Frost dates for 56584Twin Valley, MN
The average last spring frost in Twin Valley is May 7 and the average first fall frost is September 28, giving a typical growing season of about 143 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 7
- Average first fall frost
- Sep 28
- Growing season
- 143 days
Safer after May 24 (1-in-10 risk)
Possible by Sep 15 (1-in-10 risk)
Last frost typically in 192 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 5 · May 19 · Jun 5 | Sep 3 · Sep 19 · Oct 1 | 121 days | 100% |
| Frost / freeze (32°F) | Apr 27 · May 7 · May 24 | Sep 15 · Sep 28 · Oct 13 | 143 days | 100% |
| Hard freeze (28°F) | Apr 15 · Apr 29 · May 12 | Sep 23 · Oct 8 · Oct 25 | 162 days | 100% |
Planting calendar for Twin Valley
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 6 – Jun 12 |
| Tomatoes | Transplant outdoors | May 23 – Jun 8 |
| Peppers | Start seeds indoors | Apr 6 – May 7 |
| Peppers | Transplant outdoors | Jun 6 – Jul 7 |
| Eggplant | Start seeds indoors | Apr 23 – May 22 |
| Eggplant | Transplant outdoors | Jun 6 – Jul 7 |
| Cucumbers | Sow outdoors | Jun 6 – Jun 18 |
| Summer squash | Sow outdoors | May 23 – Jul 7 |
| Winter squash & pumpkins | Sow outdoors | Jun 6 – Jul 7 |
| Snap beans | Sow outdoors | May 23 – Jul 11 |
| Sweet corn | Sow outdoors | May 23 – Jun 8 |
| Watermelon & cantaloupe | Sow outdoors | Jun 6 – Jul 7 |
| Okra | Sow outdoors | May 30 – Jun 22 |
| Peas | Sow outdoors (spring) | Apr 6 – May 22 |
| Potatoes | Plant outdoors (spring) | Apr 6 – Jun 6 |
| Onions | Start seeds indoors (spring) | Feb 23 – Mar 22 |
| Onions | Transplant outdoors (spring) | Apr 23 – May 22 |
| Broccoli | Start seeds indoors (spring) | Mar 19 – Apr 22 |
| Broccoli | Transplant outdoors (spring) | Apr 23 – May 22 |
| Broccoli | Start seeds indoors (fall) | May 29 – Jun 8 |
| Broccoli | Transplant outdoors (fall) | Jun 28 – Jul 9 |
| Cabbage | Start seeds indoors (spring) | Mar 9 – Apr 6 |
| Cabbage | Transplant outdoors (spring) | Apr 6 – May 7 |
| Cabbage | Start seeds indoors (fall) | May 19 – Jun 18 |
| Cabbage | Transplant outdoors (fall) | Jun 18 – Jul 19 |
| Leaf lettuce | Sow outdoors (spring) | Apr 6 – Jun 22 |
| Leaf lettuce | Sow outdoors (fall) | Jun 18 – Aug 4 |
| Spinach | Sow outdoors (spring) | Mar 30 – May 13 |
| Spinach | Sow outdoors (fall) | Jul 5 – Aug 9 |
| Radishes | Sow outdoors (spring) | Apr 6 – May 27 |
| Radishes | Sow outdoors (fall) | Jun 18 – Aug 19 |
| Kale | Sow outdoors (spring) | Apr 23 – May 13 |
| Kale | Sow outdoors (fall) | Jun 11 – Jul 19 |
| Carrots | Sow outdoors (spring) | May 7 – Jun 22 |
| Carrots | Sow outdoors (fall) | May 19 – Jul 4 |
| Garlic | Plant outdoors (fall) | Sep 18 – Oct 19 |
Where these dates come from
ZIP code 56584 is matched to the NOAA station Mahnomen, MN, 22.2 km away, at 1,212 ft elevation (106 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Mahnomen, MN (used) | 1,212 ft | May 7 | Sep 28 |
| Ada, MN | 907 ft | May 11 | Sep 27 |
| Georgetown 1 E, MN | 885 ft | May 9 | Oct 1 |
| Fosston 1 E, MN | 1,300 ft | May 15 | Sep 26 |
Frost dates near Twin Valley
- Gary, MN 56545 · last May 7, first Sep 28
- Flom, MN 56541 · last May 7, first Sep 28
- Ulen, MN 56585 · last May 7, first Sep 28
- Borup, MN 56519 · last May 11, first Sep 27
- Ada, MN 56510 · last May 11, first Sep 27
- Waubun, MN 56589 · last May 7, first Sep 28
- Hitterdal, MN 56552 · last May 7, first Sep 28
- Felton, MN 56536 · last May 9, first Oct 1
Frequently asked questions
- When is the last frost in Twin Valley, MN?
- For ZIP code 56584, the average last spring frost (32°F) is May 7, based on NOAA 1991-2020 climate normals for the Mahnomen, MN weather station. There is a 1-in-10 chance of a frost after May 24.
- When is the first frost in Twin Valley, MN?
- The average first fall frost (32°F) is September 28. There is a 1-in-10 chance of frost by September 15, so tender plants are at risk from that point on.
- How long is the growing season in 56584?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 143 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.