Frost dates for Lima, MT
When the last spring frost and first fall frost usually come, and when to plant, from 30 years of NOAA weather records.
Last spring frost
June 11
typical year
Safe to plant
June 30
frost is over in 9 of 10 years
First fall frost
September 10
typical year
Growing season
89 days
frost-free, typical year
Frost watch this week
Tonight's and the next six nights' lows from the National Weather Service forecast for the station's location. Frost: 32°F or colder. Possible frost: 33–36°F, mostly in low spots on clear, still nights.
When to plant
Counted from this page's frost dates. Warm-season crops wait for the safe-to-plant date.
| Crop | Start indoors | Plant outside | Fall planting |
|---|---|---|---|
| Cool-season crops | |||
| Peas | – | May 14 – 28 | – |
| Spinach | – | Apr 30 – May 21 | Jul 16 – 30 |
| Lettuce | – | May 14 – Jun 4 | Jul 16 – 30 |
| Radishes | – | May 14 – Jun 25 | Jul 30 – Aug 13 |
| Onions | – | May 14 – 28 | – |
| Potatoes | Season usually too short. Try a quick variety or row covers. | ||
| Carrots | – | May 21 – Jun 11 | Jun 18 – Jul 2 |
| Beets | – | May 14 – 28 | Jul 2 – 16 |
| Kale | Apr 2 – 16 | May 14 – 28 | Jul 2 – 16 |
| Broccoli | Apr 2 – 16 | May 28 – Jun 11 | Jul 2 – 16 |
| Cabbage | Mar 19 – Apr 2 | May 14 – 28 | Jul 2 – 16 |
| Garlic | – | – | Jul 30 – Aug 20 |
| Warm-season crops | |||
| Tomatoes | Season usually too short. Try a quick variety or row covers. | ||
| Peppers | Season usually too short. Try a quick variety or row covers. | ||
| Cucumbers | – | Jun 30 – Jul 21 | – |
| Zucchini | – | Jun 30 – Jul 28 | – |
| Pumpkins | Season usually too short. Try a quick variety or row covers. | ||
| Green beans | – | Jun 30 – Jul 2 | – |
| Sweet corn | Season usually too short. Try a quick variety or row covers. | ||
| Basil | May 26 – Jun 9 | Jul 7 – 14 | – |
Onions: from sets. Green beans: until 10 weeks before the first fall frost. Garlic: harvest next summer.
The year at a glance
Start indoors Plant outside Fall planting
The chance of frost, by date
| 1 year in 10 | Half of years | 9 years in 10 | |
|---|---|---|---|
| Spring frost after | June 30 | June 11 | May 24 |
| Fall frost before | August 27 | September 10 | September 24 |
Frost here means 32°F or colder. Read across: in 1 year in 10, spring frost carries on past the first date, which is why that date is the safe-to-plant date.
Hard freeze (28°F)
A hard freeze kills most garden plants, even hardy ones. The last one in spring usually comes around May 21 (June 13 in a late year), and the first one in fall around September 23.
Towns that use these dates
This is the nearest NOAA station with frost records for 1 town.
Lima
Where these dates come from
NOAA weather station LIMA, MT US (USC00245030), 1991–2020 climate normals. It's the nearest station for 3 zip codes, all within 32 miles:
59724, 59739, 83464
1 of these zip codes are more than 30 miles from the station, so their real frost dates may differ by a week or more.
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.