Prairie du Rocher, IL 62277 Frost Dates
Prairie du Rocher, IL: when does the frost end?
Typically, the last spring freeze lands around 04/09, roughly 224 days out. Fall's first freeze usually shows up around 10/26, roughly 197 days after the last spring frost.
Prairie du Rocher sits in USDA Zone 7a (0 to 5°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
Stretching the season past the first frost
With roughly 8 weeks until Prairie du Rocher's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Prairie du Rocher's last frost
04/09 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/25 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/25 and only about 1 year in 10 sees frost after that.
Prairie du Rocher against the rest of the dataset
About 197 days separate Prairie du Rocher's last and first frost, putting it 18,786 of 40,283 ZIP codes nationally. Within IL, it ranks 321 of 1,548.
Learn more
Before leaning on 62277's figures: local microclimates explains what one yard in Prairie du Rocher can differ from the 62277 normal, while zone vs. frost date explains why Zone 7a and Prairie du Rocher's frost date answer different questions.