Frost dates for 59330Glendive, MT
The average last spring frost in Glendive is May 3 and the average first fall frost is October 4, giving a typical growing season of about 153 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 3
- Average first fall frost
- Oct 4
- Growing season
- 153 days
Safer after May 16 (1-in-10 risk)
Possible by Sep 22 (1-in-10 risk)
Last frost typically in 188 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 2 · May 14 · May 27 | Sep 12 · Sep 26 · Oct 7 | 134 days | 100% |
| Frost / freeze (32°F) | Apr 19 · May 3 · May 16 | Sep 22 · Oct 4 · Oct 17 | 153 days | 100% |
| Hard freeze (28°F) | Apr 9 · Apr 24 · May 8 | Sep 30 · Oct 13 · Oct 27 | 172 days | 100% |
Planting calendar for Glendive
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 2 – Jun 8 |
| Tomatoes | Transplant outdoors | May 19 – Jun 14 |
| Peppers | Start seeds indoors | Apr 2 – May 3 |
| Peppers | Transplant outdoors | Jun 2 – Jul 3 |
| Eggplant | Start seeds indoors | Apr 19 – May 18 |
| Eggplant | Transplant outdoors | Jun 2 – Jul 3 |
| Cucumbers | Sow outdoors | Jun 2 – Jun 24 |
| Summer squash | Sow outdoors | May 19 – Jul 3 |
| Winter squash & pumpkins | Sow outdoors | Jun 2 – Jul 3 |
| Snap beans | Sow outdoors | May 19 – Jul 17 |
| Sweet corn | Sow outdoors | May 19 – Jun 14 |
| Watermelon & cantaloupe | Sow outdoors | Jun 2 – Jul 3 |
| Okra | Sow outdoors | May 26 – Jun 18 |
| Peas | Sow outdoors (spring) | Apr 2 – May 18 |
| Potatoes | Plant outdoors (spring) | Apr 2 – Jun 2 |
| Onions | Start seeds indoors (spring) | Feb 19 – Mar 18 |
| Onions | Transplant outdoors (spring) | Apr 19 – May 18 |
| Broccoli | Start seeds indoors (spring) | Mar 15 – Apr 18 |
| Broccoli | Transplant outdoors (spring) | Apr 19 – May 18 |
| Broccoli | Start seeds indoors (fall) | Jun 4 – Jun 14 |
| Broccoli | Transplant outdoors (fall) | Jul 4 – Jul 15 |
| Cabbage | Start seeds indoors (spring) | Mar 5 – Apr 2 |
| Cabbage | Transplant outdoors (spring) | Apr 2 – May 3 |
| Cabbage | Start seeds indoors (fall) | May 25 – Jun 24 |
| Cabbage | Transplant outdoors (fall) | Jun 24 – Jul 25 |
| Leaf lettuce | Sow outdoors (spring) | Apr 2 – Jun 18 |
| Leaf lettuce | Sow outdoors (fall) | Jun 24 – Aug 10 |
| Spinach | Sow outdoors (spring) | Mar 26 – May 9 |
| Spinach | Sow outdoors (fall) | Jul 11 – Aug 15 |
| Radishes | Sow outdoors (spring) | Apr 2 – May 23 |
| Radishes | Sow outdoors (fall) | Jun 24 – Aug 25 |
| Kale | Sow outdoors (spring) | Apr 19 – May 9 |
| Kale | Sow outdoors (fall) | Jun 17 – Jul 25 |
| Carrots | Sow outdoors (spring) | May 3 – Jun 18 |
| Carrots | Sow outdoors (fall) | May 25 – Jul 10 |
| Garlic | Plant outdoors (fall) | Sep 24 – Oct 25 |
Where these dates come from
ZIP code 59330 is matched to the NOAA station Glendive, MT, 1 km away, at 2,075 ft elevation (18 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Glendive, MT (used) | 2,075 ft | May 3 | Oct 4 |
| Mildred 5 N, MT | 2,482 ft | May 20 | Sep 22 |
| Wibaux 2 E, MT | 2,696 ft | May 27 | Sep 16 |
| Savage, MT | 1,978 ft | May 12 | Sep 25 |
Frost dates near Glendive
- Lindsay, MT 59339 · last May 26, first Sep 17
- Bloomfield, MT 59315 · last May 17, first Sep 22
- Wibaux, MT 59353 · last May 27, first Sep 16
- Fallon, MT 59326 · last May 20, first Sep 22
- Mildred, MT 59341 · last May 20, first Sep 22
- Terry, MT 59349 · last May 12, first Sep 28
- Savage, MT 59262 · last May 12, first Sep 25
- Beach, ND 58621 · last May 16, first Sep 26
Frequently asked questions
- When is the last frost in Glendive, MT?
- For ZIP code 59330, the average last spring frost (32°F) is May 3, based on NOAA 1991-2020 climate normals for the Glendive, MT weather station. There is a 1-in-10 chance of a frost after May 16.
- When is the first frost in Glendive, MT?
- The average first fall frost (32°F) is October 4. There is a 1-in-10 chance of frost by September 22, so tender plants are at risk from that point on.
- How long is the growing season in 59330?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 153 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.