Frost dates for 49705Afton, MI
The average last spring frost in Afton is June 7 and the average first fall frost is September 14, giving a typical growing season of about 95 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Jun 7
- Average first fall frost
- Sep 14
- Growing season
- 95 days
Safer after Jun 29 (1-in-10 risk)
Possible by Aug 24 (1-in-10 risk)
Last frost typically in 217 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) | — | — | 63 days | 100% |
| Frost / freeze (32°F) | May 23 · Jun 7 · Jun 29 | Aug 24 · Sep 14 · Sep 30 | 95 days | 100% |
| Hard freeze (28°F) | May 5 · May 24 · Jun 9 | Sep 12 · Sep 29 · Oct 15 | 126 days | 100% |
Planting calendar for Afton
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 7 – Jul 13 |
| Tomatoes | Transplant outdoors | Jun 23 – May 25 |
| Peppers | Start seeds indoors | May 7 – Jun 7 |
| Peppers | Transplant outdoors | Jul 7 – Aug 7 |
| Eggplant | Start seeds indoors | May 24 – Jun 22 |
| Eggplant | Transplant outdoors | Jul 7 – Aug 7 |
| Cucumbers | Sow outdoors | Jul 7 – Jun 4 |
| Summer squash | Sow outdoors | Jun 23 – Aug 7 |
| Winter squash & pumpkins | Sow outdoors | Jul 7 – Aug 7 |
| Snap beans | Sow outdoors | Jun 23 – Jun 27 |
| Sweet corn | Sow outdoors | Jun 23 – May 25 |
| Watermelon & cantaloupe | Sow outdoors | Jul 7 – Aug 7 |
| Okra | Sow outdoors | Jun 30 – Jul 23 |
| Peas | Sow outdoors (spring) | May 7 – Jun 22 |
| Potatoes | Plant outdoors (spring) | May 7 – Jul 7 |
| Onions | Start seeds indoors (spring) | Mar 26 – Apr 22 |
| Onions | Transplant outdoors (spring) | May 24 – Jun 22 |
| Broccoli | Start seeds indoors (spring) | Apr 19 – May 23 |
| Broccoli | Transplant outdoors (spring) | May 24 – Jun 22 |
| Broccoli | Start seeds indoors (fall) | May 15 – May 25 |
| Broccoli | Transplant outdoors (fall) | Jun 14 – Jun 25 |
| Cabbage | Start seeds indoors (spring) | Apr 9 – May 7 |
| Cabbage | Transplant outdoors (spring) | May 7 – Jun 7 |
| Cabbage | Start seeds indoors (fall) | May 5 – Jun 4 |
| Cabbage | Transplant outdoors (fall) | Jun 4 – Jul 5 |
| Leaf lettuce | Sow outdoors (spring) | May 7 – Jul 23 |
| Leaf lettuce | Sow outdoors (fall) | Jun 4 – Jul 21 |
| Spinach | Sow outdoors (spring) | Apr 30 – Jun 13 |
| Spinach | Sow outdoors (fall) | Jun 21 – Jul 26 |
| Radishes | Sow outdoors (spring) | May 7 – Jun 27 |
| Radishes | Sow outdoors (fall) | Jun 4 – Aug 5 |
| Kale | Sow outdoors (spring) | May 24 – Jun 13 |
| Kale | Sow outdoors (fall) | May 28 – Jul 5 |
| Carrots | Sow outdoors (spring) | Jun 7 – Jul 23 |
| Carrots | Sow outdoors (fall) | May 5 – Jun 20 |
| Garlic | Plant outdoors (fall) | Sep 4 – Oct 5 |
Where these dates come from
ZIP code 49705 is matched to the NOAA station Vanderbilt 11Ene, MI, 21.6 km away, at 905 ft elevation (49 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Vanderbilt 11Ene, MI (used) | 905 ft | Jun 7 | Sep 14 |
| Onaway 4N, MI | 745 ft | May 22 | Oct 2 |
| Cheboygan, MI | 588 ft | May 11 | Oct 11 |
| Pellston Rgnl Ap, MI | 705 ft | May 31 | Sep 18 |
Frost dates near Afton
- Indian River, MI 49749 · last May 31, first Sep 18
- Tower, MI 49792 · last May 22, first Oct 2
- Wolverine, MI 49799 · last Jun 7, first Sep 14
- Topinabee, MI 49791 · last May 31, first Sep 18
- Onaway, MI 49765 · last May 22, first Oct 2
- Burt Lake, MI 49717 · last May 31, first Sep 18
- Mullett Lake, MI 49761 · last May 11, first Oct 11
- Alanson, MI 49706 · last May 31, first Sep 18
Frequently asked questions
- When is the last frost in Afton, MI?
- For ZIP code 49705, the average last spring frost (32°F) is June 7, based on NOAA 1991-2020 climate normals for the Vanderbilt 11Ene, MI weather station. There is a 1-in-10 chance of a frost after June 29.
- When is the first frost in Afton, MI?
- The average first fall frost (32°F) is September 14. There is a 1-in-10 chance of frost by August 24, so tender plants are at risk from that point on.
- How long is the growing season in 49705?
- 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.