Frost dates for 50847Grant, IA
The average last spring frost in Grant is April 27 and the average first fall frost is October 12, giving a typical growing season of about 168 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 27
- Average first fall frost
- Oct 12
- Growing season
- 168 days
Safer after May 11 (1-in-10 risk)
Possible by Sep 26 (1-in-10 risk)
Last frost typically in 177 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 22 · May 6 · May 21 | Sep 20 · Oct 2 · Oct 16 | 149 days | 100% |
| Frost / freeze (32°F) | Apr 13 · Apr 27 · May 11 | Sep 26 · Oct 12 · Oct 26 | 168 days | 100% |
| Hard freeze (28°F) | Apr 2 · Apr 16 · May 1 | Oct 4 · Oct 23 · Nov 5 | 187 days | 100% |
Planting calendar for Grant
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 27 – Jun 2 |
| Tomatoes | Transplant outdoors | May 13 – Jun 22 |
| Peppers | Start seeds indoors | Mar 27 – Apr 27 |
| Peppers | Transplant outdoors | May 27 – Jun 27 |
| Eggplant | Start seeds indoors | Apr 13 – May 12 |
| Eggplant | Transplant outdoors | May 27 – Jun 27 |
| Cucumbers | Sow outdoors | May 27 – Jul 2 |
| Summer squash | Sow outdoors | May 13 – Jun 27 |
| Winter squash & pumpkins | Sow outdoors | May 27 – Jun 27 |
| Snap beans | Sow outdoors | May 13 – Jul 25 |
| Sweet corn | Sow outdoors | May 13 – Jun 22 |
| Watermelon & cantaloupe | Sow outdoors | May 27 – Jun 27 |
| Okra | Sow outdoors | May 20 – Jun 12 |
| Peas | Sow outdoors (spring) | Mar 27 – May 12 |
| Potatoes | Plant outdoors (spring) | Mar 27 – May 27 |
| Onions | Start seeds indoors (spring) | Feb 13 – Mar 12 |
| Onions | Transplant outdoors (spring) | Apr 13 – May 12 |
| Broccoli | Start seeds indoors (spring) | Mar 9 – Apr 12 |
| Broccoli | Transplant outdoors (spring) | Apr 13 – May 12 |
| Broccoli | Start seeds indoors (fall) | Jun 12 – Jun 22 |
| Broccoli | Transplant outdoors (fall) | Jul 12 – Jul 23 |
| Cabbage | Start seeds indoors (spring) | Feb 27 – Mar 27 |
| Cabbage | Transplant outdoors (spring) | Mar 27 – Apr 27 |
| Cabbage | Start seeds indoors (fall) | Jun 2 – Jul 2 |
| Cabbage | Transplant outdoors (fall) | Jul 2 – Aug 2 |
| Leaf lettuce | Sow outdoors (spring) | Mar 27 – Jun 12 |
| Leaf lettuce | Sow outdoors (fall) | Jul 2 – Aug 18 |
| Spinach | Sow outdoors (spring) | Mar 20 – May 3 |
| Spinach | Sow outdoors (fall) | Jul 19 – Aug 23 |
| Radishes | Sow outdoors (spring) | Mar 27 – May 17 |
| Radishes | Sow outdoors (fall) | Jul 2 – Sep 2 |
| Kale | Sow outdoors (spring) | Apr 13 – May 3 |
| Kale | Sow outdoors (fall) | Jun 25 – Aug 2 |
| Carrots | Sow outdoors (spring) | Apr 27 – Jun 12 |
| Carrots | Sow outdoors (fall) | Jun 2 – Jul 18 |
| Garlic | Plant outdoors (fall) | Oct 2 – Nov 2 |
Where these dates come from
ZIP code 50847 is matched to the NOAA station Corning, IA, 25.5 km away, at 1,190 ft elevation (48 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Corning, IA (used) | 1,190 ft | Apr 27 | Oct 12 |
| Red Oak, IA | 1,040 ft | Apr 24 | Oct 13 |
| Atlantic 1 Ne, IA | 1,152 ft | Apr 30 | Oct 2 |
| Oakland, IA | 1,260 ft | Apr 23 | Oct 14 |
Frost dates near Grant
- Elliott, IA 51532 · last Apr 24, first Oct 13
- Cumberland, IA 50843 · last Apr 30, first Oct 2
- Griswold, IA 51535 · last Apr 30, first Oct 2
- Carbon, IA 50839 · last Apr 27, first Oct 12
- Lewis, IA 51544 · last Apr 30, first Oct 2
- Red Oak, IA 51591 · last Apr 24, first Oct 13
- Stanton, IA 51573 · last Apr 24, first Oct 13
- Massena, IA 50853 · last Apr 30, first Oct 2
Frequently asked questions
- When is the last frost in Grant, IA?
- For ZIP code 50847, the average last spring frost (32°F) is April 27, based on NOAA 1991-2020 climate normals for the Corning, IA weather station. There is a 1-in-10 chance of a frost after May 11.
- When is the first frost in Grant, IA?
- The average first fall frost (32°F) is October 12. There is a 1-in-10 chance of frost by September 26, so tender plants are at risk from that point on.
- How long is the growing season in 50847?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 168 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.