Frost dates for 59312Angela, MT
The average last spring frost in Angela is May 15 and the average first fall frost is September 25, giving a typical growing season of about 132 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 15
- Average first fall frost
- Sep 25
- Growing season
- 132 days
Safer after May 27 (1-in-10 risk)
Possible by Sep 10 (1-in-10 risk)
Last frost typically in 200 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 10 | Aug 30 · Sep 16 · Sep 29 | 111 days | 100% |
| Frost / freeze (32°F) | May 2 · May 15 · May 27 | Sep 10 · Sep 25 · Oct 6 | 132 days | 100% |
| Hard freeze (28°F) | Apr 20 · May 5 · May 19 | Sep 21 · Oct 3 · Oct 17 | 152 days | 100% |
Planting calendar for Angela
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 14 – Jun 20 |
| Tomatoes | Transplant outdoors | May 31 – Jun 5 |
| Peppers | Start seeds indoors | Apr 14 – May 15 |
| Peppers | Transplant outdoors | Jun 14 – Jul 15 |
| Eggplant | Start seeds indoors | May 1 – May 30 |
| Eggplant | Transplant outdoors | Jun 14 – Jul 15 |
| Cucumbers | Sow outdoors | Jun 14 – Jun 15 |
| Summer squash | Sow outdoors | May 31 – Jul 15 |
| Winter squash & pumpkins | Sow outdoors | Jun 14 – Jul 15 |
| Snap beans | Sow outdoors | May 31 – Jul 8 |
| Sweet corn | Sow outdoors | May 31 – Jun 5 |
| Watermelon & cantaloupe | Sow outdoors | Jun 14 – Jul 15 |
| Okra | Sow outdoors | Jun 7 – Jun 30 |
| Peas | Sow outdoors (spring) | Apr 14 – May 30 |
| Potatoes | Plant outdoors (spring) | Apr 14 – Jun 14 |
| Onions | Start seeds indoors (spring) | Mar 3 – Mar 30 |
| Onions | Transplant outdoors (spring) | May 1 – May 30 |
| Broccoli | Start seeds indoors (spring) | Mar 27 – Apr 30 |
| Broccoli | Transplant outdoors (spring) | May 1 – May 30 |
| Broccoli | Start seeds indoors (fall) | May 26 – Jun 5 |
| Broccoli | Transplant outdoors (fall) | Jun 25 – Jul 6 |
| Cabbage | Start seeds indoors (spring) | Mar 17 – Apr 14 |
| Cabbage | Transplant outdoors (spring) | Apr 14 – May 15 |
| Cabbage | Start seeds indoors (fall) | May 16 – Jun 15 |
| Cabbage | Transplant outdoors (fall) | Jun 15 – Jul 16 |
| Leaf lettuce | Sow outdoors (spring) | Apr 14 – Jun 30 |
| Leaf lettuce | Sow outdoors (fall) | Jun 15 – Aug 1 |
| Spinach | Sow outdoors (spring) | Apr 7 – May 21 |
| Spinach | Sow outdoors (fall) | Jul 2 – Aug 6 |
| Radishes | Sow outdoors (spring) | Apr 14 – Jun 4 |
| Radishes | Sow outdoors (fall) | Jun 15 – Aug 16 |
| Kale | Sow outdoors (spring) | May 1 – May 21 |
| Kale | Sow outdoors (fall) | Jun 8 – Jul 16 |
| Carrots | Sow outdoors (spring) | May 15 – Jun 30 |
| Carrots | Sow outdoors (fall) | May 16 – Jul 1 |
| Garlic | Plant outdoors (fall) | Sep 15 – Oct 16 |
Where these dates come from
ZIP code 59312 is matched to the NOAA station Rock Springs, MT, 10.6 km away, at 3,024 ft elevation (101 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Rock Springs, MT (used) | 3,024 ft | May 15 | Sep 25 |
| Miles City F Wiley Fld, MT | 2,624 ft | May 8 | Sep 30 |
| Cohagen, MT | 2,720 ft | May 25 | Sep 14 |
| Forsyth, MT | 2,515 ft | May 9 | Sep 29 |
Frost dates near Angela
- Rosebud, MT 59347 · last May 9, first Sep 29
- Kinsey, MT 59338 · last May 8, first Sep 30
- Miles City, MT 59301 · last May 8, first Sep 30
- Cohagen, MT 59322 · last May 25, first Sep 14
- Hathaway, MT 59333 · last May 8, first Sep 30
- Forsyth, MT 59327 · last May 9, first Sep 29
- Terry, MT 59349 · last May 12, first Sep 28
- Brockway, MT 59214 · last May 20, first Sep 19
Frequently asked questions
- When is the last frost in Angela, MT?
- For ZIP code 59312, the average last spring frost (32°F) is May 15, based on NOAA 1991-2020 climate normals for the Rock Springs, MT weather station. There is a 1-in-10 chance of a frost after May 27.
- When is the first frost in Angela, MT?
- The average first fall frost (32°F) is September 25. 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 59312?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 132 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.