Frost dates for 48550Flint, MI
The average last spring frost in Flint is May 3 and the average first fall frost is October 13, giving a typical growing season of about 162 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 3
- Average first fall frost
- Oct 13
- Growing season
- 162 days
Safer after May 20 (1-in-10 risk)
Possible by Sep 30 (1-in-10 risk)
Last frost typically in 184 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) | Apr 29 · May 14 · May 29 | Sep 20 · Oct 2 · Oct 13 | 141 days | 100% |
| Frost / freeze (32°F) | Apr 20 · May 3 · May 20 | Sep 30 · Oct 13 · Oct 27 | 162 days | 100% |
| Hard freeze (28°F) | Apr 8 · Apr 22 · May 9 | Oct 12 · Oct 27 · Nov 9 | 186 days | 100% |
Planting calendar for Flint
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 2 – Jun 8 |
| Tomatoes | Transplant outdoors | May 19 – Jun 23 |
| Peppers | Start seeds indoors | Apr 2 – May 3 |
| Peppers | Transplant outdoors | Jun 2 – Jul 3 |
| Eggplant | Start seeds indoors | Apr 19 – May 18 |
| Eggplant | Transplant outdoors | Jun 2 – Jul 3 |
| Cucumbers | Sow outdoors | Jun 2 – Jul 3 |
| Summer squash | Sow outdoors | May 19 – Jul 3 |
| Winter squash & pumpkins | Sow outdoors | Jun 2 – Jul 3 |
| Snap beans | Sow outdoors | May 19 – Jul 26 |
| Sweet corn | Sow outdoors | May 19 – Jun 23 |
| Watermelon & cantaloupe | Sow outdoors | Jun 2 – Jul 3 |
| Okra | Sow outdoors | May 26 – Jun 18 |
| Peas | Sow outdoors (spring) | Apr 2 – May 18 |
| Potatoes | Plant outdoors (spring) | Apr 2 – Jun 2 |
| Onions | Start seeds indoors (spring) | Feb 19 – Mar 18 |
| Onions | Transplant outdoors (spring) | Apr 19 – May 18 |
| Broccoli | Start seeds indoors (spring) | Mar 15 – Apr 18 |
| Broccoli | Transplant outdoors (spring) | Apr 19 – May 18 |
| Broccoli | Start seeds indoors (fall) | Jun 13 – Jun 23 |
| Broccoli | Transplant outdoors (fall) | Jul 13 – Jul 24 |
| Cabbage | Start seeds indoors (spring) | Mar 5 – Apr 2 |
| Cabbage | Transplant outdoors (spring) | Apr 2 – May 3 |
| Cabbage | Start seeds indoors (fall) | Jun 3 – Jul 3 |
| Cabbage | Transplant outdoors (fall) | Jul 3 – Aug 3 |
| Leaf lettuce | Sow outdoors (spring) | Apr 2 – Jun 18 |
| Leaf lettuce | Sow outdoors (fall) | Jul 3 – Aug 19 |
| Spinach | Sow outdoors (spring) | Mar 26 – May 9 |
| Spinach | Sow outdoors (fall) | Jul 20 – Aug 24 |
| Radishes | Sow outdoors (spring) | Apr 2 – May 23 |
| Radishes | Sow outdoors (fall) | Jul 3 – Sep 3 |
| Kale | Sow outdoors (spring) | Apr 19 – May 9 |
| Kale | Sow outdoors (fall) | Jun 26 – Aug 3 |
| Carrots | Sow outdoors (spring) | May 3 – Jun 18 |
| Carrots | Sow outdoors (fall) | Jun 3 – Jul 19 |
| Garlic | Plant outdoors (fall) | Oct 3 – Nov 3 |
Where these dates come from
ZIP code 48550 is matched to the NOAA station Flint 7W, MI, 6.6 km away, at 679 ft elevation (62 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Flint 7W, MI (used) | 679 ft | May 3 | Oct 13 |
| Burton 4N, MI | 757 ft | May 8 | Oct 5 |
| Flint Bishop Intl Ap, MI | 770 ft | May 6 | Oct 10 |
| Goodrich, MI | 910 ft | May 1 | Oct 14 |
Frost dates near Flint
- Flint, MI 48502 · last May 3, first Oct 13
- Burton, MI 48509 · last May 6, first Oct 10
- Mount Morris, MI 48458 · last May 3, first Oct 13
- Genesee, MI 48437 · last May 3, first Oct 13
- Grand Blanc, MI 48439 · last May 1, first Oct 14
- Flushing, MI 48433 · last May 3, first Oct 13
- Davison, MI 48423 · last May 1, first Oct 14
- Swartz Creek, MI 48473 · last May 6, first Oct 10
Frequently asked questions
- When is the last frost in Flint, MI?
- For ZIP code 48550, the average last spring frost (32°F) is May 3, based on NOAA 1991-2020 climate normals for the Flint 7W, MI weather station. There is a 1-in-10 chance of a frost after May 20.
- When is the first frost in Flint, MI?
- The average first fall frost (32°F) is October 13. There is a 1-in-10 chance of frost by September 30, so tender plants are at risk from that point on.
- How long is the growing season in 48550?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 162 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.