Frost dates for 52079Zwingle, IA
The average last spring frost in Zwingle is April 28 and the average first fall frost is October 11, giving a typical growing season of about 165 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 28
- Average first fall frost
- Oct 11
- Growing season
- 165 days
Safer after May 12 (1-in-10 risk)
Possible by Sep 28 (1-in-10 risk)
Last frost typically in 178 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 23 · May 7 · May 21 | Sep 20 · Oct 2 · Oct 14 | 146 days | 100% |
| Frost / freeze (32°F) | Apr 13 · Apr 28 · May 12 | Sep 28 · Oct 11 · Oct 23 | 165 days | 100% |
| Hard freeze (28°F) | Apr 2 · Apr 17 · May 3 | Oct 8 · Oct 21 · Nov 2 | 187 days | 100% |
Planting calendar for Zwingle
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 28 – Jun 3 |
| Tomatoes | Transplant outdoors | May 14 – Jun 21 |
| Peppers | Start seeds indoors | Mar 28 – Apr 28 |
| Peppers | Transplant outdoors | May 28 – Jun 28 |
| Eggplant | Start seeds indoors | Apr 14 – May 13 |
| Eggplant | Transplant outdoors | May 28 – Jun 28 |
| Cucumbers | Sow outdoors | May 28 – Jul 1 |
| Summer squash | Sow outdoors | May 14 – Jun 28 |
| Winter squash & pumpkins | Sow outdoors | May 28 – Jun 28 |
| Snap beans | Sow outdoors | May 14 – Jul 24 |
| Sweet corn | Sow outdoors | May 14 – Jun 21 |
| Watermelon & cantaloupe | Sow outdoors | May 28 – Jun 28 |
| Okra | Sow outdoors | May 21 – Jun 13 |
| Peas | Sow outdoors (spring) | Mar 28 – May 13 |
| Potatoes | Plant outdoors (spring) | Mar 28 – May 28 |
| Onions | Start seeds indoors (spring) | Feb 14 – Mar 13 |
| Onions | Transplant outdoors (spring) | Apr 14 – May 13 |
| Broccoli | Start seeds indoors (spring) | Mar 10 – Apr 13 |
| Broccoli | Transplant outdoors (spring) | Apr 14 – May 13 |
| Broccoli | Start seeds indoors (fall) | Jun 11 – Jun 21 |
| Broccoli | Transplant outdoors (fall) | Jul 11 – Jul 22 |
| Cabbage | Start seeds indoors (spring) | Feb 28 – Mar 28 |
| Cabbage | Transplant outdoors (spring) | Mar 28 – Apr 28 |
| Cabbage | Start seeds indoors (fall) | Jun 1 – Jul 1 |
| Cabbage | Transplant outdoors (fall) | Jul 1 – Aug 1 |
| Leaf lettuce | Sow outdoors (spring) | Mar 28 – Jun 13 |
| Leaf lettuce | Sow outdoors (fall) | Jul 1 – Aug 17 |
| Spinach | Sow outdoors (spring) | Mar 21 – May 4 |
| Spinach | Sow outdoors (fall) | Jul 18 – Aug 22 |
| Radishes | Sow outdoors (spring) | Mar 28 – May 18 |
| Radishes | Sow outdoors (fall) | Jul 1 – Sep 1 |
| Kale | Sow outdoors (spring) | Apr 14 – May 4 |
| Kale | Sow outdoors (fall) | Jun 24 – Aug 1 |
| Carrots | Sow outdoors (spring) | Apr 28 – Jun 13 |
| Carrots | Sow outdoors (fall) | Jun 1 – Jul 17 |
| Garlic | Plant outdoors (fall) | Oct 1 – Nov 1 |
Where these dates come from
ZIP code 52079 is matched to the NOAA station Dubuque Rgnl Ap, IA, 13.9 km away, at 1,056 ft elevation (118 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Dubuque Rgnl Ap, IA (used) | 1,056 ft | Apr 28 | Oct 11 |
| Cascade, IA | 814 ft | Apr 28 | Oct 10 |
| Maquoketa, IA | 668 ft | Apr 25 | Oct 14 |
| Bellevue L&D 12, IA | 603 ft | Apr 25 | Oct 16 |
Frost dates near Zwingle
- Bernard, IA 52032 · last Apr 28, first Oct 10
- La Motte, IA 52054 · last Apr 28, first Oct 11
- Andrew, IA 52030 · last Apr 25, first Oct 14
- Peosta, IA 52068 · last Apr 28, first Oct 11
- Dubuque, IA 52003 · last Apr 19, first Oct 21
- Cascade, IA 52033 · last Apr 28, first Oct 10
- Saint Donatus, IA 52071 · last Apr 25, first Oct 16
- Maquoketa, IA 52060 · last Apr 25, first Oct 14
Frequently asked questions
- When is the last frost in Zwingle, IA?
- For ZIP code 52079, the average last spring frost (32°F) is April 28, based on NOAA 1991-2020 climate normals for the Dubuque Rgnl Ap, IA weather station. There is a 1-in-10 chance of a frost after May 12.
- When is the first frost in Zwingle, IA?
- The average first fall frost (32°F) is October 11. 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 52079?
- 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.