Frost dates for 59219Dagmar, MT
The average last spring frost in Dagmar is May 16 and the average first fall frost is September 18, giving a typical growing season of about 125 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 16
- Average first fall frost
- Sep 18
- Growing season
- 125 days
Safer after May 30 (1-in-10 risk)
Possible by Sep 7 (1-in-10 risk)
Last frost typically in 201 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 16 · May 29 · Jun 23 | Aug 30 · Sep 10 · Sep 21 | 103 days | 100% |
| Frost / freeze (32°F) | May 4 · May 16 · May 30 | Sep 7 · Sep 18 · Sep 28 | 125 days | 100% |
| Hard freeze (28°F) | Apr 21 · May 5 · May 17 | Sep 13 · Sep 25 · Oct 6 | 141 days | 100% |
Planting calendar for Dagmar
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 15 – Jun 21 |
| Tomatoes | Transplant outdoors | Jun 1 – May 29 |
| Peppers | Start seeds indoors | Apr 15 – May 16 |
| Peppers | Transplant outdoors | Jun 15 – Jul 16 |
| Eggplant | Start seeds indoors | May 2 – May 31 |
| Eggplant | Transplant outdoors | Jun 15 – Jul 16 |
| Cucumbers | Sow outdoors | Jun 15 – Jun 8 |
| Summer squash | Sow outdoors | Jun 1 – Jul 16 |
| Winter squash & pumpkins | Sow outdoors | Jun 15 – Jul 16 |
| Snap beans | Sow outdoors | Jun 1 – Jul 1 |
| Sweet corn | Sow outdoors | Jun 1 – May 29 |
| Watermelon & cantaloupe | Sow outdoors | Jun 15 – Jul 16 |
| Okra | Sow outdoors | Jun 8 – Jul 1 |
| Peas | Sow outdoors (spring) | Apr 15 – May 31 |
| Potatoes | Plant outdoors (spring) | Apr 15 – Jun 15 |
| Onions | Start seeds indoors (spring) | Mar 4 – Mar 31 |
| Onions | Transplant outdoors (spring) | May 2 – May 31 |
| Broccoli | Start seeds indoors (spring) | Mar 28 – May 1 |
| Broccoli | Transplant outdoors (spring) | May 2 – May 31 |
| Broccoli | Start seeds indoors (fall) | May 19 – May 29 |
| Broccoli | Transplant outdoors (fall) | Jun 18 – Jun 29 |
| Cabbage | Start seeds indoors (spring) | Mar 18 – Apr 15 |
| Cabbage | Transplant outdoors (spring) | Apr 15 – May 16 |
| Cabbage | Start seeds indoors (fall) | May 9 – Jun 8 |
| Cabbage | Transplant outdoors (fall) | Jun 8 – Jul 9 |
| Leaf lettuce | Sow outdoors (spring) | Apr 15 – Jul 1 |
| Leaf lettuce | Sow outdoors (fall) | Jun 8 – Jul 25 |
| Spinach | Sow outdoors (spring) | Apr 8 – May 22 |
| Spinach | Sow outdoors (fall) | Jun 25 – Jul 30 |
| Radishes | Sow outdoors (spring) | Apr 15 – Jun 5 |
| Radishes | Sow outdoors (fall) | Jun 8 – Aug 9 |
| Kale | Sow outdoors (spring) | May 2 – May 22 |
| Kale | Sow outdoors (fall) | Jun 1 – Jul 9 |
| Carrots | Sow outdoors (spring) | May 16 – Jul 1 |
| Carrots | Sow outdoors (fall) | May 9 – Jun 24 |
| Garlic | Plant outdoors (fall) | Sep 8 – Oct 9 |
Where these dates come from
ZIP code 59219 is matched to the NOAA station Medicine Lake 3 Se, MT, 21 km away, at 1,942 ft elevation (138 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Medicine Lake 3 Se, MT (used) | 1,942 ft | May 16 | Sep 18 |
| Plentywood, MT | 2,048 ft | May 25 | Sep 14 |
| Westby, MT | 2,103 ft | May 18 | Sep 21 |
| Fortuna 1 W, ND | 2,350 ft | May 19 | Sep 17 |
Frost dates near Dagmar
- Antelope, MT 59211 · last May 25, first Sep 14
- Medicine Lake, MT 59247 · last May 16, first Sep 18
- Homestead, MT 59242 · last May 16, first Sep 18
- Grenora, ND 58845 · last May 18, first Sep 21
- Reserve, MT 59258 · last May 25, first Sep 14
- Westby, MT 59275 · last May 18, first Sep 21
- Plentywood, MT 59254 · last May 25, first Sep 14
- Froid, MT 59226 · last May 16, first Sep 18
Frequently asked questions
- When is the last frost in Dagmar, MT?
- For ZIP code 59219, the average last spring frost (32°F) is May 16, based on NOAA 1991-2020 climate normals for the Medicine Lake 3 Se, MT weather station. There is a 1-in-10 chance of a frost after May 30.
- When is the first frost in Dagmar, MT?
- The average first fall frost (32°F) is September 18. There is a 1-in-10 chance of frost by September 7, so tender plants are at risk from that point on.
- How long is the growing season in 59219?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 125 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.