Frost dates for 56686Williams, MN
The average last spring frost in Williams is May 15 and the average first fall frost is September 26, giving a typical growing season of about 132 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 15
- Average first fall frost
- Sep 26
- Growing season
- 132 days
Safer after May 31 (1-in-10 risk)
Possible by Sep 9 (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 13 · May 27 · Jun 9 | Aug 31 · Sep 15 · Sep 28 | 111 days | 100% |
| Frost / freeze (32°F) | May 3 · May 15 · May 31 | Sep 9 · Sep 26 · Oct 9 | 132 days | 100% |
| Hard freeze (28°F) | Apr 21 · May 4 · May 20 | Sep 22 · Oct 6 · Oct 22 | 153 days | 100% |
Planting calendar for Williams
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 6 |
| 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 16 |
| Summer squash | Sow outdoors | May 31 – Jul 15 |
| Winter squash & pumpkins | Sow outdoors | Jun 14 – Jul 15 |
| Snap beans | Sow outdoors | May 31 – Jul 9 |
| Sweet corn | Sow outdoors | May 31 – Jun 6 |
| 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) | May 27 – Jun 6 |
| Broccoli | Transplant outdoors (fall) | Jun 26 – Jul 7 |
| Cabbage | Start seeds indoors (spring) | Mar 17 – Apr 14 |
| Cabbage | Transplant outdoors (spring) | Apr 14 – May 15 |
| Cabbage | Start seeds indoors (fall) | May 17 – Jun 16 |
| Cabbage | Transplant outdoors (fall) | Jun 16 – Jul 17 |
| Leaf lettuce | Sow outdoors (spring) | Apr 14 – Jun 30 |
| Leaf lettuce | Sow outdoors (fall) | Jun 16 – Aug 2 |
| Spinach | Sow outdoors (spring) | Apr 7 – May 21 |
| Spinach | Sow outdoors (fall) | Jul 3 – Aug 7 |
| Radishes | Sow outdoors (spring) | Apr 14 – Jun 4 |
| Radishes | Sow outdoors (fall) | Jun 16 – Aug 17 |
| Kale | Sow outdoors (spring) | May 1 – May 21 |
| Kale | Sow outdoors (fall) | Jun 9 – Jul 17 |
| Carrots | Sow outdoors (spring) | May 15 – Jun 30 |
| Carrots | Sow outdoors (fall) | May 17 – Jul 2 |
| Garlic | Plant outdoors (fall) | Sep 16 – Oct 17 |
Where these dates come from
ZIP code 56686 is matched to the NOAA station Baudette Intl Ap, MN, 27.7 km away, at 1,082 ft elevation (33 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Baudette Intl Ap, MN (used) | 1,082 ft | May 15 | Sep 26 |
| Camp Norris Dnr, MN | 1,289 ft | May 25 | Sep 22 |
| Baudette, MN | 1,094 ft | May 14 | Sep 26 |
| Warroad, MN | 1,073 ft | May 16 | Sep 24 |
Frost dates near Williams
- Roosevelt, MN 56673 · last May 16, first Sep 24
- Swift, MN 56682 · last May 16, first Sep 24
- Baudette, MN 56623 · last May 14, first Sep 26
- Warroad, MN 56763 · last May 16, first Sep 24
- Salol, MN 56756 · last May 16, first Sep 24
- Oak Island, MN 56741 · last May 16, first Sep 24
- Wannaska, MN 56761 · last May 16, first Sep 24
- Roseau, MN 56751 · last May 16, first Sep 24
Frequently asked questions
- When is the last frost in Williams, MN?
- For ZIP code 56686, the average last spring frost (32°F) is May 15, based on NOAA 1991-2020 climate normals for the Baudette Intl Ap, MN weather station. There is a 1-in-10 chance of a frost after May 31.
- When is the first frost in Williams, MN?
- The average first fall frost (32°F) is September 26. There is a 1-in-10 chance of frost by September 9, so tender plants are at risk from that point on.
- How long is the growing season in 56686?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 132 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.