Frost dates for 55603Finland, MN
The average last spring frost in Finland is May 15 and the average first fall frost is October 1, giving a typical growing season of about 137 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 15
- Average first fall frost
- Oct 1
- Growing season
- 137 days
Safer after May 31 (1-in-10 risk)
Possible by Sep 17 (1-in-10 risk)
Last frost typically in 200 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 14 · May 30 · Jun 11 | Sep 6 · Sep 20 · Oct 3 | 114 days | 100% |
| Frost / freeze (32°F) | Apr 30 · May 15 · May 31 | Sep 17 · Oct 1 · Oct 14 | 137 days | 100% |
| Hard freeze (28°F) | Apr 19 · May 2 · May 20 | Sep 27 · Oct 10 · Oct 28 | 160 days | 100% |
Planting calendar for Finland
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 14 – Jun 20 |
| Tomatoes | Transplant outdoors | May 31 – Jun 11 |
| Peppers | Start seeds indoors | Apr 14 – May 15 |
| Peppers | Transplant outdoors | Jun 14 – Jul 15 |
| Eggplant | Start seeds indoors | May 1 – May 30 |
| Eggplant | Transplant outdoors | Jun 14 – Jul 15 |
| Cucumbers | Sow outdoors | Jun 14 – Jun 21 |
| Summer squash | Sow outdoors | May 31 – Jul 15 |
| Winter squash & pumpkins | Sow outdoors | Jun 14 – Jul 15 |
| Snap beans | Sow outdoors | May 31 – Jul 14 |
| Sweet corn | Sow outdoors | May 31 – Jun 11 |
| Watermelon & cantaloupe | Sow outdoors | Jun 14 – Jul 15 |
| Okra | Sow outdoors | Jun 7 – Jun 30 |
| Peas | Sow outdoors (spring) | Apr 14 – May 30 |
| Potatoes | Plant outdoors (spring) | Apr 14 – Jun 14 |
| Onions | Start seeds indoors (spring) | Mar 3 – Mar 30 |
| Onions | Transplant outdoors (spring) | May 1 – May 30 |
| Broccoli | Start seeds indoors (spring) | Mar 27 – Apr 30 |
| Broccoli | Transplant outdoors (spring) | May 1 – May 30 |
| Broccoli | Start seeds indoors (fall) | Jun 1 – Jun 11 |
| Broccoli | Transplant outdoors (fall) | Jul 1 – Jul 12 |
| Cabbage | Start seeds indoors (spring) | Mar 17 – Apr 14 |
| Cabbage | Transplant outdoors (spring) | Apr 14 – May 15 |
| Cabbage | Start seeds indoors (fall) | May 22 – Jun 21 |
| Cabbage | Transplant outdoors (fall) | Jun 21 – Jul 22 |
| Leaf lettuce | Sow outdoors (spring) | Apr 14 – Jun 30 |
| Leaf lettuce | Sow outdoors (fall) | Jun 21 – Aug 7 |
| Spinach | Sow outdoors (spring) | Apr 7 – May 21 |
| Spinach | Sow outdoors (fall) | Jul 8 – Aug 12 |
| Radishes | Sow outdoors (spring) | Apr 14 – Jun 4 |
| Radishes | Sow outdoors (fall) | Jun 21 – Aug 22 |
| Kale | Sow outdoors (spring) | May 1 – May 21 |
| Kale | Sow outdoors (fall) | Jun 14 – Jul 22 |
| Carrots | Sow outdoors (spring) | May 15 – Jun 30 |
| Carrots | Sow outdoors (fall) | May 22 – Jul 7 |
| Garlic | Plant outdoors (fall) | Sep 21 – Oct 22 |
Where these dates come from
ZIP code 55603 is matched to the NOAA station Wolf Ridge Elc, MN, 3.4 km away, at 1,400 ft elevation (29 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Wolf Ridge Elc, MN (used) | 1,400 ft | May 15 | Oct 1 |
| Isabella 14W, MN | 1,740 ft | May 31 | Sep 15 |
| Two Harbors 7Nw, MN | 1,355 ft | May 27 | Sep 23 |
| Lutsen 3Nne, MN | 1,300 ft | May 26 | Sep 27 |
Frost dates near Finland
- Silver Bay, MN 55614 · last May 15, first Oct 1
- Beaver Bay, MN 55601 · last May 15, first Oct 1
- Schroeder, MN 55613 · last May 26, first Sep 27
- Tofte, MN 55615 · last May 22, first Oct 9
- Isabella, MN 55607 · last May 31, first Sep 15
- Brimson, MN 55602 · last —, first —
- Lutsen, MN 55612 · last May 26, first Sep 27
- Two Harbors, MN 55616 · last May 12, first Oct 6
Frequently asked questions
- When is the last frost in Finland, MN?
- For ZIP code 55603, the average last spring frost (32°F) is May 15, based on NOAA 1991-2020 climate normals for the Wolf Ridge Elc, MN weather station. There is a 1-in-10 chance of a frost after May 31.
- When is the first frost in Finland, MN?
- The average first fall frost (32°F) is October 1. There is a 1-in-10 chance of frost by September 17, so tender plants are at risk from that point on.
- How long is the growing season in 55603?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 137 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.