Frost dates for Ennis, 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 16
typical year
Safe to plant
July 6
frost is over in 9 of 10 years
First fall frost
September 4
typical year
Growing season
78 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 19 – Jun 2 | – |
| Spinach | – | May 5 – 26 | Jul 10 – 24 |
| Lettuce | – | May 19 – Jun 9 | Jul 10 – 24 |
| Radishes | – | May 19 – Jun 30 | Jul 24 – Aug 7 |
| Onions | – | May 19 – Jun 2 | – |
| Potatoes | Season usually too short. Try a quick variety or row covers. | ||
| Carrots | – | May 26 – Jun 16 | Jun 12 – 26 |
| Beets | – | May 19 – Jun 2 | Jun 26 – Jul 10 |
| Kale | Apr 7 – 21 | May 19 – Jun 2 | Jun 26 – Jul 10 |
| Broccoli | Apr 7 – 21 | Jun 2 – 16 | Jun 26 – Jul 10 |
| Cabbage | Mar 24 – Apr 7 | May 19 – Jun 2 | Jun 26 – Jul 10 |
| Garlic | – | – | Jul 24 – Aug 14 |
| 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 | – | Jul 6 – 27 | – |
| Zucchini | – | Jul 6 – Aug 3 | – |
| Pumpkins | Season usually too short. Try a quick variety or row covers. | ||
| Green beans | Season usually too short. Try a quick variety or row covers. | ||
| Sweet corn | Season usually too short. Try a quick variety or row covers. | ||
| Basil | Jun 1 – 15 | Jul 13 – 20 | – |
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 | July 6 | June 16 | May 30 |
| Fall frost before | August 20 | September 4 | September 19 |
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 23 (June 12 in a late year), and the first one in fall around September 18.
Towns that use these dates
This is the nearest NOAA station with frost records for 1 town.
Ennis
Where these dates come from
NOAA weather station ENNIS, MT US (USC00242793), 1991–2020 climate normals. It's the nearest station for 2 zip codes, all within 16 miles:
59716, 59729
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.