Royal, IL 61871 Frost Dates
Royal, IL: when does the frost end?
The last spring frost here typically falls around 04/20, about 235 days from today. Fall's first freeze usually shows up around 10/21, roughly 182 days after the last spring frost.
Royal sits in USDA Zone 6a (-10 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 Royal's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Royal's last frost
04/20 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/07 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/07 and only about 1 year in 10 sees frost after that.
Royal against the rest of the dataset
Royal's growing season runs about 182 days, ranking 24,311 of 40,283 US ZIP codes measured here, longest to shortest. Within IL, it ranks 911 of 1,548.
Learn more
Before leaning on 61871's figures: local microclimates explains what one yard in Royal can differ from the 61871 normal, while zone vs. frost date explains why Zone 6a and Royal's frost date answer different questions.