Dayton, OH 45417 Frost Dates
45417, near Dayton, OH: the frost window
The last spring frost here typically falls around 04/16, about 231 days from today. Fall's first freeze usually shows up around 10/28, roughly 194 days after the last spring frost.
Zone 6b (-5 to 0°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Dayton, not a forecast for this year.
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.
The actual range around Dayton's last frost
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
About 194 days separate Dayton's last and first frost, putting it 19,411 of 40,283 ZIP codes nationally. Within OH, it ranks 150 of 1,383.
Learn more
Two guides worth reading on 45417: zone vs. frost date, on why Zone 6b and Dayton's frost date answer different questions, and the frost range, on how to read the range around Dayton's dates instead of trusting one.