Frost dates for 49915Caspian, MI
The average last spring frost in Caspian is June 4 and the average first fall frost is September 10, giving a typical growing season of about 95 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Jun 4
- Average first fall frost
- Sep 10
- Growing season
- 95 days
Safer after Jun 26 (1-in-10 risk)
Possible by Aug 21 (1-in-10 risk)
Last frost typically in 220 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) | — | — | 58 days | 100% |
| Frost / freeze (32°F) | May 22 · Jun 4 · Jun 26 | Aug 21 · Sep 10 · Sep 25 | 95 days | 100% |
| Hard freeze (28°F) | May 7 · May 23 · Jun 6 | Sep 7 · Sep 24 · Oct 8 | 123 days | 100% |
Planting calendar for Caspian
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 21 |
| 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 – May 31 |
| Summer squash | Sow outdoors | Jun 20 – Aug 4 |
| Winter squash & pumpkins | Sow outdoors | Jul 4 – Aug 4 |
| Snap beans | Sow outdoors | Jun 20 – Jun 23 |
| Sweet corn | Sow outdoors | Jun 20 – May 21 |
| 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 11 – May 21 |
| Broccoli | Transplant outdoors (fall) | Jun 10 – Jun 21 |
| Cabbage | Start seeds indoors (spring) | Apr 6 – May 4 |
| Cabbage | Transplant outdoors (spring) | May 4 – Jun 4 |
| Cabbage | Start seeds indoors (fall) | May 1 – May 31 |
| Cabbage | Transplant outdoors (fall) | May 31 – Jul 1 |
| Leaf lettuce | Sow outdoors (spring) | May 4 – Jul 20 |
| Leaf lettuce | Sow outdoors (fall) | May 31 – Jul 17 |
| Spinach | Sow outdoors (spring) | Apr 27 – Jun 10 |
| Spinach | Sow outdoors (fall) | Jun 17 – Jul 22 |
| Radishes | Sow outdoors (spring) | May 4 – Jun 24 |
| Radishes | Sow outdoors (fall) | May 31 – Aug 1 |
| Kale | Sow outdoors (spring) | May 21 – Jun 10 |
| Kale | Sow outdoors (fall) | May 24 – Jul 1 |
| Carrots | Sow outdoors (spring) | Jun 4 – Jul 20 |
| Carrots | Sow outdoors (fall) | May 1 – Jun 16 |
| Garlic | Plant outdoors (fall) | Aug 31 – Oct 1 |
Where these dates come from
ZIP code 49915 is matched to the NOAA station Stambaugh 2Sse, MI, 1.1 km away, at 1,450 ft elevation (43 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Stambaugh 2Sse, MI (used) | 1,450 ft | Jun 4 | Sep 10 |
| Amasa 1W, MI | 1,470 ft | Jun 6 | Sep 9 |
| Florence, WI | 1,300 ft | May 24 | Sep 25 |
| Iron Mtn Ford Ap, MI | 1,149 ft | May 25 | Sep 24 |
Frost dates near Caspian
- Stambaugh, MI 49964 · last Jun 4, first Sep 10
- Iron River, MI 49935 · last Jun 4, first Sep 10
- Gaastra, MI 49927 · last Jun 4, first Sep 10
- Long Lake, WI 54542 · last Jun 4, first Sep 10
- Alpha, MI 49902 · last May 24, first Sep 25
- Crystal Falls, MI 49920 · last Jun 6, first Sep 9
- Amasa, MI 49903 · last Jun 6, first Sep 9
- Phelps, WI 54554 · last May 25, first Sep 24
Frequently asked questions
- When is the last frost in Caspian, MI?
- For ZIP code 49915, the average last spring frost (32°F) is June 4, based on NOAA 1991-2020 climate normals for the Stambaugh 2Sse, MI weather station. There is a 1-in-10 chance of a frost after June 26.
- When is the first frost in Caspian, MI?
- The average first fall frost (32°F) is September 10. There is a 1-in-10 chance of frost by August 21, so tender plants are at risk from that point on.
- How long is the growing season in 49915?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 95 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.