Frost dates for 82329Medicine Bow, WY
The average last spring frost in Medicine Bow is June 1 and the average first fall frost is September 8, giving a typical growing season of about 97 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Jun 1
- Average first fall frost
- Sep 8
- Growing season
- 97 days
Safer after Jun 19 (1-in-10 risk)
Possible by Aug 28 (1-in-10 risk)
Last frost typically in 217 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) | — | — | 69 days | 100% |
| Frost / freeze (32°F) | May 20 · Jun 1 · Jun 19 | Aug 28 · Sep 8 · Sep 20 | 97 days | 100% |
| Hard freeze (28°F) | May 8 · May 19 · Jun 1 | Sep 5 · Sep 17 · Oct 1 | 120 days | 100% |
Planting calendar for Medicine Bow
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 | May 1 – Jul 7 |
| Tomatoes | Transplant outdoors | Jun 17 – May 19 |
| Peppers | Start seeds indoors | May 1 – Jun 1 |
| Peppers | Transplant outdoors | Jul 1 – Aug 1 |
| Eggplant | Start seeds indoors | May 18 – Jun 16 |
| Eggplant | Transplant outdoors | Jul 1 – Aug 1 |
| Cucumbers | Sow outdoors | Jul 1 – May 29 |
| Summer squash | Sow outdoors | Jun 17 – Aug 1 |
| Winter squash & pumpkins | Sow outdoors | Jul 1 – Aug 1 |
| Snap beans | Sow outdoors | Jun 17 – Jun 21 |
| Sweet corn | Sow outdoors | Jun 17 – May 19 |
| Watermelon & cantaloupe | Sow outdoors | Jul 1 – Aug 1 |
| Okra | Sow outdoors | Jun 24 – Jul 17 |
| Peas | Sow outdoors (spring) | May 1 – Jun 16 |
| Potatoes | Plant outdoors (spring) | May 1 – Jul 1 |
| Onions | Start seeds indoors (spring) | Mar 20 – Apr 16 |
| Onions | Transplant outdoors (spring) | May 18 – Jun 16 |
| Broccoli | Start seeds indoors (spring) | Apr 13 – May 17 |
| Broccoli | Transplant outdoors (spring) | May 18 – Jun 16 |
| Broccoli | Start seeds indoors (fall) | May 9 – May 19 |
| Broccoli | Transplant outdoors (fall) | Jun 8 – Jun 19 |
| Cabbage | Start seeds indoors (spring) | Apr 3 – May 1 |
| Cabbage | Transplant outdoors (spring) | May 1 – Jun 1 |
| Cabbage | Start seeds indoors (fall) | Apr 29 – May 29 |
| Cabbage | Transplant outdoors (fall) | May 29 – Jun 29 |
| Leaf lettuce | Sow outdoors (spring) | May 1 – Jul 17 |
| Leaf lettuce | Sow outdoors (fall) | May 29 – Jul 15 |
| Spinach | Sow outdoors (spring) | Apr 24 – Jun 7 |
| Spinach | Sow outdoors (fall) | Jun 15 – Jul 20 |
| Radishes | Sow outdoors (spring) | May 1 – Jun 21 |
| Radishes | Sow outdoors (fall) | May 29 – Jul 30 |
| Kale | Sow outdoors (spring) | May 18 – Jun 7 |
| Kale | Sow outdoors (fall) | May 22 – Jun 29 |
| Carrots | Sow outdoors (spring) | Jun 1 – Jul 17 |
| Carrots | Sow outdoors (fall) | Apr 29 – Jun 14 |
| Garlic | Plant outdoors (fall) | Aug 29 – Sep 29 |
Where these dates come from
ZIP code 82329 is matched to the NOAA station Medicine Bow, WY, 0.8 km away, at 6,635 ft elevation (80 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Medicine Bow, WY (used) | 6,635 ft | Jun 1 | Sep 8 |
| Elk Mtn, WY | 7,265 ft | May 28 | Sep 13 |
| Shirley Basin, WY | 7,057 ft | — | — |
| Leo 6 Sw, WY | 6,035 ft | May 20 | Sep 28 |
Frost dates near Medicine Bow
- Rock River, WY 82083 · last Jun 1, first Sep 8
- Hanna, WY 82327 · last Jun 1, first Sep 8
- Elk Mountain, WY 82324 · last May 28, first Sep 13
- Garrett, WY 82058 · last —, first —
- Walcott, WY 82335 · last Jun 1, first Sep 15
- Bosler, WY 82051 · last Jun 7, first Sep 4
- Laramie, WY 82070 · last Jun 7, first Sep 4
- Saratoga, WY 82331 · last Jun 12, first Sep 7
Frequently asked questions
- When is the last frost in Medicine Bow, WY?
- For ZIP code 82329, the average last spring frost (32°F) is June 1, based on NOAA 1991-2020 climate normals for the Medicine Bow, WY weather station. There is a 1-in-10 chance of a frost after June 19.
- When is the first frost in Medicine Bow, WY?
- The average first fall frost (32°F) is September 8. There is a 1-in-10 chance of frost by August 28, so tender plants are at risk from that point on.
- How long is the growing season in 82329?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 97 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.