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Will it freeze in McHenry in the next 7 nights?
The earliest overnight low at or below 32°F in the available NWS frost forecast is Fri, Nov 6: 29°F (Fri, Nov 6, 6:00 PM CST to Sat, Nov 7, 6:00 AM CST).
Tonight: forecast low 36°F. Frost possible.
NWS forecast period: Thu, Nov 5, 6:00 PM CST to Fri, Nov 6, 6:00 AM CST.
4 of the next 7 nights are forecast at 36°F or colder, cold enough for frost on exposed plants.
- Tonight 36°F Frost possible · Areas Of Drizzle then Mostly Cloudy
- Fri, Nov 6 29°F Freeze · Partly Cloudy
- Sat, Nov 7 32°F Freeze · Partly Cloudy
- Sun, Nov 8 34°F Frost possible · Mostly Clear
- Mon, Nov 9 39°F Above 36°F · Mostly Clear
- Tue, Nov 10 37°F Above 36°F · Partly Cloudy
- Wed, Nov 11 37°F Above 36°F · Partly Cloudy
Overnight lows from the National Weather Service forecast for this location. This covers the available forecast window, not the first freeze of the whole season. Frost can form above 32°F on clear, calm nights.
Frost and freeze probabilities
Freeze dates shift from year to year. Spring percentages describe the chance of a freeze after the stated date; fall percentages describe the chance of a freeze by that date. The 10% spring date is the cautious one: a later freeze happens about 1 year in 10.
These dates describe historical probabilities, not this year’s forecast or the earliest and latest possible freezes. Different weather stations or probability thresholds can produce different published dates for the same city.
Average first hard freeze in McHenry
The median first fall hard-freeze date (28°F) is October 22, from NOAA’s 1991–2020 Climate Normals at Mc Henry -Wg Stratton L&d. This is the 50% probability date, not a forecast for this year.
| Temperature | Last spring date 90% · 50% · 10% chance of a later freeze | First fall date 10% · 50% · 90% chance of an earlier freeze | Season |
|---|---|---|---|
| 36°F frost possible | Apr 28 · May 12 · May 28 | Sep 19 · Oct 1 · Oct 14 | 141 days |
| 32°F freeze | Apr 16 · May 1 · May 19 | Sep 27 · Oct 11 · Oct 24 | 162 days |
| 28°F hard freeze | Apr 5 · Apr 19 · May 6 | Oct 7 · Oct 22 · Nov 4 | 185 days |
Average high temperature by month
1991–2020 normals at Mc Henry -Wg Stratton L&d
Average low temperature by month
Months with lows near or below freezing carry frost risk
Where these frost dates come from
The frost dates for McHenry, IL come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Mc Henry -Wg Stratton L&d (station USC00115493, elevation 736 ft), 2.7 mi from McHenry. Local conditions (valleys, hilltops, distance to water, city heat) can shift frost dates by days or weeks. The hardiness zone is from the 2023 USDA Plant Hardiness Zone Map (USDA ARS and Oregon State University PRISM). See our methodology.
Frost dates near McHenry
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Wonder Lake, IL | 3.7 mi | May 1 | Oct 11 |
| Johnsburg, IL | 3.7 mi | May 1 | Oct 11 |
| Lakemoor, IL | 4.3 mi | May 1 | Oct 11 |
| Island Lake, IL | 6.2 mi | May 1 | Oct 11 |
| Volo, IL | 6.8 mi | May 1 | Oct 11 |
| Crystal Lake, IL | 7.5 mi | Apr 25 | Oct 22 |
| Woodstock, IL | 7.5 mi | Apr 25 | Oct 22 |
| Spring Grove, IL | 8.1 mi | Apr 30 | Oct 13 |
| Fox Lake, IL | 8.7 mi | Apr 23 | Oct 21 |
| Cary, IL | 8.7 mi | May 1 | Oct 11 |
Frequently asked questions
When is the last frost in McHenry?
On average, the last spring frost (32°F) in McHenry is around May 1. In about 1 year in 10 it comes after May 19, and in 9 years in 10 it comes after April 16.
When is the first frost in McHenry?
The first fall frost (32°F) usually arrives around October 11. There’s a 10% chance of a freeze by September 27 and a 90% chance by October 24.
Can it frost in McHenry after the last frost date?
Yes. Frost can form on clear, calm nights even when the air stays above 32°F. Temperatures of 36°F or lower, cold enough for frost on exposed plants, have a 50% chance of occurring after May 12.
What growing zone is McHenry?
McHenry is in USDA Plant Hardiness Zone 5b (average annual extreme minimum temperature −15 to −10°F), based on the 2023 USDA map for ZIP code 60050. See growing zones in Illinois.
More: all Illinois frost dates · Illinois growing zones · UV index today in McHenry · frost vs. freeze