St. Charles, AR 72140 Frost Dates
St. Charles, AR: when does the frost end?
Typically, the last spring freeze lands around 03/17, roughly 201 days out. Fall's first freeze usually shows up around 11/10, roughly 238 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts St. Charles in Zone 8b (15 to 20°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
With roughly 11 weeks until St. Charles's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
03/17 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/28 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/05 and only about 1 year in 10 sees frost after that.
St. Charles against the rest of the dataset
At roughly 238 frost-free days, St. Charles places 9,050 of 40,283 ZIP codes in this dataset. Within AR, it ranks 121 of 687.
Learn more
Before leaning on 72140's figures: the frost range explains how to read the range around St. Charles's dates instead of trusting one, while local microclimates explains what one yard in St. Charles can differ from the 72140 normal.