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Will it freeze in Mount Prospect in the next 7 nights?
No overnight lows at or below 32°F are forecast in Mount Prospect during the next 7 nights in the available NWS frost forecast.
Tonight: forecast low 39°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 39°F Above 36°F · Chance Rain Showers then Mostly Cloudy
- Fri, Nov 6 34°F Frost possible · Partly Cloudy
- Sat, Nov 7 35°F Frost possible · Partly Cloudy
- Sun, Nov 8 37°F Above 36°F · Mostly Clear
- Mon, Nov 9 43°F Above 36°F · Mostly Clear
- Tue, Nov 10 40°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 Mount Prospect
The median first fall hard-freeze date (28°F) is November 7, from NOAA’s 1991–2020 Climate Normals at Chicago Palwaukee Airport. 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 16 · Apr 30 · May 15 | Oct 1 · Oct 16 · Oct 27 | 167 days |
| 32°F freeze | Apr 4 · Apr 19 · May 3 | Oct 13 · Oct 26 · Nov 9 | 190 days |
| 28°F hard freeze | Mar 22 · Apr 5 · Apr 20 | Oct 26 · Nov 7 · Nov 21 | 212 days |
Average high temperature by month
1991–2020 normals at Chicago Palwaukee Airport
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 Mount Prospect, IL come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Chicago Palwaukee Airport (station USW00004838, elevation 636 ft), 4.2 mi from Mount Prospect. 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 Mount Prospect
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Prospect Heights, IL | 2.5 mi | Apr 19 | Oct 26 |
| Des Plaines, IL | 2.5 mi | Apr 16 | Oct 28 |
| Arlington Heights, IL | 3.1 mi | Apr 19 | Oct 26 |
| Rolling Meadows, IL | 4.3 mi | Apr 19 | Oct 26 |
| Wheeling, IL | 4.3 mi | Apr 19 | Oct 26 |
| Elk Grove Village, IL | 5.0 mi | Apr 16 | Oct 28 |
| Glenview, IL | 5.6 mi | Apr 26 | Oct 21 |
| Park Ridge, IL | 6.2 mi | Apr 16 | Oct 28 |
| Palatine, IL | 6.8 mi | Apr 25 | Oct 19 |
| Northbrook, IL | 6.8 mi | Apr 26 | Oct 21 |
Frequently asked questions
When is the last frost in Mount Prospect?
On average, the last spring frost (32°F) in Mount Prospect is around April 19. In about 1 year in 10 it comes after May 3, and in 9 years in 10 it comes after April 4.
When is the first frost in Mount Prospect?
The first fall frost (32°F) usually arrives around October 26. There’s a 10% chance of a freeze by October 13 and a 90% chance by November 9.
Can it frost in Mount Prospect 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 April 30.
What growing zone is Mount Prospect?
Mount Prospect 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 60056. See growing zones in Illinois.
More: all Illinois frost dates · Illinois growing zones · UV index today in Mount Prospect · frost vs. freeze