Frost dates for Alberton, 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
May 18
typical year
Safe to plant
June 6
frost is over in 9 of 10 years
First fall frost
September 25
typical year
Growing season
126 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 | – | Apr 20 – May 4 | – |
| Spinach | – | Apr 6 – 27 | Jul 31 – Aug 14 |
| Lettuce | – | Apr 20 – May 11 | Jul 31 – Aug 14 |
| Radishes | – | Apr 20 – Jun 1 | Aug 14 – 28 |
| Onions | – | Apr 20 – May 4 | – |
| Potatoes | – | Apr 27 – May 11 | – |
| Carrots | – | Apr 27 – May 18 | Jul 3 – 17 |
| Beets | – | Apr 20 – May 4 | Jul 17 – 31 |
| Kale | Mar 9 – 23 | Apr 20 – May 4 | Jul 17 – 31 |
| Broccoli | Mar 9 – 23 | May 4 – 18 | Jul 17 – 31 |
| Cabbage | Feb 23 – Mar 9 | Apr 20 – May 4 | Jul 17 – 31 |
| Garlic | – | – | Aug 14 – Sep 4 |
| Warm-season crops | |||
| Tomatoes | Apr 11 – 25 | Jun 6 – 20 | – |
| Peppers | Apr 4 – 18 | Jun 13 – 27 | – |
| Cucumbers | – | Jun 6 – 27 | – |
| Zucchini | – | Jun 6 – Jul 4 | – |
| Pumpkins | – | Jun 6 – 27 | – |
| Green beans | – | Jun 6 – Jul 17 | – |
| Sweet corn | – | Jun 6 – Jul 4 | – |
| Basil | May 2 – 16 | Jun 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 | June 6 | May 18 | May 5 |
| Fall frost before | September 7 | September 25 | October 6 |
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 3 (May 15 in a late year), and the first one in fall around October 5.
Towns that use these dates
This is the nearest NOAA station with frost records for 1 town.
Alberton
Where these dates come from
NOAA weather station ALBERTON, MT US (USC00240075), 1991–2020 climate normals. It's the nearest station for 2 zip codes, all within 10 miles:
59820, 59846
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.