Frost dates for 61041Hanover, IL
The average last spring frost in Hanover is May 1 and the average first fall frost is October 9, giving a typical growing season of about 160 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 1
- Average first fall frost
- Oct 9
- Growing season
- 160 days
Safer after May 17 (1-in-10 risk)
Possible by Sep 25 (1-in-10 risk)
Last frost typically in 181 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 27 · May 11 · May 26 | Sep 17 · Sep 30 · Oct 12 | 141 days | 100% |
| Frost / freeze (32°F) | Apr 17 · May 1 · May 17 | Sep 25 · Oct 9 · Oct 23 | 160 days | 100% |
| Hard freeze (28°F) | Apr 5 · Apr 20 · May 6 | Oct 4 · Oct 19 · Nov 1 | 183 days | 100% |
Planting calendar for Hanover
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 31 – Jun 6 |
| Tomatoes | Transplant outdoors | May 17 – Jun 19 |
| Peppers | Start seeds indoors | Mar 31 – May 1 |
| Peppers | Transplant outdoors | May 31 – Jul 1 |
| Eggplant | Start seeds indoors | Apr 17 – May 16 |
| Eggplant | Transplant outdoors | May 31 – Jul 1 |
| Cucumbers | Sow outdoors | May 31 – Jun 29 |
| Summer squash | Sow outdoors | May 17 – Jul 1 |
| Winter squash & pumpkins | Sow outdoors | May 31 – Jul 1 |
| Snap beans | Sow outdoors | May 17 – Jul 22 |
| Sweet corn | Sow outdoors | May 17 – Jun 19 |
| Watermelon & cantaloupe | Sow outdoors | May 31 – Jul 1 |
| Okra | Sow outdoors | May 24 – Jun 16 |
| Peas | Sow outdoors (spring) | Mar 31 – May 16 |
| Potatoes | Plant outdoors (spring) | Mar 31 – May 31 |
| Onions | Start seeds indoors (spring) | Feb 17 – Mar 16 |
| Onions | Transplant outdoors (spring) | Apr 17 – May 16 |
| Broccoli | Start seeds indoors (spring) | Mar 13 – Apr 16 |
| Broccoli | Transplant outdoors (spring) | Apr 17 – May 16 |
| Broccoli | Start seeds indoors (fall) | Jun 9 – Jun 19 |
| Broccoli | Transplant outdoors (fall) | Jul 9 – Jul 20 |
| Cabbage | Start seeds indoors (spring) | Mar 3 – Mar 31 |
| Cabbage | Transplant outdoors (spring) | Mar 31 – May 1 |
| Cabbage | Start seeds indoors (fall) | May 30 – Jun 29 |
| Cabbage | Transplant outdoors (fall) | Jun 29 – Jul 30 |
| Leaf lettuce | Sow outdoors (spring) | Mar 31 – Jun 16 |
| Leaf lettuce | Sow outdoors (fall) | Jun 29 – Aug 15 |
| Spinach | Sow outdoors (spring) | Mar 24 – May 7 |
| Spinach | Sow outdoors (fall) | Jul 16 – Aug 20 |
| Radishes | Sow outdoors (spring) | Mar 31 – May 21 |
| Radishes | Sow outdoors (fall) | Jun 29 – Aug 30 |
| Kale | Sow outdoors (spring) | Apr 17 – May 7 |
| Kale | Sow outdoors (fall) | Jun 22 – Jul 30 |
| Carrots | Sow outdoors (spring) | May 1 – Jun 16 |
| Carrots | Sow outdoors (fall) | May 30 – Jul 15 |
| Garlic | Plant outdoors (fall) | Sep 29 – Oct 30 |
Where these dates come from
ZIP code 61041 is matched to the NOAA station Elizabeth, IL, 8.2 km away, at 675 ft elevation (8 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Elizabeth, IL (used) | 675 ft | May 1 | Oct 9 |
| Bellevue L&D 12, IA | 603 ft | Apr 25 | Oct 16 |
| Galena, IL | 822 ft | Apr 26 | Oct 15 |
| Stockton 3 Nne, IL | 970 ft | Apr 27 | Oct 9 |
Frost dates near Hanover
- Elizabeth, IL 61028 · last May 1, first Oct 9
- Bellevue, IA 52031 · last Apr 25, first Oct 16
- Saint Donatus, IA 52071 · last Apr 25, first Oct 16
- Miles, IA 52064 · last Apr 25, first Oct 16
- Springbrook, IA 52075 · last Apr 25, first Oct 16
- Galena, IL 61036 · last Apr 25, first Oct 16
- Savanna, IL 61074 · last May 2, first Oct 7
- Sabula, IA 52070 · last May 2, first Oct 7
Frequently asked questions
- When is the last frost in Hanover, IL?
- For ZIP code 61041, the average last spring frost (32°F) is May 1, based on NOAA 1991-2020 climate normals for the Elizabeth, IL weather station. There is a 1-in-10 chance of a frost after May 17.
- When is the first frost in Hanover, IL?
- The average first fall frost (32°F) is October 9. There is a 1-in-10 chance of frost by September 25, so tender plants are at risk from that point on.
- How long is the growing season in 61041?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 160 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.