Frost dates for 59332Hammond, MT
The average last spring frost in Hammond is May 17 and the average first fall frost is September 22, giving a typical growing season of about 127 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 17
- Average first fall frost
- Sep 22
- Growing season
- 127 days
Safer after Jun 1 (1-in-10 risk)
Possible by Sep 5 (1-in-10 risk)
Last frost typically in 197 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 17 | Aug 24 · Sep 12 · Sep 26 | 103 days | 100% |
| Frost / freeze (32°F) | May 5 · May 17 · Jun 1 | Sep 5 · Sep 22 · Oct 5 | 127 days | 100% |
| Hard freeze (28°F) | Apr 23 · May 6 · May 21 | Sep 15 · Oct 1 · Oct 15 | 147 days | 100% |
Planting calendar for Hammond
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 16 – Jun 22 |
| Tomatoes | Transplant outdoors | Jun 2 – Jun 2 |
| Peppers | Start seeds indoors | Apr 16 – May 17 |
| Peppers | Transplant outdoors | Jun 16 – Jul 17 |
| Eggplant | Start seeds indoors | May 3 – Jun 1 |
| Eggplant | Transplant outdoors | Jun 16 – Jul 17 |
| Cucumbers | Sow outdoors | Jun 16 – Jun 12 |
| Summer squash | Sow outdoors | Jun 2 – Jul 17 |
| Winter squash & pumpkins | Sow outdoors | Jun 16 – Jul 17 |
| Snap beans | Sow outdoors | Jun 2 – Jul 5 |
| Sweet corn | Sow outdoors | Jun 2 – Jun 2 |
| Watermelon & cantaloupe | Sow outdoors | Jun 16 – Jul 17 |
| Okra | Sow outdoors | Jun 9 – Jul 2 |
| Peas | Sow outdoors (spring) | Apr 16 – Jun 1 |
| Potatoes | Plant outdoors (spring) | Apr 16 – Jun 16 |
| Onions | Start seeds indoors (spring) | Mar 5 – Apr 1 |
| Onions | Transplant outdoors (spring) | May 3 – Jun 1 |
| Broccoli | Start seeds indoors (spring) | Mar 29 – May 2 |
| Broccoli | Transplant outdoors (spring) | May 3 – Jun 1 |
| Broccoli | Start seeds indoors (fall) | May 23 – Jun 2 |
| Broccoli | Transplant outdoors (fall) | Jun 22 – Jul 3 |
| Cabbage | Start seeds indoors (spring) | Mar 19 – Apr 16 |
| Cabbage | Transplant outdoors (spring) | Apr 16 – May 17 |
| Cabbage | Start seeds indoors (fall) | May 13 – Jun 12 |
| Cabbage | Transplant outdoors (fall) | Jun 12 – Jul 13 |
| Leaf lettuce | Sow outdoors (spring) | Apr 16 – Jul 2 |
| Leaf lettuce | Sow outdoors (fall) | Jun 12 – Jul 29 |
| Spinach | Sow outdoors (spring) | Apr 9 – May 23 |
| Spinach | Sow outdoors (fall) | Jun 29 – Aug 3 |
| Radishes | Sow outdoors (spring) | Apr 16 – Jun 6 |
| Radishes | Sow outdoors (fall) | Jun 12 – Aug 13 |
| Kale | Sow outdoors (spring) | May 3 – May 23 |
| Kale | Sow outdoors (fall) | Jun 5 – Jul 13 |
| Carrots | Sow outdoors (spring) | May 17 – Jul 2 |
| Carrots | Sow outdoors (fall) | May 13 – Jun 28 |
| Garlic | Plant outdoors (fall) | Sep 12 – Oct 13 |
Where these dates come from
ZIP code 59332 is matched to the NOAA station Ridgeway 1 S, MT, 10.1 km away, at 3,316 ft elevation (11 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Ridgeway 1 S, MT (used) | 3,316 ft | May 17 | Sep 22 |
| Ekalaka, MT | 3,432 ft | May 20 | Sep 23 |
| Camp Crook, SD | 3,120 ft | May 17 | Sep 24 |
| Albion 1 N, MT | 3,312 ft | Jun 2 | Sep 6 |
Frost dates near Hammond
- Ekalaka, MT 59324 · last May 20, first Sep 23
- Capitol, MT 59319 · last May 17, first Sep 24
- Camp Crook, SD 57724 · last May 17, first Sep 24
- Powderville, MT 59345 · last May 13, first Sep 25
- Alzada, MT 59311 · last Jun 2, first Sep 6
- Boyes, MT 59316 · last May 16, first Sep 28
- Broadus, MT 59317 · last May 14, first Sep 28
- Willard, MT 59354 · last May 16, first Sep 26
Frequently asked questions
- When is the last frost in Hammond, MT?
- For ZIP code 59332, the average last spring frost (32°F) is May 17, based on NOAA 1991-2020 climate normals for the Ridgeway 1 S, MT weather station. There is a 1-in-10 chance of a frost after June 1.
- When is the first frost in Hammond, MT?
- The average first fall frost (32°F) is September 22. There is a 1-in-10 chance of frost by September 5, so tender plants are at risk from that point on.
- How long is the growing season in 59332?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 127 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.