 – Sep 4 |
| Cucumbers | Apr 14 – Apr 21 | May 26 – Jun 2 | May 19 – Jun 2 | Jul 10 – Jul 24 |
| Zucchini & Summer Squash | Apr 14 – Apr 21 | — | May 19 – Jun 2 | Jul 17 – Jul 31 |
| Winter Squash & Pumpkins | Apr 14 – Apr 21 | — | May 19 – Jun 2 | — |
| Melons & Watermelon | Apr 14 – Apr 21 | May 26 – Jun 9 | — | — |
| Carrots | — | — | Apr 21 – May 19 | Jul 3 – Jul 17 |
| Beets | — | — | Apr 21 – May 19 | Jul 17 – Jul 31 |
| Potatoes | — | — | Apr 21 – May 12 | — |
| Swiss Chard | — | — | Apr 28 – May 26 | Jul 17 – Jul 31 |
| Cilantro | — | — | Apr 28 – May 19 | Jul 31 – Aug 21 |
| Green Beans | — | — | May 19 – Jun 9 | Jul 10 – Jul 24 |
| Sweet Corn | — | — | May 19 – Jun 2 | — |
| Sweet Potatoes | — | May 26 – Jun 16 | — | — |
| Garlic | — | — | — | Sep 11 – Oct 16 |
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 Creston, MT weather station, 15 km away (elevation 2,936 ft (895 m)).
Frost dates near Bigfork
- Somers May 12 · Sep 25
- Lakeside May 12 · Sep 25
- Rollins May 1 · Oct 15
- Kalispell May 31 · Sep 10
- Proctor May 1 · Oct 15
- Dayton May 1 · Oct 15
- Lake Mc Donald May 9 · Oct 1
- Kila May 12 · Sep 25
- Elmo May 15 · Sep 28
- Columbia Falls May 31 · Sep 10
Frequently asked questions
When is the last frost in Bigfork, MT?
The median last spring frost in Bigfork, MT is May 12. There is still about a 10% chance of frost after May 26, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Bigfork, MT?
The median first fall frost is September 25, with about a 10% chance of frost before September 9.
How long is the growing season in Bigfork, MT?
About 136 days between the median last spring frost and first fall frost.
What planting zone is Bigfork, MT?
Bigfork, MT is in USDA hardiness zone 5b.