Frost dates for 52049Garnavillo, IA
The average last spring frost in Garnavillo is April 21 and the average first fall frost is October 18, giving a typical growing season of about 178 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 21
- Average first fall frost
- Oct 18
- Growing season
- 178 days
Safer after May 6 (1-in-10 risk)
Possible by Oct 4 (1-in-10 risk)
Last frost typically in 170 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 18 · May 3 · May 16 | Sep 24 · Oct 7 · Oct 21 | 156 days | 100% |
| Frost / freeze (32°F) | Apr 7 · Apr 21 · May 6 | Oct 4 · Oct 18 · Oct 30 | 178 days | 100% |
| Hard freeze (28°F) | Mar 30 · Apr 9 · Apr 26 | Oct 14 · Oct 27 · Nov 8 | 199 days | 100% |
Planting calendar for Garnavillo
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 21 – May 27 |
| Tomatoes | Transplant outdoors | May 7 – Jun 28 |
| Peppers | Start seeds indoors | Mar 21 – Apr 21 |
| Peppers | Transplant outdoors | May 21 – Jun 21 |
| Eggplant | Start seeds indoors | Apr 7 – May 6 |
| Eggplant | Transplant outdoors | May 21 – Jun 21 |
| Cucumbers | Sow outdoors | May 21 – Jul 8 |
| Summer squash | Sow outdoors | May 7 – Jun 21 |
| Winter squash & pumpkins | Sow outdoors | May 21 – Jun 21 |
| Snap beans | Sow outdoors | May 7 – Jul 31 |
| Sweet corn | Sow outdoors | May 7 – Jun 28 |
| Watermelon & cantaloupe | Sow outdoors | May 21 – Jun 21 |
| Okra | Sow outdoors | May 14 – Jun 6 |
| Peas | Sow outdoors (spring) | Mar 21 – May 6 |
| Potatoes | Plant outdoors (spring) | Mar 21 – May 21 |
| Onions | Start seeds indoors (spring) | Feb 7 – Mar 6 |
| Onions | Transplant outdoors (spring) | Apr 7 – May 6 |
| Broccoli | Start seeds indoors (spring) | Mar 3 – Apr 6 |
| Broccoli | Transplant outdoors (spring) | Apr 7 – May 6 |
| Broccoli | Start seeds indoors (fall) | Jun 18 – Jun 28 |
| Broccoli | Transplant outdoors (fall) | Jul 18 – Jul 29 |
| Cabbage | Start seeds indoors (spring) | Feb 21 – Mar 21 |
| Cabbage | Transplant outdoors (spring) | Mar 21 – Apr 21 |
| Cabbage | Start seeds indoors (fall) | Jun 8 – Jul 8 |
| Cabbage | Transplant outdoors (fall) | Jul 8 – Aug 8 |
| Leaf lettuce | Sow outdoors (spring) | Mar 21 – Jun 6 |
| Leaf lettuce | Sow outdoors (fall) | Jul 8 – Aug 24 |
| Spinach | Sow outdoors (spring) | Mar 14 – Apr 27 |
| Spinach | Sow outdoors (fall) | Jul 25 – Aug 29 |
| Radishes | Sow outdoors (spring) | Mar 21 – May 11 |
| Radishes | Sow outdoors (fall) | Jul 8 – Sep 8 |
| Kale | Sow outdoors (spring) | Apr 7 – Apr 27 |
| Kale | Sow outdoors (fall) | Jul 1 – Aug 8 |
| Carrots | Sow outdoors (spring) | Apr 21 – Jun 6 |
| Carrots | Sow outdoors (fall) | Jun 8 – Jul 24 |
| Garlic | Plant outdoors (fall) | Oct 8 – Nov 8 |
Where these dates come from
ZIP code 52049 is matched to the NOAA station Guttenberg L&D 10, IA, 14 km away, at 618 ft elevation (402 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Guttenberg L&D 10, IA (used) | 618 ft | Apr 21 | Oct 18 |
| Prairie Du Chien, WI | 658 ft | Apr 28 | Oct 12 |
| Elkader 6 Ssw, IA | 788 ft | May 8 | Oct 1 |
| Lancaster 4 Wsw, WI | 1,040 ft | Apr 27 | Oct 11 |
Frost dates near Garnavillo
- Bagley, WI 53801 · last Apr 28, first Oct 12
- Farmersburg, IA 52047 · last May 1, first Oct 3
- Saint Olaf, IA 52072 · last May 8, first Oct 1
- Garber, IA 52048 · last Apr 21, first Oct 18
- Guttenberg, IA 52052 · last Apr 21, first Oct 18
- Elkport, IA 52044 · last May 8, first Oct 1
- Elkader, IA 52043 · last May 8, first Oct 1
- Mc Gregor, IA 52157 · last Apr 28, first Oct 12
Frequently asked questions
- When is the last frost in Garnavillo, IA?
- For ZIP code 52049, the average last spring frost (32°F) is April 21, based on NOAA 1991-2020 climate normals for the Guttenberg L&D 10, IA weather station. There is a 1-in-10 chance of a frost after May 6.
- When is the first frost in Garnavillo, IA?
- The average first fall frost (32°F) is October 18. There is a 1-in-10 chance of frost by October 4, so tender plants are at risk from that point on.
- How long is the growing season in 52049?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 178 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.