Frost dates for 61468Ophiem, IL
The average last spring frost in Ophiem is April 22 and the average first fall frost is October 19, giving a typical growing season of about 181 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 22
- Average first fall frost
- Oct 19
- Growing season
- 181 days
Safer after May 6 (1-in-10 risk)
Possible by Oct 6 (1-in-10 risk)
Last frost typically in 174 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 19 · May 2 · May 16 | Sep 26 · Oct 9 · Oct 21 | 159 days | 100% |
| Frost / freeze (32°F) | Apr 7 · Apr 22 · May 6 | Oct 6 · Oct 19 · Oct 31 | 181 days | 100% |
| Hard freeze (28°F) | Mar 29 · Apr 11 · Apr 29 | Oct 16 · Oct 29 · Nov 10 | 200 days | 100% |
Planting calendar for Ophiem
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 22 – May 28 |
| Tomatoes | Transplant outdoors | May 8 – Jun 29 |
| Peppers | Start seeds indoors | Mar 22 – Apr 22 |
| Peppers | Transplant outdoors | May 22 – Jun 22 |
| Eggplant | Start seeds indoors | Apr 8 – May 7 |
| Eggplant | Transplant outdoors | May 22 – Jun 22 |
| Cucumbers | Sow outdoors | May 22 – Jul 9 |
| Summer squash | Sow outdoors | May 8 – Jun 22 |
| Winter squash & pumpkins | Sow outdoors | May 22 – Jun 22 |
| Snap beans | Sow outdoors | May 8 – Aug 1 |
| Sweet corn | Sow outdoors | May 8 – Jun 29 |
| Watermelon & cantaloupe | Sow outdoors | May 22 – Jun 22 |
| Okra | Sow outdoors | May 15 – Jun 7 |
| Peas | Sow outdoors (spring) | Mar 22 – May 7 |
| Potatoes | Plant outdoors (spring) | Mar 22 – May 22 |
| Onions | Start seeds indoors (spring) | Feb 8 – Mar 7 |
| Onions | Transplant outdoors (spring) | Apr 8 – May 7 |
| Broccoli | Start seeds indoors (spring) | Mar 4 – Apr 7 |
| Broccoli | Transplant outdoors (spring) | Apr 8 – May 7 |
| Broccoli | Start seeds indoors (fall) | Jun 19 – Jun 29 |
| Broccoli | Transplant outdoors (fall) | Jul 19 – Jul 30 |
| Cabbage | Start seeds indoors (spring) | Feb 22 – Mar 22 |
| Cabbage | Transplant outdoors (spring) | Mar 22 – Apr 22 |
| Cabbage | Start seeds indoors (fall) | Jun 9 – Jul 9 |
| Cabbage | Transplant outdoors (fall) | Jul 9 – Aug 9 |
| Leaf lettuce | Sow outdoors (spring) | Mar 22 – Jun 7 |
| Leaf lettuce | Sow outdoors (fall) | Jul 9 – Aug 25 |
| Spinach | Sow outdoors (spring) | Mar 15 – Apr 28 |
| Spinach | Sow outdoors (fall) | Jul 26 – Aug 30 |
| Radishes | Sow outdoors (spring) | Mar 22 – May 12 |
| Radishes | Sow outdoors (fall) | Jul 9 – Sep 9 |
| Kale | Sow outdoors (spring) | Apr 8 – Apr 28 |
| Kale | Sow outdoors (fall) | Jul 2 – Aug 9 |
| Carrots | Sow outdoors (spring) | Apr 22 – Jun 7 |
| Carrots | Sow outdoors (fall) | Jun 9 – Jul 25 |
| Garlic | Plant outdoors (fall) | Oct 9 – Nov 9 |
Where these dates come from
ZIP code 61468 is matched to the NOAA station Aledo, IL, 30.5 km away, at 730 ft elevation (11 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Aledo, IL (used) | 730 ft | Apr 22 | Oct 19 |
| Altona, IL | 765 ft | Apr 28 | Oct 12 |
| Moline Quad City Intl Ap, IL | 592 ft | Apr 24 | Oct 18 |
| Geneseo, IL | 639 ft | Apr 20 | Oct 20 |
Frost dates near Ophiem
- Lynn Center, IL 61262 · last Apr 20, first Oct 20
- Alpha, IL 61413 · last Apr 20, first Oct 19
- New Windsor, IL 61465 · last Apr 22, first Oct 19
- Andover, IL 61233 · last Apr 20, first Oct 20
- Sherrard, IL 61281 · last Apr 22, first Oct 19
- Woodhull, IL 61490 · last Apr 26, first Oct 12
- Orion, IL 61273 · last Apr 24, first Oct 18
- Rio, IL 61472 · last Apr 20, first Oct 19
Frequently asked questions
- When is the last frost in Ophiem, IL?
- For ZIP code 61468, the average last spring frost (32°F) is April 22, based on NOAA 1991-2020 climate normals for the Aledo, IL weather station. There is a 1-in-10 chance of a frost after May 6.
- When is the first frost in Ophiem, IL?
- The average first fall frost (32°F) is October 19. There is a 1-in-10 chance of frost by October 6, so tender plants are at risk from that point on.
- How long is the growing season in 61468?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 181 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.