Frost dates for Fairfield, 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 13
typical year
Safe to plant
June 1
frost is over in 9 of 10 years
First fall frost
September 27
typical year
Growing season
135 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 15 – 29 | – |
| Spinach | – | Apr 1 – 22 | Aug 2 – 16 |
| Lettuce | – | Apr 15 – May 6 | Aug 2 – 16 |
| Radishes | – | Apr 15 – May 27 | Aug 16 – 30 |
| Onions | – | Apr 15 – 29 | – |
| Potatoes | – | Apr 22 – May 6 | – |
| Carrots | – | Apr 22 – May 13 | Jul 5 – 19 |
| Beets | – | Apr 15 – 29 | Jul 19 – Aug 2 |
| Kale | Mar 4 – 18 | Apr 15 – 29 | Jul 19 – Aug 2 |
| Broccoli | Mar 4 – 18 | Apr 29 – May 13 | Jul 19 – Aug 2 |
| Cabbage | Feb 18 – Mar 4 | Apr 15 – 29 | Jul 19 – Aug 2 |
| Garlic | – | – | Aug 16 – Sep 6 |
| Warm-season crops | |||
| Tomatoes | Apr 6 – 20 | Jun 1 – 15 | – |
| Peppers | Mar 30 – Apr 13 | Jun 8 – 22 | – |
| Cucumbers | – | Jun 1 – 22 | – |
| Zucchini | – | Jun 1 – 29 | – |
| Pumpkins | – | Jun 1 – 22 | – |
| Green beans | – | Jun 1 – Jul 19 | – |
| Sweet corn | – | Jun 1 – 29 | – |
| Basil | Apr 27 – May 11 | Jun 8 – 15 | – |
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 1 | May 13 | April 28 |
| Fall frost before | September 14 | September 27 | October 9 |
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 April 30 (May 14 in a late year), and the first one in fall around October 7.
Towns that use these dates
This is the nearest NOAA station with frost records for 1 town.
Fairfield
Where these dates come from
NOAA weather station FAIRFIELD, MT US (USC00242857), 1991–2020 climate normals. It's the nearest station for 1 zip code, all within 6 miles:
59436
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.