Dayton, OH 45422 Frost Dates
45422, near Dayton, OH: the frost window
Typically, the last spring freeze lands around 04/16, roughly 231 days out. Fall's first freeze usually shows up around 10/28, roughly 194 days after the last spring frost.
Dayton sits in USDA Zone 6b (-5 to 0°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
Dayton's growing season runs out in roughly 9 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 04/16 isn't a guarantee
04/16 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/02 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/03 and only about 1 year in 10 sees frost after that.
Dayton against the rest of the dataset
At roughly 194 frost-free days, Dayton places 19,412 of 40,283 ZIP codes in this dataset. Within OH, it ranks 151 of 1,383.
Learn more
Two guides worth reading on 45422: local microclimates, on what one yard in Dayton can differ from the 45422 normal, and zone vs. frost date, on why Zone 6b and Dayton's frost date answer different questions.