Frost dates for 59547Zurich, MT
The average last spring frost in Zurich is May 14 and the average first fall frost is September 23, giving a typical growing season of about 130 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 14
- Average first fall frost
- Sep 23
- Growing season
- 130 days
Safer after May 27 (1-in-10 risk)
Possible by Sep 11 (1-in-10 risk)
Last frost typically in 192 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 25 · Jun 8 | Sep 1 · Sep 12 · Sep 24 | 109 days | 100% |
| Frost / freeze (32°F) | May 1 · May 14 · May 27 | Sep 11 · Sep 23 · Oct 3 | 130 days | 100% |
| Hard freeze (28°F) | Apr 19 · May 3 · May 16 | Sep 20 · Oct 1 · Oct 11 | 149 days | 100% |
Planting calendar for Zurich
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 13 – Jun 19 |
| Tomatoes | Transplant outdoors | May 30 – Jun 3 |
| Peppers | Start seeds indoors | Apr 13 – May 14 |
| Peppers | Transplant outdoors | Jun 13 – Jul 14 |
| Eggplant | Start seeds indoors | Apr 30 – May 29 |
| Eggplant | Transplant outdoors | Jun 13 – Jul 14 |
| Cucumbers | Sow outdoors | Jun 13 – Jun 13 |
| Summer squash | Sow outdoors | May 30 – Jul 14 |
| Winter squash & pumpkins | Sow outdoors | Jun 13 – Jul 14 |
| Snap beans | Sow outdoors | May 30 – Jul 6 |
| Sweet corn | Sow outdoors | May 30 – Jun 3 |
| Watermelon & cantaloupe | Sow outdoors | Jun 13 – Jul 14 |
| Okra | Sow outdoors | Jun 6 – Jun 29 |
| Peas | Sow outdoors (spring) | Apr 13 – May 29 |
| Potatoes | Plant outdoors (spring) | Apr 13 – Jun 13 |
| Onions | Start seeds indoors (spring) | Mar 2 – Mar 29 |
| Onions | Transplant outdoors (spring) | Apr 30 – May 29 |
| Broccoli | Start seeds indoors (spring) | Mar 26 – Apr 29 |
| Broccoli | Transplant outdoors (spring) | Apr 30 – May 29 |
| Broccoli | Start seeds indoors (fall) | May 24 – Jun 3 |
| Broccoli | Transplant outdoors (fall) | Jun 23 – Jul 4 |
| Cabbage | Start seeds indoors (spring) | Mar 16 – Apr 13 |
| Cabbage | Transplant outdoors (spring) | Apr 13 – May 14 |
| Cabbage | Start seeds indoors (fall) | May 14 – Jun 13 |
| Cabbage | Transplant outdoors (fall) | Jun 13 – Jul 14 |
| Leaf lettuce | Sow outdoors (spring) | Apr 13 – Jun 29 |
| Leaf lettuce | Sow outdoors (fall) | Jun 13 – Jul 30 |
| Spinach | Sow outdoors (spring) | Apr 6 – May 20 |
| Spinach | Sow outdoors (fall) | Jun 30 – Aug 4 |
| Radishes | Sow outdoors (spring) | Apr 13 – Jun 3 |
| Radishes | Sow outdoors (fall) | Jun 13 – Aug 14 |
| Kale | Sow outdoors (spring) | Apr 30 – May 20 |
| Kale | Sow outdoors (fall) | Jun 6 – Jul 14 |
| Carrots | Sow outdoors (spring) | May 14 – Jun 29 |
| Carrots | Sow outdoors (fall) | May 14 – Jun 29 |
| Garlic | Plant outdoors (fall) | Sep 13 – Oct 14 |
Where these dates come from
ZIP code 59547 is matched to the NOAA station Chinook, MT, 14.4 km away, at 2,420 ft elevation (35 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Chinook, MT (used) | 2,420 ft | May 14 | Sep 23 |
| Harlem, MT | 2,371 ft | May 16 | Sep 21 |
| Ft Belknap 2 Sw, MT | 2,527 ft | May 16 | Sep 22 |
| Chinook 35Se, MT | 3,360 ft | May 23 | Sep 23 |
Frost dates near Zurich
- Chinook, MT 59523 · last May 14, first Sep 23
- Harlem, MT 59526 · last May 16, first Sep 21
- Hogeland, MT 59529 · last May 19, first Sep 21
- Havre, MT 59501 · last May 15, first Sep 23
- Turner, MT 59542 · last May 19, first Sep 21
- Dodson, MT 59524 · last May 10, first Sep 29
- Box Elder, MT 59521 · last May 17, first Sep 25
- Hays, MT 59527 · last May 18, first Sep 23
Frequently asked questions
- When is the last frost in Zurich, MT?
- For ZIP code 59547, the average last spring frost (32°F) is May 14, based on NOAA 1991-2020 climate normals for the Chinook, MT weather station. There is a 1-in-10 chance of a frost after May 27.
- When is the first frost in Zurich, MT?
- The average first fall frost (32°F) is September 23. There is a 1-in-10 chance of frost by September 11, so tender plants are at risk from that point on.
- How long is the growing season in 59547?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 130 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.