Frost dates for 82002Cheyenne, WY
The average last spring frost in Cheyenne is May 14 and the average first fall frost is October 1, giving a typical growing season of about 139 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 14
- Average first fall frost
- Oct 1
- Growing season
- 139 days
Safer after May 28 (1-in-10 risk)
Possible by Sep 17 (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 13 · May 26 · Jun 7 | Sep 11 · Sep 24 · Oct 5 | 120 days | 100% |
| Frost / freeze (32°F) | May 3 · May 14 · May 28 | Sep 17 · Oct 1 · Oct 14 | 139 days | 100% |
| Hard freeze (28°F) | Apr 20 · May 3 · May 17 | Sep 27 · Oct 10 · Oct 23 | 157 days | 100% |
Planting calendar for Cheyenne
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 11 |
| 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 21 |
| Summer squash | Sow outdoors | May 30 – Jul 14 |
| Winter squash & pumpkins | Sow outdoors | Jun 13 – Jul 14 |
| Snap beans | Sow outdoors | May 30 – Jul 14 |
| Sweet corn | Sow outdoors | May 30 – Jun 11 |
| 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 1 – Jun 11 |
| Broccoli | Transplant outdoors (fall) | Jul 1 – Jul 12 |
| Cabbage | Start seeds indoors (spring) | Mar 16 – Apr 13 |
| Cabbage | Transplant outdoors (spring) | Apr 13 – May 14 |
| Cabbage | Start seeds indoors (fall) | May 22 – Jun 21 |
| Cabbage | Transplant outdoors (fall) | Jun 21 – Jul 22 |
| Leaf lettuce | Sow outdoors (spring) | Apr 13 – Jun 29 |
| Leaf lettuce | Sow outdoors (fall) | Jun 21 – Aug 7 |
| Spinach | Sow outdoors (spring) | Apr 6 – May 20 |
| Spinach | Sow outdoors (fall) | Jul 8 – Aug 12 |
| Radishes | Sow outdoors (spring) | Apr 13 – Jun 3 |
| Radishes | Sow outdoors (fall) | Jun 21 – Aug 22 |
| Kale | Sow outdoors (spring) | Apr 30 – May 20 |
| Kale | Sow outdoors (fall) | Jun 14 – Jul 22 |
| Carrots | Sow outdoors (spring) | May 14 – Jun 29 |
| Carrots | Sow outdoors (fall) | May 22 – Jul 7 |
| Garlic | Plant outdoors (fall) | Sep 21 – Oct 22 |
Where these dates come from
ZIP code 82002 is matched to the NOAA station Cheyenne Wfo, WY, 1.8 km away, at 6,119 ft elevation (27 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Cheyenne Wfo, WY (used) | 6,119 ft | May 14 | Oct 1 |
| Cheyenne, WY | 6,128 ft | May 12 | Oct 1 |
| Archer, WY | 6,010 ft | May 21 | Sep 24 |
| Hecla 1E, WY | 6,690 ft | May 27 | Sep 19 |
Frost dates near Cheyenne
- Cheyenne, WY 82006 · last May 14, first Oct 1
- Fe Warren Afb, WY 82005 · last May 12, first Oct 1
- Hillsdale, WY 82060 · last May 14, first Sep 26
- Granite Canon, WY 82059 · last May 31, first Sep 19
- Carr, CO 80612 · last May 13, first Sep 27
- Buford, WY 82052 · last May 31, first Sep 19
- Horse Creek, WY 82061 · last May 27, first Sep 19
- Burns, WY 82053 · last May 16, first Sep 27
Frequently asked questions
- When is the last frost in Cheyenne, WY?
- For ZIP code 82002, the average last spring frost (32°F) is May 14, based on NOAA 1991-2020 climate normals for the Cheyenne Wfo, WY weather station. There is a 1-in-10 chance of a frost after May 28.
- When is the first frost in Cheyenne, WY?
- The average first fall frost (32°F) is October 1. There is a 1-in-10 chance of frost by September 17, so tender plants are at risk from that point on.
- How long is the growing season in 82002?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 139 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.