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Will it freeze in Oak Brook in the next 7 nights?
No overnight lows at or below 32°F are forecast in Oak Brook during the next 7 nights in the available NWS frost forecast.
Tonight: forecast low 40°F. Above 36°F.
NWS forecast period: Thu, Nov 5, 6:00 PM CST to Fri, Nov 6, 6:00 AM CST.
2 of the next 7 nights are forecast at 36°F or colder, cold enough for frost on exposed plants.
- Tonight 40°F Above 36°F · Chance Rain Showers then Mostly Cloudy
- Fri, Nov 6 35°F Frost possible · Mostly Clear
- Sat, Nov 7 36°F Frost possible · Mostly Clear
- Sun, Nov 8 38°F Above 36°F · Mostly Clear
- Mon, Nov 9 44°F Above 36°F · Mostly Clear
- Tue, Nov 10 41°F Above 36°F · Partly Cloudy
- Wed, Nov 11 41°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 Oak Brook
The median first fall hard-freeze date (28°F) is October 26, from NOAA’s 1991–2020 Climate Normals at Lisle-Morton Arboretum. 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 25 · May 9 · May 25 | Sep 22 · Oct 6 · Oct 18 | 148 days |
| 32°F freeze | Apr 14 · Apr 28 · May 14 | Oct 1 · Oct 16 · Oct 29 | 169 days |
| 28°F hard freeze | Apr 2 · Apr 16 · May 4 | Oct 12 · Oct 26 · Nov 8 | 190 days |
Average high temperature by month
1991–2020 normals at Lisle-Morton Arboretum
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 Oak Brook, IL come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Lisle-Morton Arboretum (station USC00115097, elevation 680 ft), 6.4 mi from Oak Brook. 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 Oak Brook
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Clarendon Hills, IL | 2.5 mi | Apr 28 | Oct 16 |
| Hinsdale, IL | 2.5 mi | Apr 19 | Oct 22 |
| Westmont, IL | 3.1 mi | Apr 28 | Oct 16 |
| Westchester, IL | 3.1 mi | Apr 11 | Oct 31 |
| Hillside, IL | 3.1 mi | Apr 16 | Oct 28 |
| Western Springs, IL | 3.7 mi | Apr 19 | Oct 22 |
| Villa Park, IL | 3.7 mi | Apr 28 | Oct 16 |
| Lombard, IL | 4.3 mi | Apr 28 | Oct 16 |
| La Grange Park, IL | 4.3 mi | Apr 11 | Oct 31 |
| Elmhurst, IL | 4.3 mi | Apr 16 | Oct 28 |
Frequently asked questions
When is the last frost in Oak Brook?
On average, the last spring frost (32°F) in Oak Brook is around April 28. In about 1 year in 10 it comes after May 14, and in 9 years in 10 it comes after April 14.
When is the first frost in Oak Brook?
The first fall frost (32°F) usually arrives around October 16. There’s a 10% chance of a freeze by October 1 and a 90% chance by October 29.
Can it frost in Oak Brook 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 9.
What growing zone is Oak Brook?
Oak Brook is in USDA Plant Hardiness Zone 6a (average annual extreme minimum temperature −10 to −5°F), based on the 2023 USDA map for ZIP code 60523. See growing zones in Illinois.
More: all Illinois frost dates · Illinois growing zones · frost vs. freeze