Frost dates for 55974Spring Grove, MN
The average last spring frost in Spring Grove is April 29 and the average first fall frost is October 10, giving a typical growing season of about 165 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 29
- Average first fall frost
- Oct 10
- Growing season
- 165 days
Safer after May 11 (1-in-10 risk)
Possible by Sep 28 (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 26 · May 7 · May 20 | Sep 18 · Oct 1 · Oct 14 | 145 days | 100% |
| Frost / freeze (32°F) | Apr 14 · Apr 29 · May 11 | Sep 28 · Oct 10 · Oct 24 | 165 days | 100% |
| Hard freeze (28°F) | Apr 4 · Apr 18 · May 2 | Oct 9 · Oct 23 · Nov 4 | 187 days | 100% |
Planting calendar for Spring Grove
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 | Mar 29 – Jun 4 |
| Tomatoes | Transplant outdoors | May 15 – Jun 20 |
| Peppers | Start seeds indoors | Mar 29 – Apr 29 |
| Peppers | Transplant outdoors | May 29 – Jun 29 |
| Eggplant | Start seeds indoors | Apr 15 – May 14 |
| Eggplant | Transplant outdoors | May 29 – Jun 29 |
| Cucumbers | Sow outdoors | May 29 – Jun 30 |
| Summer squash | Sow outdoors | May 15 – Jun 29 |
| Winter squash & pumpkins | Sow outdoors | May 29 – Jun 29 |
| Snap beans | Sow outdoors | May 15 – Jul 23 |
| Sweet corn | Sow outdoors | May 15 – Jun 20 |
| Watermelon & cantaloupe | Sow outdoors | May 29 – Jun 29 |
| Okra | Sow outdoors | May 22 – Jun 14 |
| Peas | Sow outdoors (spring) | Mar 29 – May 14 |
| Potatoes | Plant outdoors (spring) | Mar 29 – May 29 |
| Onions | Start seeds indoors (spring) | Feb 15 – Mar 14 |
| Onions | Transplant outdoors (spring) | Apr 15 – May 14 |
| Broccoli | Start seeds indoors (spring) | Mar 11 – Apr 14 |
| Broccoli | Transplant outdoors (spring) | Apr 15 – May 14 |
| Broccoli | Start seeds indoors (fall) | Jun 10 – Jun 20 |
| Broccoli | Transplant outdoors (fall) | Jul 10 – Jul 21 |
| Cabbage | Start seeds indoors (spring) | Mar 1 – Mar 29 |
| Cabbage | Transplant outdoors (spring) | Mar 29 – Apr 29 |
| Cabbage | Start seeds indoors (fall) | May 31 – Jun 30 |
| Cabbage | Transplant outdoors (fall) | Jun 30 – Jul 31 |
| Leaf lettuce | Sow outdoors (spring) | Mar 29 – Jun 14 |
| Leaf lettuce | Sow outdoors (fall) | Jun 30 – Aug 16 |
| Spinach | Sow outdoors (spring) | Mar 22 – May 5 |
| Spinach | Sow outdoors (fall) | Jul 17 – Aug 21 |
| Radishes | Sow outdoors (spring) | Mar 29 – May 19 |
| Radishes | Sow outdoors (fall) | Jun 30 – Aug 31 |
| Kale | Sow outdoors (spring) | Apr 15 – May 5 |
| Kale | Sow outdoors (fall) | Jun 23 – Jul 31 |
| Carrots | Sow outdoors (spring) | Apr 29 – Jun 14 |
| Carrots | Sow outdoors (fall) | May 31 – Jul 16 |
| Garlic | Plant outdoors (fall) | Sep 30 – Oct 31 |
Where these dates come from
ZIP code 55974 is matched to the NOAA station Caledonia, MN, 13.2 km away, at 1,166 ft elevation (159 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Caledonia, MN (used) | 1,166 ft | Apr 29 | Oct 10 |
| Mabel, MN | 1,112 ft | May 10 | Sep 28 |
| Rushford, MN | 770 ft | May 8 | Oct 3 |
| Decorah, IA | 860 ft | May 3 | Oct 7 |
Frost dates near Spring Grove
- Mabel, MN 55954 · last May 10, first Sep 28
- Highlandville, IA 52149 · last Apr 29, first Oct 10
- Caledonia, MN 55921 · last Apr 29, first Oct 10
- Eitzen, MN 55931 · last Apr 29, first Oct 10
- Dorchester, IA 52140 · last Apr 22, first Oct 17
- Canton, MN 55922 · last May 8, first Oct 1
- Houston, MN 55943 · last May 8, first Oct 3
- New Albin, IA 52160 · last Apr 22, first Oct 17
Frequently asked questions
- When is the last frost in Spring Grove, MN?
- For ZIP code 55974, the average last spring frost (32°F) is April 29, based on NOAA 1991-2020 climate normals for the Caledonia, MN weather station. There is a 1-in-10 chance of a frost after May 11.
- When is the first frost in Spring Grove, MN?
- The average first fall frost (32°F) is October 10. There is a 1-in-10 chance of frost by September 28, so tender plants are at risk from that point on.
- How long is the growing season in 55974?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 165 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.