Frost dates for 59720Cameron, MT
The average last spring frost in Cameron is June 4 and the average first fall frost is September 18, giving a typical growing season of about 106 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Jun 4
- Average first fall frost
- Sep 18
- Growing season
- 106 days
Safer after Jun 23 (1-in-10 risk)
Possible by Sep 3 (1-in-10 risk)
Last frost typically in 213 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) | Jun 5 · Jun 20 · Jul 6 | Aug 23 · Sep 6 · Sep 20 | 77 days | 100% |
| Frost / freeze (32°F) | May 17 · Jun 4 · Jun 23 | Sep 3 · Sep 18 · Oct 2 | 106 days | 100% |
| Hard freeze (28°F) | May 1 · May 14 · Jun 3 | Sep 13 · Oct 1 · Oct 14 | 137 days | 100% |
Planting calendar for Cameron
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 | May 4 – Jul 10 |
| Tomatoes | Transplant outdoors | Jun 20 – May 29 |
| Peppers | Start seeds indoors | May 4 – Jun 4 |
| Peppers | Transplant outdoors | Jul 4 – Aug 4 |
| Eggplant | Start seeds indoors | May 21 – Jun 19 |
| Eggplant | Transplant outdoors | Jul 4 – Aug 4 |
| Cucumbers | Sow outdoors | Jul 4 – Jun 8 |
| Summer squash | Sow outdoors | Jun 20 – Aug 4 |
| Winter squash & pumpkins | Sow outdoors | Jul 4 – Aug 4 |
| Snap beans | Sow outdoors | Jun 20 – Jul 1 |
| Sweet corn | Sow outdoors | Jun 20 – May 29 |
| Watermelon & cantaloupe | Sow outdoors | Jul 4 – Aug 4 |
| Okra | Sow outdoors | Jun 27 – Jul 20 |
| Peas | Sow outdoors (spring) | May 4 – Jun 19 |
| Potatoes | Plant outdoors (spring) | May 4 – Jul 4 |
| Onions | Start seeds indoors (spring) | Mar 23 – Apr 19 |
| Onions | Transplant outdoors (spring) | May 21 – Jun 19 |
| Broccoli | Start seeds indoors (spring) | Apr 16 – May 20 |
| Broccoli | Transplant outdoors (spring) | May 21 – Jun 19 |
| Broccoli | Start seeds indoors (fall) | May 19 – May 29 |
| Broccoli | Transplant outdoors (fall) | Jun 18 – Jun 29 |
| Cabbage | Start seeds indoors (spring) | Apr 6 – May 4 |
| Cabbage | Transplant outdoors (spring) | May 4 – Jun 4 |
| Cabbage | Start seeds indoors (fall) | May 9 – Jun 8 |
| Cabbage | Transplant outdoors (fall) | Jun 8 – Jul 9 |
| Leaf lettuce | Sow outdoors (spring) | May 4 – Jul 20 |
| Leaf lettuce | Sow outdoors (fall) | Jun 8 – Jul 25 |
| Spinach | Sow outdoors (spring) | Apr 27 – Jun 10 |
| Spinach | Sow outdoors (fall) | Jun 25 – Jul 30 |
| Radishes | Sow outdoors (spring) | May 4 – Jun 24 |
| Radishes | Sow outdoors (fall) | Jun 8 – Aug 9 |
| Kale | Sow outdoors (spring) | May 21 – Jun 10 |
| Kale | Sow outdoors (fall) | Jun 1 – Jul 9 |
| Carrots | Sow outdoors (spring) | Jun 4 – Jul 20 |
| Carrots | Sow outdoors (fall) | May 9 – Jun 24 |
| Garlic | Plant outdoors (fall) | Sep 8 – Oct 9 |
Where these dates come from
ZIP code 59720 is matched to the NOAA station Virginia City, MT, 28.9 km away, at 5,773 ft elevation (202 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Virginia City, MT (used) | 5,773 ft | Jun 4 | Sep 18 |
| Ennis, MT | 4,953 ft | Jun 16 | Sep 4 |
| Big Sky 2Wnw, MT | 6,590 ft | — | — |
| Alder 17 S, MT | 5,850 ft | Jun 6 | Sep 14 |
Frost dates near Cameron
- Ennis, MT 59729 · last Jun 16, first Sep 4
- Big Sky, MT 59716 · last —, first —
- Virginia City, MT 59755 · last Jun 4, first Sep 18
- Mc Allister, MT 59740 · last Jun 16, first Sep 4
- Alder, MT 59710 · last Jun 6, first Sep 14
- Gallatin Gateway, MT 59730 · last —, first —
- Norris, MT 59745 · last Apr 30, first Oct 10
- Sheridan, MT 59749 · last May 24, first Sep 22
Frequently asked questions
- When is the last frost in Cameron, MT?
- For ZIP code 59720, the average last spring frost (32°F) is June 4, based on NOAA 1991-2020 climate normals for the Virginia City, MT weather station. There is a 1-in-10 chance of a frost after June 23.
- When is the first frost in Cameron, MT?
- The average first fall frost (32°F) is September 18. There is a 1-in-10 chance of frost by September 3, so tender plants are at risk from that point on.
- How long is the growing season in 59720?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 106 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.