Frost dates for Libby, 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 11
typical year
Safe to plant
May 27
frost is over in 9 of 10 years
First fall frost
October 1
typical year
Growing season
142 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 13 – 27 | – |
| Spinach | – | Mar 30 – Apr 20 | Aug 6 – 20 |
| Lettuce | – | Apr 13 – May 4 | Aug 6 – 20 |
| Radishes | – | Apr 13 – May 25 | Aug 20 – Sep 3 |
| Onions | – | Apr 13 – 27 | – |
| Potatoes | – | Apr 20 – May 4 | – |
| Carrots | – | Apr 20 – May 11 | Jul 9 – 23 |
| Beets | – | Apr 13 – 27 | Jul 23 – Aug 6 |
| Kale | Mar 2 – 16 | Apr 13 – 27 | Jul 23 – Aug 6 |
| Broccoli | Mar 2 – 16 | Apr 27 – May 11 | Jul 23 – Aug 6 |
| Cabbage | Feb 16 – Mar 2 | Apr 13 – 27 | Jul 23 – Aug 6 |
| Garlic | – | – | Aug 20 – Sep 10 |
| Warm-season crops | |||
| Tomatoes | Apr 1 – 15 | May 27 – Jun 10 | – |
| Peppers | Mar 25 – Apr 8 | Jun 3 – 17 | – |
| Cucumbers | – | May 27 – Jun 17 | – |
| Zucchini | – | May 27 – Jun 24 | – |
| Pumpkins | – | May 27 – Jun 17 | – |
| Green beans | – | May 27 – Jul 23 | – |
| Sweet corn | – | May 27 – Jun 24 | – |
| Basil | Apr 22 – May 6 | Jun 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 | May 27 | May 11 | April 30 |
| Fall frost before | September 14 | October 1 | October 18 |
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 28 (May 11 in a late year), and the first one in fall around October 16.
Towns that use these dates
This is the nearest NOAA station with frost records for 1 town.
Libby
Where these dates come from
NOAA weather station LIBBY DAM (BASE), MT US (USC00245011), 1991–2020 climate normals. It's the nearest station for 1 zip code, all within 10 miles:
59923
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.