Frost dates for 54020Osceola, WI
The average last spring frost in Osceola is May 4 and the average first fall frost is October 8, giving a typical growing season of about 156 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 4
- Average first fall frost
- Oct 8
- Growing season
- 156 days
Safer after May 18 (1-in-10 risk)
Possible by Sep 24 (1-in-10 risk)
Last frost typically in 184 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) | Apr 30 · May 14 · May 27 | Sep 15 · Sep 29 · Oct 12 | 137 days | 100% |
| Frost / freeze (32°F) | Apr 20 · May 4 · May 18 | Sep 24 · Oct 8 · Oct 23 | 156 days | 100% |
| Hard freeze (28°F) | Apr 9 · Apr 24 · May 8 | Oct 3 · Oct 20 · Nov 2 | 177 days | 100% |
Planting calendar for Osceola
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 3 – Jun 9 |
| Tomatoes | Transplant outdoors | May 20 – Jun 18 |
| Peppers | Start seeds indoors | Apr 3 – May 4 |
| Peppers | Transplant outdoors | Jun 3 – Jul 4 |
| Eggplant | Start seeds indoors | Apr 20 – May 19 |
| Eggplant | Transplant outdoors | Jun 3 – Jul 4 |
| Cucumbers | Sow outdoors | Jun 3 – Jun 28 |
| Summer squash | Sow outdoors | May 20 – Jul 4 |
| Winter squash & pumpkins | Sow outdoors | Jun 3 – Jul 4 |
| Snap beans | Sow outdoors | May 20 – Jul 21 |
| Sweet corn | Sow outdoors | May 20 – Jun 18 |
| Watermelon & cantaloupe | Sow outdoors | Jun 3 – Jul 4 |
| Okra | Sow outdoors | May 27 – Jun 19 |
| Peas | Sow outdoors (spring) | Apr 3 – May 19 |
| Potatoes | Plant outdoors (spring) | Apr 3 – Jun 3 |
| Onions | Start seeds indoors (spring) | Feb 20 – Mar 19 |
| Onions | Transplant outdoors (spring) | Apr 20 – May 19 |
| Broccoli | Start seeds indoors (spring) | Mar 16 – Apr 19 |
| Broccoli | Transplant outdoors (spring) | Apr 20 – May 19 |
| Broccoli | Start seeds indoors (fall) | Jun 8 – Jun 18 |
| Broccoli | Transplant outdoors (fall) | Jul 8 – Jul 19 |
| Cabbage | Start seeds indoors (spring) | Mar 6 – Apr 3 |
| Cabbage | Transplant outdoors (spring) | Apr 3 – May 4 |
| Cabbage | Start seeds indoors (fall) | May 29 – Jun 28 |
| Cabbage | Transplant outdoors (fall) | Jun 28 – Jul 29 |
| Leaf lettuce | Sow outdoors (spring) | Apr 3 – Jun 19 |
| Leaf lettuce | Sow outdoors (fall) | Jun 28 – Aug 14 |
| Spinach | Sow outdoors (spring) | Mar 27 – May 10 |
| Spinach | Sow outdoors (fall) | Jul 15 – Aug 19 |
| Radishes | Sow outdoors (spring) | Apr 3 – May 24 |
| Radishes | Sow outdoors (fall) | Jun 28 – Aug 29 |
| Kale | Sow outdoors (spring) | Apr 20 – May 10 |
| Kale | Sow outdoors (fall) | Jun 21 – Jul 29 |
| Carrots | Sow outdoors (spring) | May 4 – Jun 19 |
| Carrots | Sow outdoors (fall) | May 29 – Jul 14 |
| Garlic | Plant outdoors (fall) | Sep 28 – Oct 29 |
Where these dates come from
ZIP code 54020 is matched to the NOAA station St Croix Falls, WI, 10.7 km away, at 750 ft elevation (77 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| St Croix Falls, WI (used) | 750 ft | May 4 | Oct 8 |
| Forest Lake 5Ne, MN | 905 ft | May 3 | Oct 5 |
| Wild Rvr Sp, MN | 840 ft | May 19 | Sep 25 |
| Amery, WI | 1,070 ft | May 5 | Oct 4 |
Frost dates near Osceola
- Shafer, MN 55074 · last May 3, first Oct 5
- Dresser, WI 54009 · last May 5, first Oct 4
- Scandia, MN 55073 · last May 3, first Oct 5
- Lindstrom, MN 55045 · last May 3, first Oct 5
- Taylors Falls, MN 55084 · last May 19, first Sep 25
- Center City, MN 55012 · last May 19, first Sep 25
- Chisago City, MN 55013 · last May 3, first Oct 5
- Marine On Saint Croix, MN 55047 · last May 3, first Oct 5
Frequently asked questions
- When is the last frost in Osceola, WI?
- For ZIP code 54020, the average last spring frost (32°F) is May 4, based on NOAA 1991-2020 climate normals for the St Croix Falls, WI weather station. There is a 1-in-10 chance of a frost after May 18.
- When is the first frost in Osceola, WI?
- The average first fall frost (32°F) is October 8. There is a 1-in-10 chance of frost by September 24, so tender plants are at risk from that point on.
- How long is the growing season in 54020?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 156 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.