Frost dates for 82633Douglas, WY
The average last spring frost in Douglas is May 19 and the average first fall frost is September 23, giving a typical growing season of about 126 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 19
- Average first fall frost
- Sep 23
- Growing season
- 126 days
Safer after Jun 2 (1-in-10 risk)
Possible by Sep 10 (1-in-10 risk)
Last frost typically in 198 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 19 · Jun 1 · Jun 15 | Aug 31 · Sep 13 · Sep 27 | 104 days | 100% |
| Frost / freeze (32°F) | May 7 · May 19 · Jun 2 | Sep 10 · Sep 23 · Oct 6 | 126 days | 100% |
| Hard freeze (28°F) | Apr 24 · May 7 · May 21 | Sep 18 · Oct 3 · Oct 16 | 147 days | 100% |
Planting calendar for Douglas
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 18 – Jun 24 |
| Tomatoes | Transplant outdoors | Jun 4 – Jun 3 |
| Peppers | Start seeds indoors | Apr 18 – May 19 |
| Peppers | Transplant outdoors | Jun 18 – Jul 19 |
| Eggplant | Start seeds indoors | May 5 – Jun 3 |
| Eggplant | Transplant outdoors | Jun 18 – Jul 19 |
| Cucumbers | Sow outdoors | Jun 18 – Jun 13 |
| Summer squash | Sow outdoors | Jun 4 – Jul 19 |
| Winter squash & pumpkins | Sow outdoors | Jun 18 – Jul 19 |
| Snap beans | Sow outdoors | Jun 4 – Jul 6 |
| Sweet corn | Sow outdoors | Jun 4 – Jun 3 |
| Watermelon & cantaloupe | Sow outdoors | Jun 18 – Jul 19 |
| Okra | Sow outdoors | Jun 11 – Jul 4 |
| Peas | Sow outdoors (spring) | Apr 18 – Jun 3 |
| Potatoes | Plant outdoors (spring) | Apr 18 – Jun 18 |
| Onions | Start seeds indoors (spring) | Mar 7 – Apr 3 |
| Onions | Transplant outdoors (spring) | May 5 – Jun 3 |
| Broccoli | Start seeds indoors (spring) | Mar 31 – May 4 |
| Broccoli | Transplant outdoors (spring) | May 5 – Jun 3 |
| Broccoli | Start seeds indoors (fall) | May 24 – Jun 3 |
| Broccoli | Transplant outdoors (fall) | Jun 23 – Jul 4 |
| Cabbage | Start seeds indoors (spring) | Mar 21 – Apr 18 |
| Cabbage | Transplant outdoors (spring) | Apr 18 – May 19 |
| Cabbage | Start seeds indoors (fall) | May 14 – Jun 13 |
| Cabbage | Transplant outdoors (fall) | Jun 13 – Jul 14 |
| Leaf lettuce | Sow outdoors (spring) | Apr 18 – Jul 4 |
| Leaf lettuce | Sow outdoors (fall) | Jun 13 – Jul 30 |
| Spinach | Sow outdoors (spring) | Apr 11 – May 25 |
| Spinach | Sow outdoors (fall) | Jun 30 – Aug 4 |
| Radishes | Sow outdoors (spring) | Apr 18 – Jun 8 |
| Radishes | Sow outdoors (fall) | Jun 13 – Aug 14 |
| Kale | Sow outdoors (spring) | May 5 – May 25 |
| Kale | Sow outdoors (fall) | Jun 6 – Jul 14 |
| Carrots | Sow outdoors (spring) | May 19 – Jul 4 |
| Carrots | Sow outdoors (fall) | May 14 – Jun 29 |
| Garlic | Plant outdoors (fall) | Sep 13 – Oct 14 |
Where these dates come from
ZIP code 82633 is matched to the NOAA station Douglas 1 Se, WY, 2.7 km away, at 4,870 ft elevation (51 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Douglas 1 Se, WY (used) | 4,870 ft | May 19 | Sep 23 |
| Douglas Converse Co Ap, WY | 4,929 ft | May 23 | Sep 22 |
| Glendo 6Ne, WY | 4,739 ft | May 25 | Sep 15 |
| Glendo Rsvr Usbr, WY | 4,780 ft | May 9 | Oct 5 |
Frost dates near Douglas
- Shawnee, WY 82229 · last May 23, first Sep 22
- Glenrock, WY 82637 · last May 10, first Sep 29
- Glendo, WY 82213 · last May 9, first Oct 5
- Manville, WY 82227 · last May 23, first Sep 20
- Lost Springs, WY 82224 · last May 15, first Sep 27
- Evansville, WY 82636 · last May 10, first Sep 29
- Garrett, WY 82058 · last —, first —
- Lance Creek, WY 82222 · last May 17, first Sep 25
Frequently asked questions
- When is the last frost in Douglas, WY?
- For ZIP code 82633, the average last spring frost (32°F) is May 19, based on NOAA 1991-2020 climate normals for the Douglas 1 Se, WY weather station. There is a 1-in-10 chance of a frost after June 2.
- When is the first frost in Douglas, WY?
- The average first fall frost (32°F) is September 23. There is a 1-in-10 chance of frost by September 10, so tender plants are at risk from that point on.
- How long is the growing season in 82633?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 126 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.