Frost dates for 48656Saint Helen, MI
The average last spring frost in Saint Helen is May 19 and the average first fall frost is September 23, giving a typical growing season of about 125 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 19
- Average first fall frost
- Sep 23
- Growing season
- 125 days
Safer after Jun 3 (1-in-10 risk)
Possible by Sep 6 (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 20 · Jun 3 · Jun 30 | Aug 20 · Sep 8 · Sep 25 | 95 days | 100% |
| Frost / freeze (32°F) | Apr 30 · May 19 · Jun 3 | Sep 6 · Sep 23 · Oct 7 | 125 days | 100% |
| Hard freeze (28°F) | Apr 17 · May 4 · May 24 | Sep 21 · Oct 5 · Oct 25 | 154 days | 100% |
Planting calendar for Saint Helen
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 18 – Jun 24 |
| Tomatoes | Transplant outdoors | Jun 4 – Jun 3 |
| Peppers | Start seeds indoors | Apr 18 – May 19 |
| Peppers | Transplant outdoors | Jun 18 – Jul 19 |
| Eggplant | Start seeds indoors | May 5 – Jun 3 |
| Eggplant | Transplant outdoors | Jun 18 – Jul 19 |
| Cucumbers | Sow outdoors | Jun 18 – Jun 13 |
| Summer squash | Sow outdoors | Jun 4 – Jul 19 |
| Winter squash & pumpkins | Sow outdoors | Jun 18 – Jul 19 |
| Snap beans | Sow outdoors | Jun 4 – Jul 6 |
| Sweet corn | Sow outdoors | Jun 4 – Jun 3 |
| Watermelon & cantaloupe | Sow outdoors | Jun 18 – Jul 19 |
| Okra | Sow outdoors | Jun 11 – Jul 4 |
| Peas | Sow outdoors (spring) | Apr 18 – Jun 3 |
| Potatoes | Plant outdoors (spring) | Apr 18 – Jun 18 |
| Onions | Start seeds indoors (spring) | Mar 7 – Apr 3 |
| Onions | Transplant outdoors (spring) | May 5 – Jun 3 |
| Broccoli | Start seeds indoors (spring) | Mar 31 – May 4 |
| Broccoli | Transplant outdoors (spring) | May 5 – Jun 3 |
| Broccoli | Start seeds indoors (fall) | May 24 – Jun 3 |
| Broccoli | Transplant outdoors (fall) | Jun 23 – Jul 4 |
| Cabbage | Start seeds indoors (spring) | Mar 21 – Apr 18 |
| Cabbage | Transplant outdoors (spring) | Apr 18 – May 19 |
| Cabbage | Start seeds indoors (fall) | May 14 – Jun 13 |
| Cabbage | Transplant outdoors (fall) | Jun 13 – Jul 14 |
| Leaf lettuce | Sow outdoors (spring) | Apr 18 – Jul 4 |
| Leaf lettuce | Sow outdoors (fall) | Jun 13 – Jul 30 |
| Spinach | Sow outdoors (spring) | Apr 11 – May 25 |
| Spinach | Sow outdoors (fall) | Jun 30 – Aug 4 |
| Radishes | Sow outdoors (spring) | Apr 18 – Jun 8 |
| Radishes | Sow outdoors (fall) | Jun 13 – Aug 14 |
| Kale | Sow outdoors (spring) | May 5 – May 25 |
| Kale | Sow outdoors (fall) | Jun 6 – Jul 14 |
| Carrots | Sow outdoors (spring) | May 19 – Jul 4 |
| Carrots | Sow outdoors (fall) | May 14 – Jun 29 |
| Garlic | Plant outdoors (fall) | Sep 13 – Oct 14 |
Where these dates come from
ZIP code 48656 is matched to the NOAA station Houghton Lk Roscommon Ap, MI, 19.8 km away, at 1,151 ft elevation (14 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Houghton Lk Roscommon Ap, MI (used) | 1,151 ft | May 19 | Sep 23 |
| W Branch 3Se, MI | 885 ft | May 15 | Oct 4 |
| Houghton Lake 2Nw, MI | 1,161 ft | May 20 | Oct 1 |
| Lupton 1S, MI | 908 ft | May 21 | Sep 29 |
Frost dates near Saint Helen
- West Branch, MI 48661 · last May 15, first Oct 4
- Prudenville, MI 48651 · last May 19, first Sep 23
- Higgins Lake, MI 48627 · last May 19, first Sep 23
- Roscommon, MI 48653 · last May 19, first Sep 23
- Rose City, MI 48654 · last May 21, first Sep 29
- Houghton Lake, MI 48629 · last May 19, first Sep 23
- Luzerne, MI 48636 · last May 19, first Oct 2
- Houghton Lake Heights, MI 48630 · last May 19, first Sep 23
Frequently asked questions
- When is the last frost in Saint Helen, MI?
- For ZIP code 48656, the average last spring frost (32°F) is May 19, based on NOAA 1991-2020 climate normals for the Houghton Lk Roscommon Ap, MI weather station. There is a 1-in-10 chance of a frost after June 3.
- When is the first frost in Saint Helen, MI?
- The average first fall frost (32°F) is September 23. There is a 1-in-10 chance of frost by September 6, so tender plants are at risk from that point on.
- How long is the growing season in 48656?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 125 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.