Frost dates for 59257Redstone, MT
The average last spring frost in Redstone is May 28 and the average first fall frost is September 7, giving a typical growing season of about 101 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 28
- Average first fall frost
- Sep 7
- Growing season
- 101 days
Safer after Jun 13 (1-in-10 risk)
Possible by Aug 22 (1-in-10 risk)
Last frost typically in 206 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) | — | — | 72 days | 100% |
| Frost / freeze (32°F) | May 15 · May 28 · Jun 13 | Aug 22 · Sep 7 · Sep 19 | 101 days | 100% |
| Hard freeze (28°F) | May 4 · May 18 · May 31 | Sep 4 · Sep 16 · Sep 28 | 120 days | 100% |
Planting calendar for Redstone
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 27 – Jul 3 |
| Tomatoes | Transplant outdoors | Jun 13 – May 18 |
| Peppers | Start seeds indoors | Apr 27 – May 28 |
| Peppers | Transplant outdoors | Jun 27 – Jul 28 |
| Eggplant | Start seeds indoors | May 14 – Jun 12 |
| Eggplant | Transplant outdoors | Jun 27 – Jul 28 |
| Cucumbers | Sow outdoors | Jun 27 – May 28 |
| Summer squash | Sow outdoors | Jun 13 – Jul 28 |
| Winter squash & pumpkins | Sow outdoors | Jun 27 – Jul 28 |
| Snap beans | Sow outdoors | Jun 13 – Jun 20 |
| Sweet corn | Sow outdoors | Jun 13 – May 18 |
| Watermelon & cantaloupe | Sow outdoors | Jun 27 – Jul 28 |
| Okra | Sow outdoors | Jun 20 – Jul 13 |
| Peas | Sow outdoors (spring) | Apr 27 – Jun 12 |
| Potatoes | Plant outdoors (spring) | Apr 27 – Jun 27 |
| Onions | Start seeds indoors (spring) | Mar 16 – Apr 12 |
| Onions | Transplant outdoors (spring) | May 14 – Jun 12 |
| Broccoli | Start seeds indoors (spring) | Apr 9 – May 13 |
| Broccoli | Transplant outdoors (spring) | May 14 – Jun 12 |
| Broccoli | Start seeds indoors (fall) | May 8 – May 18 |
| Broccoli | Transplant outdoors (fall) | Jun 7 – Jun 18 |
| Cabbage | Start seeds indoors (spring) | Mar 30 – Apr 27 |
| Cabbage | Transplant outdoors (spring) | Apr 27 – May 28 |
| Cabbage | Start seeds indoors (fall) | Apr 28 – May 28 |
| Cabbage | Transplant outdoors (fall) | May 28 – Jun 28 |
| Leaf lettuce | Sow outdoors (spring) | Apr 27 – Jul 13 |
| Leaf lettuce | Sow outdoors (fall) | May 28 – Jul 14 |
| Spinach | Sow outdoors (spring) | Apr 20 – Jun 3 |
| Spinach | Sow outdoors (fall) | Jun 14 – Jul 19 |
| Radishes | Sow outdoors (spring) | Apr 27 – Jun 17 |
| Radishes | Sow outdoors (fall) | May 28 – Jul 29 |
| Kale | Sow outdoors (spring) | May 14 – Jun 3 |
| Kale | Sow outdoors (fall) | May 21 – Jun 28 |
| Carrots | Sow outdoors (spring) | May 28 – Jul 13 |
| Carrots | Sow outdoors (fall) | Apr 28 – Jun 13 |
| Garlic | Plant outdoors (fall) | Aug 28 – Sep 28 |
Where these dates come from
ZIP code 59257 is matched to the NOAA station Redstone, MT, 10.2 km away, at 2,106 ft elevation (358 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Redstone, MT (used) | 2,106 ft | May 28 | Sep 7 |
| Plentywood, MT | 2,048 ft | May 25 | Sep 14 |
| Wolf Point 34 Ne, MT | 2,643 ft | May 13 | Sep 28 |
| Bredette, MT | 2,313 ft | May 20 | Sep 21 |
Frost dates near Redstone
- Flaxville, MT 59222 · last May 13, first Sep 28
- Outlook, MT 59252 · last May 19, first Sep 23
- Whitetail, MT 59276 · last May 28, first Sep 6
- Reserve, MT 59258 · last May 25, first Sep 14
- Plentywood, MT 59254 · last May 25, first Sep 14
- Raymond, MT 59256 · last May 19, first Sep 23
- Scobey, MT 59263 · last May 28, first Sep 6
- Antelope, MT 59211 · last May 25, first Sep 14
Frequently asked questions
- When is the last frost in Redstone, MT?
- For ZIP code 59257, the average last spring frost (32°F) is May 28, based on NOAA 1991-2020 climate normals for the Redstone, MT weather station. There is a 1-in-10 chance of a frost after June 13.
- When is the first frost in Redstone, MT?
- The average first fall frost (32°F) is September 7. There is a 1-in-10 chance of frost by August 22, so tender plants are at risk from that point on.
- How long is the growing season in 59257?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 101 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.