Frost dates for 62993Unity, IL
The average last spring frost in Unity is April 2 and the average first fall frost is October 31, giving a typical growing season of about 211 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 2
- Average first fall frost
- Oct 31
- Growing season
- 211 days
Safer after Apr 17 (1-in-10 risk)
Possible by Oct 18 (1-in-10 risk)
First frost typically in 0 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) | Mar 31 · Apr 12 · Apr 28 | Oct 8 · Oct 20 · Nov 1 | 190 days | 100% |
| Frost / freeze (32°F) | Mar 19 · Apr 2 · Apr 17 | Oct 18 · Oct 31 · Nov 13 | 211 days | 100% |
| Hard freeze (28°F) | Mar 7 · Mar 24 · Apr 8 | Oct 29 · Nov 10 · Nov 28 | 230 days | 100% |
Planting calendar for Unity
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 2 – May 8 |
| Tomatoes | Transplant outdoors | Apr 18 – Jul 11 |
| Peppers | Start seeds indoors | Mar 2 – Apr 2 |
| Peppers | Transplant outdoors | May 2 – Jun 2 |
| Eggplant | Start seeds indoors | Mar 19 – Apr 17 |
| Eggplant | Transplant outdoors | May 2 – Jun 2 |
| Cucumbers | Sow outdoors | May 2 – Jul 21 |
| Summer squash | Sow outdoors | Apr 18 – Jun 2 |
| Winter squash & pumpkins | Sow outdoors | May 2 – Jun 2 |
| Snap beans | Sow outdoors | Apr 18 – Aug 13 |
| Sweet corn | Sow outdoors | Apr 18 – Jul 11 |
| Watermelon & cantaloupe | Sow outdoors | May 2 – Jun 2 |
| Okra | Sow outdoors | Apr 25 – May 18 |
| Peas | Sow outdoors (spring) | Mar 2 – Apr 17 |
| Potatoes | Plant outdoors (spring) | Mar 2 – May 2 |
| Onions | Start seeds indoors (spring) | Jan 19 – Feb 15 |
| Onions | Transplant outdoors (spring) | Mar 19 – Apr 17 |
| Broccoli | Start seeds indoors (spring) | Feb 12 – Mar 18 |
| Broccoli | Transplant outdoors (spring) | Mar 19 – Apr 17 |
| Broccoli | Start seeds indoors (fall) | Jul 1 – Jul 11 |
| Broccoli | Transplant outdoors (fall) | Jul 31 – Aug 11 |
| Cabbage | Start seeds indoors (spring) | Feb 2 – Mar 2 |
| Cabbage | Transplant outdoors (spring) | Mar 2 – Apr 2 |
| Cabbage | Start seeds indoors (fall) | Jun 21 – Jul 21 |
| Cabbage | Transplant outdoors (fall) | Jul 21 – Aug 21 |
| Leaf lettuce | Sow outdoors (spring) | Mar 2 – May 18 |
| Leaf lettuce | Sow outdoors (fall) | Jul 21 – Sep 6 |
| Spinach | Sow outdoors (spring) | Feb 23 – Apr 8 |
| Spinach | Sow outdoors (fall) | Aug 7 – Sep 11 |
| Radishes | Sow outdoors (spring) | Mar 2 – Apr 22 |
| Radishes | Sow outdoors (fall) | Jul 21 – Sep 21 |
| Kale | Sow outdoors (spring) | Mar 19 – Apr 8 |
| Kale | Sow outdoors (fall) | Jul 14 – Aug 21 |
| Carrots | Sow outdoors (spring) | Apr 2 – May 18 |
| Carrots | Sow outdoors (fall) | Jun 21 – Aug 6 |
| Garlic | Plant outdoors (fall) | Oct 21 – Nov 21 |
Where these dates come from
ZIP code 62993 is matched to the NOAA station Cairo 3N, IL, 17.5 km away, at 313 ft elevation (15 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Cairo 3N, IL (used) | 313 ft | Apr 2 | Oct 31 |
| Cape Girardeau Muni Ap, MO | 336 ft | Apr 5 | Oct 25 |
| Grand Chain Dam 53, IL | 385 ft | Apr 3 | Nov 5 |
| Anna 2 Nne, IL | 640 ft | Apr 8 | Oct 29 |
Frost dates near Unity
- Olive Branch, IL 62969 · last Apr 5, first Oct 25
- Miller City, IL 62962 · last Apr 2, first Oct 31
- Tamms, IL 62988 · last Apr 3, first Nov 5
- Commerce, MO 63742 · last Apr 5, first Oct 25
- Mounds, IL 62964 · last Apr 2, first Oct 31
- Villa Ridge, IL 62996 · last Apr 3, first Nov 5
- Pulaski, IL 62976 · last Apr 3, first Nov 5
- Thebes, IL 62990 · last Apr 5, first Oct 25
Frequently asked questions
- When is the last frost in Unity, IL?
- For ZIP code 62993, the average last spring frost (32°F) is April 2, based on NOAA 1991-2020 climate normals for the Cairo 3N, IL weather station. There is a 1-in-10 chance of a frost after April 17.
- When is the first frost in Unity, IL?
- The average first fall frost (32°F) is October 31. There is a 1-in-10 chance of frost by October 18, so tender plants are at risk from that point on.
- How long is the growing season in 62993?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 211 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.