Frost dates for Denton, 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 1
typical year
Safe to plant
June 26
frost is over in 9 of 10 years
First fall frost
September 11
typical year
Growing season
101 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 4 – 18 | – |
| Spinach | – | Apr 20 – May 11 | Jul 17 – 31 |
| Lettuce | – | May 4 – 25 | Jul 17 – 31 |
| Radishes | – | May 4 – Jun 15 | Jul 31 – Aug 14 |
| Onions | – | May 4 – 18 | – |
| Potatoes | Season usually too short. Try a quick variety or row covers. | ||
| Carrots | – | May 11 – Jun 1 | Jun 19 – Jul 3 |
| Beets | – | May 4 – 18 | Jul 3 – 17 |
| Kale | Mar 23 – Apr 6 | May 4 – 18 | Jul 3 – 17 |
| Broccoli | Mar 23 – Apr 6 | May 18 – Jun 1 | Jul 3 – 17 |
| Cabbage | Mar 9 – 23 | May 4 – 18 | Jul 3 – 17 |
| Garlic | – | – | Jul 31 – Aug 21 |
| Warm-season crops | |||
| Tomatoes | May 1 – 15 | Jun 26 – Jul 10 | – |
| Peppers | Season usually too short. Try a quick variety or row covers. | ||
| Cucumbers | – | Jun 26 – Jul 17 | – |
| Zucchini | – | Jun 26 – Jul 24 | – |
| Pumpkins | Season usually too short. Try a quick variety or row covers. | ||
| Green beans | – | Jun 26 – Jul 3 | – |
| Sweet corn | Season usually too short. Try a quick variety or row covers. | ||
| Basil | May 22 – Jun 5 | Jul 3 – 10 | – |
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 26 | June 1 | May 15 |
| Fall frost before | August 29 | September 11 | September 25 |
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 14 (May 31 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.
Denton
Where these dates come from
NOAA weather station DENTON, MT US (USC00242347), 1991–2020 climate normals. It's the nearest station for 2 zip codes, all within 11 miles:
59424, 59430
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.