Frost Dates for 60927 — Clifton, Illinois

Half of springs at Watseka 2 NW, IL see their last 32°F night by April 24; only one in ten is past it by April 10, and one in ten still has one after May 10. Planting tender crops after April 30 leaves a 30% risk of a frost on them, after May 4 20%, and after May 10 10%. The 16 days between the even-odds date and the one-in-ten date is narrower than at 22% of the 158 Illinois stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 16 in half of years, as early as October 1 one year in ten, and holds off past October 28 one year in ten. A hard freeze of 28°F follows 10 days later, around October 26; in spring the one-in-ten date for 28°F is April 29, 11 days before the 32°F one. The freeze-free season lasts 174 days in a typical year, shorter than at 76% of the 158 Illinois stations; it reaches 194 days one year in ten and falls short of 153 one year in ten. On average 133 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 10 days longer, to about May 4, and return around October 5. Severe cold of 16°F or below comes every winter, usually between November 28 and March 11.

July is the warmest month at Watseka 2 NW, IL, averaging 85°F by day and 63°F at night; January is the coldest at 33°F and 16°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 29% of years.

Warmth for growing adds up to 3,256 growing degree days a year (base 50°F), fewer than at 66% of the 158 Illinois stations. 36% of them (1,164) have built up by the end of June, and July adds the most, 736. Precipitation totals 38.5 inches a year, most in June (5.0") and least in February (2.0"); May to September bring 53% of it.

The nearest other station, Kankakee Metro Wastewater, IL, 14 miles north of Clifton, has a last frost 5 days earlier (April 19), a first frost 8 days later (October 24), a season 14 days longer.

The first measurable snow (0.1 inch or more) in Clifton usually arrives around December 5, and the last of the season around March 15. Those are the middle dates across the winters of 1991–2020 at Watseka 2 NW, IL, 13.9 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 40 days after the last snow.

ZIP 60927 is 14 miles from Watseka 2 NW, IL, which stands at 620 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station; its figures are presented in full for 60970 (Watseka). The 2023 USDA Plant Hardiness Zone Map lists ZIP 60927 in zone 5b, the band where the coldest night of the year averaged -15 to -10°F (-26.1 to -23.3°C) over 1991–2020; a zone describes winter lows, not frost dates.