Frost dates for 60051Mchenry, IL
The average last spring frost in Mchenry is May 1 and the average first fall frost is October 11, giving a typical growing season of about 162 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 1
- Average first fall frost
- Oct 11
- Growing season
- 162 days
Safer after May 19 (1-in-10 risk)
Possible by Sep 27 (1-in-10 risk)
Last frost typically in 182 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 28 · May 12 · May 28 | Sep 19 · Oct 1 · Oct 14 | 141 days | 100% |
| Frost / freeze (32°F) | Apr 16 · May 1 · May 19 | Sep 27 · Oct 11 · Oct 24 | 162 days | 100% |
| Hard freeze (28°F) | Apr 5 · Apr 19 · May 6 | Oct 7 · Oct 22 · Nov 4 | 185 days | 100% |
Planting calendar for Mchenry
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 21 |
| 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 – Jul 1 |
| Summer squash | Sow outdoors | May 17 – Jul 1 |
| Winter squash & pumpkins | Sow outdoors | May 31 – Jul 1 |
| Snap beans | Sow outdoors | May 17 – Jul 24 |
| Sweet corn | Sow outdoors | May 17 – Jun 21 |
| 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 11 – Jun 21 |
| Broccoli | Transplant outdoors (fall) | Jul 11 – Jul 22 |
| Cabbage | Start seeds indoors (spring) | Mar 3 – Mar 31 |
| Cabbage | Transplant outdoors (spring) | Mar 31 – May 1 |
| Cabbage | Start seeds indoors (fall) | Jun 1 – Jul 1 |
| Cabbage | Transplant outdoors (fall) | Jul 1 – Aug 1 |
| Leaf lettuce | Sow outdoors (spring) | Mar 31 – Jun 16 |
| Leaf lettuce | Sow outdoors (fall) | Jul 1 – Aug 17 |
| Spinach | Sow outdoors (spring) | Mar 24 – May 7 |
| Spinach | Sow outdoors (fall) | Jul 18 – Aug 22 |
| Radishes | Sow outdoors (spring) | Mar 31 – May 21 |
| Radishes | Sow outdoors (fall) | Jul 1 – Sep 1 |
| Kale | Sow outdoors (spring) | Apr 17 – May 7 |
| Kale | Sow outdoors (fall) | Jun 24 – Aug 1 |
| Carrots | Sow outdoors (spring) | May 1 – Jun 16 |
| Carrots | Sow outdoors (fall) | Jun 1 – Jul 17 |
| Garlic | Plant outdoors (fall) | Oct 1 – Nov 1 |
Where these dates come from
ZIP code 60051 is matched to the NOAA station Mc Henry -Wg Stratton L&D, IL, 5.4 km away, at 736 ft elevation (22 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Mc Henry -Wg Stratton L&D, IL (used) | 736 ft | May 1 | Oct 11 |
| Lake Villa 2Ne, IL | 840 ft | Apr 24 | Oct 23 |
| Mundelein 4 Wsw, IL | 840 ft | Apr 29 | Oct 20 |
| Crystal Lake 4Nw, IL | 940 ft | Apr 25 | Oct 22 |
Frost dates near Mchenry
- Ingleside, IL 60041 · last May 1, first Oct 11
- Mchenry, IL 60050 · last May 1, first Oct 11
- Fox Lake, IL 60020 · last Apr 24, first Oct 23
- Ringwood, IL 60072 · last May 1, first Oct 11
- Island Lake, IL 60042 · last May 1, first Oct 11
- Spring Grove, IL 60081 · last Apr 23, first Oct 21
- Wonder Lake, IL 60097 · last May 1, first Oct 11
- Round Lake, IL 60073 · last Apr 24, first Oct 23
Frequently asked questions
- When is the last frost in Mchenry, IL?
- For ZIP code 60051, the average last spring frost (32°F) is May 1, based on NOAA 1991-2020 climate normals for the Mc Henry -Wg Stratton L&D, IL weather station. There is a 1-in-10 chance of a frost after May 19.
- When is the first frost in Mchenry, IL?
- The average first fall frost (32°F) is October 11. There is a 1-in-10 chance of frost by September 27, so tender plants are at risk from that point on.
- How long is the growing season in 60051?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 162 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.