Frost dates for 82434Otto, WY
The average last spring frost in Otto is May 12 and the average first fall frost is September 28, giving a typical growing season of about 136 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 12
- Average first fall frost
- Sep 28
- Growing season
- 136 days
Safer after May 27 (1-in-10 risk)
Possible by Sep 14 (1-in-10 risk)
Last frost typically in 193 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 24 · Jun 11 | Sep 2 · Sep 17 · Sep 29 | 112 days | 100% |
| Frost / freeze (32°F) | Apr 30 · May 12 · May 27 | Sep 14 · Sep 28 · Oct 10 | 136 days | 100% |
| Hard freeze (28°F) | Apr 17 · May 1 · May 15 | Sep 23 · Oct 7 · Oct 20 | 158 days | 100% |
Planting calendar for Otto
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 11 – Jun 17 |
| Tomatoes | Transplant outdoors | May 28 – Jun 8 |
| Peppers | Start seeds indoors | Apr 11 – May 12 |
| Peppers | Transplant outdoors | Jun 11 – Jul 12 |
| Eggplant | Start seeds indoors | Apr 28 – May 27 |
| Eggplant | Transplant outdoors | Jun 11 – Jul 12 |
| Cucumbers | Sow outdoors | Jun 11 – Jun 18 |
| Summer squash | Sow outdoors | May 28 – Jul 12 |
| Winter squash & pumpkins | Sow outdoors | Jun 11 – Jul 12 |
| Snap beans | Sow outdoors | May 28 – Jul 11 |
| Sweet corn | Sow outdoors | May 28 – Jun 8 |
| Watermelon & cantaloupe | Sow outdoors | Jun 11 – Jul 12 |
| Okra | Sow outdoors | Jun 4 – Jun 27 |
| Peas | Sow outdoors (spring) | Apr 11 – May 27 |
| Potatoes | Plant outdoors (spring) | Apr 11 – Jun 11 |
| Onions | Start seeds indoors (spring) | Feb 28 – Mar 27 |
| Onions | Transplant outdoors (spring) | Apr 28 – May 27 |
| Broccoli | Start seeds indoors (spring) | Mar 24 – Apr 27 |
| Broccoli | Transplant outdoors (spring) | Apr 28 – May 27 |
| Broccoli | Start seeds indoors (fall) | May 29 – Jun 8 |
| Broccoli | Transplant outdoors (fall) | Jun 28 – Jul 9 |
| Cabbage | Start seeds indoors (spring) | Mar 14 – Apr 11 |
| Cabbage | Transplant outdoors (spring) | Apr 11 – May 12 |
| Cabbage | Start seeds indoors (fall) | May 19 – Jun 18 |
| Cabbage | Transplant outdoors (fall) | Jun 18 – Jul 19 |
| Leaf lettuce | Sow outdoors (spring) | Apr 11 – Jun 27 |
| Leaf lettuce | Sow outdoors (fall) | Jun 18 – Aug 4 |
| Spinach | Sow outdoors (spring) | Apr 4 – May 18 |
| Spinach | Sow outdoors (fall) | Jul 5 – Aug 9 |
| Radishes | Sow outdoors (spring) | Apr 11 – Jun 1 |
| Radishes | Sow outdoors (fall) | Jun 18 – Aug 19 |
| Kale | Sow outdoors (spring) | Apr 28 – May 18 |
| Kale | Sow outdoors (fall) | Jun 11 – Jul 19 |
| Carrots | Sow outdoors (spring) | May 12 – Jun 27 |
| Carrots | Sow outdoors (fall) | May 19 – Jul 4 |
| Garlic | Plant outdoors (fall) | Sep 18 – Oct 19 |
Where these dates come from
ZIP code 82434 is matched to the NOAA station Emblem, WY, 12.3 km away, at 4,448 ft elevation (249 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Emblem, WY (used) | 4,448 ft | May 12 | Sep 28 |
| Greybull S Big Horn Ap, WY | 3,933 ft | May 4 | Oct 1 |
| Basin, WY | 3,840 ft | Apr 28 | Oct 10 |
| Greybull, WY | 3,787 ft | May 11 | Sep 23 |
Frost dates near Otto
- Burlington, WY 82411 · last May 12, first Sep 28
- Emblem, WY 82422 · last May 12, first Sep 28
- Greybull, WY 82426 · last May 4, first Oct 1
- Basin, WY 82410 · last Apr 28, first Oct 10
- Manderson, WY 82432 · last Apr 28, first Oct 10
- Byron, WY 82412 · last May 6, first Oct 1
- Shell, WY 82441 · last May 16, first Sep 24
- Lovell, WY 82431 · last May 9, first Sep 29
Frequently asked questions
- When is the last frost in Otto, WY?
- For ZIP code 82434, the average last spring frost (32°F) is May 12, based on NOAA 1991-2020 climate normals for the Emblem, WY weather station. There is a 1-in-10 chance of a frost after May 27.
- When is the first frost in Otto, WY?
- The average first fall frost (32°F) is September 28. There is a 1-in-10 chance of frost by September 14, so tender plants are at risk from that point on.
- How long is the growing season in 82434?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 136 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.