Frost dates for 82642Lysite, WY
The average last spring frost in Lysite is May 14 and the average first fall frost is October 3, giving a typical growing season of about 140 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 14
- Average first fall frost
- Oct 3
- Growing season
- 140 days
Safer after Jun 1 (1-in-10 risk)
Possible by Sep 20 (1-in-10 risk)
Last frost typically in 199 days
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | May 11 · May 27 · Jun 11 | Sep 10 · Sep 25 · Oct 9 | 120 days | 100% |
| Frost / freeze (32°F) | Apr 29 · May 14 · Jun 1 | Sep 20 · Oct 3 · Oct 18 | 140 days | 100% |
| Hard freeze (28°F) | Apr 15 · May 1 · May 19 | Sep 28 · Oct 12 · Oct 28 | 162 days | 100% |
Planting calendar for Lysite
Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | Apr 13 – Jun 19 |
| Tomatoes | Transplant outdoors | May 30 – Jun 13 |
| Peppers | Start seeds indoors | Apr 13 – May 14 |
| Peppers | Transplant outdoors | Jun 13 – Jul 14 |
| Eggplant | Start seeds indoors | Apr 30 – May 29 |
| Eggplant | Transplant outdoors | Jun 13 – Jul 14 |
| Cucumbers | Sow outdoors | Jun 13 – Jun 23 |
| Summer squash | Sow outdoors | May 30 – Jul 14 |
| Winter squash & pumpkins | Sow outdoors | Jun 13 – Jul 14 |
| Snap beans | Sow outdoors | May 30 – Jul 16 |
| Sweet corn | Sow outdoors | May 30 – Jun 13 |
| Watermelon & cantaloupe | Sow outdoors | Jun 13 – Jul 14 |
| Okra | Sow outdoors | Jun 6 – Jun 29 |
| Peas | Sow outdoors (spring) | Apr 13 – May 29 |
| Potatoes | Plant outdoors (spring) | Apr 13 – Jun 13 |
| Onions | Start seeds indoors (spring) | Mar 2 – Mar 29 |
| Onions | Transplant outdoors (spring) | Apr 30 – May 29 |
| Broccoli | Start seeds indoors (spring) | Mar 26 – Apr 29 |
| Broccoli | Transplant outdoors (spring) | Apr 30 – May 29 |
| Broccoli | Start seeds indoors (fall) | Jun 3 – Jun 13 |
| Broccoli | Transplant outdoors (fall) | Jul 3 – Jul 14 |
| Cabbage | Start seeds indoors (spring) | Mar 16 – Apr 13 |
| Cabbage | Transplant outdoors (spring) | Apr 13 – May 14 |
| Cabbage | Start seeds indoors (fall) | May 24 – Jun 23 |
| Cabbage | Transplant outdoors (fall) | Jun 23 – Jul 24 |
| Leaf lettuce | Sow outdoors (spring) | Apr 13 – Jun 29 |
| Leaf lettuce | Sow outdoors (fall) | Jun 23 – Aug 9 |
| Spinach | Sow outdoors (spring) | Apr 6 – May 20 |
| Spinach | Sow outdoors (fall) | Jul 10 – Aug 14 |
| Radishes | Sow outdoors (spring) | Apr 13 – Jun 3 |
| Radishes | Sow outdoors (fall) | Jun 23 – Aug 24 |
| Kale | Sow outdoors (spring) | Apr 30 – May 20 |
| Kale | Sow outdoors (fall) | Jun 16 – Jul 24 |
| Carrots | Sow outdoors (spring) | May 14 – Jun 29 |
| Carrots | Sow outdoors (fall) | May 24 – Jul 9 |
| Garlic | Plant outdoors (fall) | Sep 23 – Oct 24 |
Where these dates come from
ZIP code 82642 is matched to the NOAA station Black Mtn, WY, 37.1 km away, at 5,635 ft elevation (162 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Black Mtn, WY (used) | 5,635 ft | May 14 | Oct 3 |
| Shoshoni, WY | 4,837 ft | May 7 | Oct 3 |
| Boysen Dam, WY | 4,875 ft | May 5 | Oct 7 |
| Thermopolis, WY | 4,321 ft | May 5 | Oct 5 |
Frost dates near Lysite
- Hiland, WY 82638 · last May 30, first Sep 22
- Arminto, WY 82630 · last May 30, first Sep 22
- Shoshoni, WY 82649 · last May 7, first Oct 3
- Riverton, WY 82501 · last May 12, first Sep 24
- Powder River, WY 82648 · last May 30, first Sep 22
- Kirby, WY 82430 · last May 5, first Oct 5
- Saint Stephens, WY 82524 · last May 12, first Sep 24
- Natrona, WY 82646 · last May 23, first Sep 20
Frequently asked questions
- When is the last frost in Lysite, WY?
- For ZIP code 82642, the average last spring frost (32°F) is May 14, based on NOAA 1991-2020 climate normals for the Black Mtn, WY weather station. There is a 1-in-10 chance of a frost after June 1.
- When is the first frost in Lysite, WY?
- The average first fall frost (32°F) is October 3. There is a 1-in-10 chance of frost by September 20, so tender plants are at risk from that point on.
- How long is the growing season in 82642?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 140 days long.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.