Frost dates for 59746Polaris, MT
Frost is possible in any month near Polaris, based on NOAA 1991-2020 records for the Jackson, MT station.
Frost is possible in any month. Even summer nights can drop to freezing at this station, so protect tender plants whenever cold nights are forecast.
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) | — | — | 25 days | 100% |
| Frost / freeze (32°F) | — | — | 51 days | 100% |
| Hard freeze (28°F) | May 23 · Jun 10 · Jul 1 | Aug 19 · Sep 4 · Sep 18 | 83 days | 100% |
Where these dates come from
ZIP code 59746 is matched to the NOAA station Jackson, MT, 22.6 km away, at 6,480 ft elevation (128 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Jackson, MT (used) | 6,480 ft | — | — |
| Dillon 18 Wsw, MT | 5,971 ft | — | — |
| Glen 4 N, MT | 5,054 ft | — | — |
| Wisdom, MT | 6,060 ft | — | — |
Frost dates near Polaris
- Jackson, MT 59736 · last —, first —
- Glen, MT 59732 · last —, first —
- Dillon, MT 59725 · last Jun 5, first Sep 13
- Wisdom, MT 59761 · last —, first —
- Wise River, MT 59762 · last —, first —
- Melrose, MT 59743 · last Jun 10, first Sep 7
- Divide, MT 59727 · last —, first —
- Carmen, ID 83462 · last May 17, first Sep 24
Frequently asked questions
- When is the last frost in Polaris, MT?
- Frost is possible in any month at the nearest NOAA station (Jackson, MT), so there is no reliable average last frost date.
- When is the first frost in Polaris, MT?
- Frost is possible in any month at the nearest NOAA station.
- 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.