Frost dates for 56679South International Falls, MN
The average last spring frost in South International Falls is May 29 and the average first fall frost is September 13, giving a typical growing season of about 109 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 29
- Average first fall frost
- Sep 13
- Growing season
- 109 days
Safer after Jun 16 (1-in-10 risk)
Possible by Aug 30 (1-in-10 risk)
Last frost typically in 214 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) | — | — | 76 days | 100% |
| Frost / freeze (32°F) | May 13 · May 29 · Jun 16 | Aug 30 · Sep 13 · Sep 28 | 109 days | 100% |
| Hard freeze (28°F) | Apr 30 · May 14 · May 30 | Sep 9 · Sep 26 · Oct 9 | 133 days | 100% |
Planting calendar for South International Falls
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 28 – Jul 4 |
| Tomatoes | Transplant outdoors | Jun 14 – May 24 |
| Peppers | Start seeds indoors | Apr 28 – May 29 |
| Peppers | Transplant outdoors | Jun 28 – Jul 29 |
| Eggplant | Start seeds indoors | May 15 – Jun 13 |
| Eggplant | Transplant outdoors | Jun 28 – Jul 29 |
| Cucumbers | Sow outdoors | Jun 28 – Jun 3 |
| Summer squash | Sow outdoors | Jun 14 – Jul 29 |
| Winter squash & pumpkins | Sow outdoors | Jun 28 – Jul 29 |
| Snap beans | Sow outdoors | Jun 14 – Jun 26 |
| Sweet corn | Sow outdoors | Jun 14 – May 24 |
| Watermelon & cantaloupe | Sow outdoors | Jun 28 – Jul 29 |
| Okra | Sow outdoors | Jun 21 – Jul 14 |
| Peas | Sow outdoors (spring) | Apr 28 – Jun 13 |
| Potatoes | Plant outdoors (spring) | Apr 28 – Jun 28 |
| Onions | Start seeds indoors (spring) | Mar 17 – Apr 13 |
| Onions | Transplant outdoors (spring) | May 15 – Jun 13 |
| Broccoli | Start seeds indoors (spring) | Apr 10 – May 14 |
| Broccoli | Transplant outdoors (spring) | May 15 – Jun 13 |
| Broccoli | Start seeds indoors (fall) | May 14 – May 24 |
| Broccoli | Transplant outdoors (fall) | Jun 13 – Jun 24 |
| Cabbage | Start seeds indoors (spring) | Mar 31 – Apr 28 |
| Cabbage | Transplant outdoors (spring) | Apr 28 – May 29 |
| Cabbage | Start seeds indoors (fall) | May 4 – Jun 3 |
| Cabbage | Transplant outdoors (fall) | Jun 3 – Jul 4 |
| Leaf lettuce | Sow outdoors (spring) | Apr 28 – Jul 14 |
| Leaf lettuce | Sow outdoors (fall) | Jun 3 – Jul 20 |
| Spinach | Sow outdoors (spring) | Apr 21 – Jun 4 |
| Spinach | Sow outdoors (fall) | Jun 20 – Jul 25 |
| Radishes | Sow outdoors (spring) | Apr 28 – Jun 18 |
| Radishes | Sow outdoors (fall) | Jun 3 – Aug 4 |
| Kale | Sow outdoors (spring) | May 15 – Jun 4 |
| Kale | Sow outdoors (fall) | May 27 – Jul 4 |
| Carrots | Sow outdoors (spring) | May 29 – Jul 14 |
| Carrots | Sow outdoors (fall) | May 4 – Jun 19 |
| Garlic | Plant outdoors (fall) | Sep 3 – Oct 4 |
Where these dates come from
ZIP code 56679 is matched to the NOAA station Intl Falls Intl Ap, MN, 2.8 km away, at 1,183 ft elevation (35 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Intl Falls Intl Ap, MN (used) | 1,183 ft | May 29 | Sep 13 |
| Kabetogama, MN | 1,200 ft | May 28 | Sep 16 |
| Littlefork 10 Sw, MN | 1,200 ft | May 23 | Sep 21 |
| Big Falls, MN | 1,220 ft | May 24 | Sep 20 |
Frost dates near South International Falls
- International Falls, MN 56649 · last May 29, first Sep 13
- Ranier, MN 56668 · last May 29, first Sep 13
- Littlefork, MN 56653 · last May 23, first Sep 21
- Loman, MN 56654 · last May 23, first Sep 21
- Kabetogama, MN 56669 · last May 24, first Sep 20
- Big Falls, MN 56627 · last May 24, first Sep 20
- Birchdale, MN 56629 · last May 14, first Sep 26
- Nett Lake, MN 55772 · last May 28, first Sep 16
Frequently asked questions
- When is the last frost in South International Falls, MN?
- For ZIP code 56679, the average last spring frost (32°F) is May 29, based on NOAA 1991-2020 climate normals for the Intl Falls Intl Ap, MN weather station. There is a 1-in-10 chance of a frost after June 16.
- When is the first frost in South International Falls, MN?
- The average first fall frost (32°F) is September 13. There is a 1-in-10 chance of frost by August 30, so tender plants are at risk from that point on.
- How long is the growing season in 56679?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 109 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.