Lima, MT frost dates
Last spring frostJun 11median date
First fall frostSep 10median date
Growing season91 daysfrost-free
Hardiness zone5aZone 5a
How Lima compares
- In 8 years out of 10, the last spring frost in Lima falls between May 24 and June 30, a 37-day window. The first fall frost falls between August 27 and September 24.
- The median last frost is 23 days later than the Montana median of May 19.
- Its 91-day growing season is longer than 6% of the 325 Montana places with a regular frost season (state median 125 days).
- The last frost is 39 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 226 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 24 |
| 50% (median) | June 11 |
| 10% (safe for tender plants) | June 30 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | August 27 |
| 50% (median) | September 10 |
| 90% (late) | September 24 |
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 Lima, MT
Lima, MT frost dates — last frost Jun 11, first frost Sep 10, zone 5a. whenisthelastfrost.com
Crop
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Start indoors: Mar 19 to Apr 2Transplant outside: May 14 to May 28
Start indoors: Apr 2 to Apr 16Transplant outside: Jun 25 to Jul 9
Start indoors: Apr 2 to Apr 16Transplant outside: Jun 25 to Jul 9
Start indoors: Apr 16 to Apr 30Transplant outside: Jun 18 to Jul 2
Start indoors: Apr 16 to Apr 30Transplant outside: May 21 to Jun 4Sow outdoors: May 14 to Jun 18Plant for fall: Jul 16 to Aug 13
Start indoors: Apr 16 to Apr 30Transplant outside: May 14 to May 28Sow outdoors: May 14 to May 28Plant for fall: Jul 2 to Jul 23
Start indoors: Apr 16 to Apr 30Transplant outside: May 28 to Jun 11
Start indoors: Apr 16 to Apr 30Transplant outside: May 21 to Jun 4
Start indoors: Apr 16 to Apr 30Transplant outside: May 28 to Jun 11
Start indoors: Apr 30 to May 14Transplant outside: Jul 2 to Jul 16Sow outdoors: Jul 2 to Jul 16
Start indoors: Apr 30 to May 14Transplant outside: Jun 18 to Jul 2
Sow outdoors: Apr 30 to May 21
Sow outdoors: Apr 30 to May 21Plant for fall: Jul 16 to Aug 6
Sow outdoors: May 7 to Jun 18Plant for fall: Jul 30 to Aug 20
Start indoors: May 14 to May 21Transplant outside: Jun 25 to Jul 2Sow outdoors: Jun 18 to Jul 2
Start indoors: May 14 to May 21Sow outdoors: Jun 18 to Jul 2
Start indoors: May 14 to May 21Sow outdoors: Jun 18 to Jul 2
Start indoors: May 14 to May 21Transplant outside: Jun 25 to Jul 9
Sow outdoors: May 21 to Jun 18
Sow outdoors: May 21 to Jun 18
Sow outdoors: May 21 to Jun 11
Sow outdoors: May 28 to Jun 25
Sow outdoors: May 28 to Jun 18Plant for fall: Jul 16 to Aug 6
Sow outdoors: Jun 18 to Jul 9
Sow outdoors: Jun 18 to Jul 2
Transplant outside: Jun 25 to Jul 16
Plant for fall: Aug 27 to Oct 1
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Lima, MT
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Mar 19 – Apr 2 | May 14 – May 28 | — | — |
| Peppers | Apr 2 – Apr 16 | Jun 25 – Jul 9 | — | — |
| Eggplant | Apr 2 – Apr 16 | Jun 25 – Jul 9 | — | — |
| Tomatoes | Apr 16 – Apr 30 | Jun 18 – Jul 2 | — | — |
| Lettuce | Apr 16 – Apr 30 | May 21 – Jun 4 | May 14 – Jun 18 | Jul 16 – Aug 13 |
| Kale | Apr 16 – Apr 30 | May 14 – May 28 | May 14 – May 28 | Jul 2 – Jul 23 |
| Broccoli | Apr 16 – Apr 30 | May 28 – Jun 11 | — | — |
| Cabbage | Apr 16 – Apr 30 | May 21 – Jun 4 | — | — |
| Cauliflower | Apr 16 – Apr 30 | May 28 – Jun 11 | — | — |
| Okra | Apr 30 – May 14 | Jul 2 – Jul 16 | Jul 2 – Jul 16 | — |
| Basil | Apr 30 – May 14 | Jun 18 – Jul 2 | — | — |
| Peas | — | — | Apr 30 – May 21 | — |
| Spinach | — | — | Apr 30 – May 21 | Jul 16 – Aug 6 |
| Radishes | — | — | May 7 – Jun 18 | Jul 30 – Aug 20 |
| Cucumbers | May 14 – May 21 | Jun 25 – Jul 2 | Jun 18 – Jul 2 | — |
| Zucchini & Summer Squash | May 14 – May 21 | — | Jun 18 – Jul 2 | — |
| Winter Squash & Pumpkins Warning: Your frost-free season is about 91 days, which is tight for winter squash & pumpkins (100+ days). Choose early varieties and use transplants or row covers. | May 14 – May 21 | — | Jun 18 – Jul 2 | — |
| Melons & Watermelon Warning: Your frost-free season is about 91 days, which is tight for melons & watermelon (85+ days). Choose early varieties and use transplants or row covers. | May 14 – May 21 | Jun 25 – Jul 9 | — | — |
| Carrots | — | — | May 21 – Jun 18 | — |
| Beets | — | — | May 21 – Jun 18 | — |
| Potatoes | — | — | May 21 – Jun 11 | — |
| Swiss Chard | — | — | May 28 – Jun 25 | — |
| Cilantro | — | — | May 28 – Jun 18 | Jul 16 – Aug 6 |
| Green Beans | — | — | Jun 18 – Jul 9 | — |
| Sweet Corn Warning: Your frost-free season is about 91 days, which is tight for sweet corn (80+ days). Choose early varieties and use transplants or row covers. | — | — | Jun 18 – Jul 2 | — |
| Sweet Potatoes Warning: Your frost-free season is about 91 days, which is tight for sweet potatoes (100+ days). Choose early varieties and use transplants or row covers. | — | Jun 25 – Jul 16 | — | — |
| Garlic | — | — | — | Aug 27 – Oct 1 |
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 Lima, MT weather station, 3 km away (elevation 6,280 ft (1,914 m)).
Frost dates near Lima
- Dell Jun 11 · Sep 10
- Dillon Jun 5 · Sep 13
- Alder frost any month
- Virginia City Jun 4 · Sep 18
- Cameron Jun 16 · Sep 4
- Polaris frost any month
- Sheridan May 24 · Sep 22
- Glen frost any month
- Twin Bridges Jun 8 · Sep 2
- Jackson frost any month
Frequently asked questions
When is the last frost in Lima, MT?
The median last spring frost in Lima, MT is June 11. There is still about a 10% chance of frost after June 30, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Lima, MT?
The median first fall frost is September 10, with about a 10% chance of frost before August 27.
How long is the growing season in Lima, MT?
About 91 days between the median last spring frost and first fall frost.
What planting zone is Lima, MT?
Lima, MT is in USDA hardiness zone 5a.