Frost Dates for 62557 — Pana, Illinois

Half of springs at Pana, IL see their last 32°F night by April 17; only one in ten is past it by April 4, and one in ten still has one after May 3. Planting tender crops after April 24 leaves a 30% risk of a frost on them, after April 28 20%, and after May 3 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 23 in half of years, as early as October 8 one year in ten, and holds off past November 3 one year in ten. A hard freeze of 28°F follows 9 days later, around November 1; in spring the one-in-ten date for 28°F is April 21, 12 days before the 32°F one. The freeze-free season lasts 188 days in a typical year, longer than at 58% of the 158 Illinois stations; it reaches 208 days one year in ten and falls short of 165 one year in ten. On average 114 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 28, and return around October 12. Severe cold of 16°F or below comes every winter, usually between December 4 and March 5.

July is the warmest month at Pana, IL, averaging 87°F by day and 65°F at night; January is the coldest at 37°F and 19°F. A freezing night is all but certain in every month from November 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 14% of years.

Warmth for growing adds up to 3,750 growing degree days a year (base 50°F), more than at 70% of the 158 Illinois stations. 36% of them (1,358) have built up by the end of June, and July adds the most, 812. Precipitation totals 42.5 inches a year, most in June (5.1") and least in February (2.2"); May to September bring 48% of it.

The nearest other station, Shelbyville Dam, IL, 16 miles east of Pana, has a last frost 7 days earlier (April 10), a first frost 1 day later (October 24), a season 7 days longer.

The first measurable snow (0.1 inch or more) in Pana usually arrives around December 10, and the last of the season around March 8. Those are the middle dates across the winters of 1991–2020 at Pana, IL, 1.7 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 62557 is 2 miles from Pana, IL, which stands at 650 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 62557 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.