Frost dates for Lyman, WY
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 14
typical year
Safe to plant
July 1
frost is over in 9 of 10 years
First fall frost
September 9
typical year
Growing season
84 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 17 – 31 | – |
| Spinach | – | May 3 – 24 | Jul 15 – 29 |
| Lettuce | – | May 17 – Jun 7 | Jul 15 – 29 |
| Radishes | – | May 17 – Jun 28 | Jul 29 – Aug 12 |
| Onions | – | May 17 – 31 | – |
| Potatoes | Season usually too short. Try a quick variety or row covers. | ||
| Carrots | – | May 24 – Jun 14 | Jun 17 – Jul 1 |
| Beets | – | May 17 – 31 | Jul 1 – 15 |
| Kale | Apr 5 – 19 | May 17 – 31 | Jul 1 – 15 |
| Broccoli | Apr 5 – 19 | May 31 – Jun 14 | Jul 1 – 15 |
| Cabbage | Mar 22 – Apr 5 | May 17 – 31 | Jul 1 – 15 |
| Garlic | – | – | Jul 29 – Aug 19 |
| 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 1 – 22 | – |
| Zucchini | – | Jul 1 – 29 | – |
| Pumpkins | Season usually too short. Try a quick variety or row covers. | ||
| Green beans | – | Jul 1 | – |
| Sweet corn | Season usually too short. Try a quick variety or row covers. | ||
| Basil | May 27 – Jun 10 | Jul 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 | July 1 | June 14 | May 31 |
| Fall frost before | August 23 | September 9 | September 21 |
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 30 (June 17 in a late year), and the first one in fall around September 20.
Towns that use these dates
This is the nearest NOAA station with frost records for 2 towns.
Lyman, Mountain View
Where these dates come from
NOAA weather station MTN VIEW, WY US (USC00486555), 1991–2020 climate normals. It's the nearest station for 6 zip codes, all within 25 miles:
82930, 82933, 82936, 82937, 82939, 82944
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.