Frost Dates for 62088 — Staunton, Illinois

Half of springs at Hillsboro, IL see their last 32°F night by April 13; only one in ten is past it by March 30, and one in ten still has one after April 28. Planting tender crops after April 19 leaves a 30% risk of a frost on them, after April 23 20%, and after April 28 10%. The 15 days between the even-odds date and the one-in-ten date is narrower than at 54% of the 158 Illinois stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 24 in half of years, as early as October 10 one year in ten, and holds off past November 4 one year in ten. A hard freeze of 28°F follows 9 days later, around November 2; in spring the one-in-ten date for 28°F is April 18, 10 days before the 32°F one. The freeze-free season lasts 192 days in a typical year, longer than at 75% of the 158 Illinois stations; it reaches 212 days one year in ten and falls short of 170 one year in ten. On average 100 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 11 days longer, to about April 24, and return around October 13. Severe cold of 16°F or below comes every winter, usually between December 4 and March 3.

July is the warmest month at Hillsboro, IL, averaging 89°F by day and 67°F at night; January is the coldest at 38°F and 21°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 87% of years.

Warmth for growing adds up to 4,156 growing degree days a year (base 50°F), more than at 89% of the 158 Illinois stations. 38% of them (1,566) have built up by the end of June, and July adds the most, 857. Precipitation totals 42.0 inches a year, most in May (5.1") and least in January (2.5"); May to September bring 45% of it.

The nearest other station, Carlinville, IL, 20 miles north of Staunton, has a last frost 1 day later (April 14), a first frost 3 days earlier (October 21), a season 4 days shorter.

The first measurable snow (0.1 inch or more) in Staunton usually arrives around December 7, and the last of the season around March 5. Those are the middle dates across the winters of 1991–2020 at Mt Olive 1 E, IL, 6.3 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 39 days after the last snow.

ZIP 62088 is 19 miles from Hillsboro, IL, which stands at 630 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station; its figures are presented in full for 62056 (Litchfield). The 2023 USDA Plant Hardiness Zone Map lists ZIP 62088 in zone 6b, the band where the coldest night of the year averaged -5 to 0°F (-20.6 to -17.8°C) over 1991–2020; a zone describes winter lows, not frost dates.