St. Marys, OH 45885 Frost Dates
45885, near St. Marys, OH: the frost window
Around 04/27 is the usual last spring frost, about 242 days away. Fall's first freeze usually shows up around 10/19, roughly 175 days after the last spring frost.
Zone 6a (-10 to -5°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 St. Marys, not a forecast for this year.
Stretching the season past the first frost
St. Marys's growing season runs out in roughly 7 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 St. Marys's last frost
04/27 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/12 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/10 and only about 1 year in 10 sees frost after that.
St. Marys against the rest of the dataset
St. Marys's growing season runs about 175 days, ranking 26,847 of 40,283 US ZIP codes measured here, longest to shortest. Within OH, it ranks 1,019 of 1,383.
Learn more
Two guides worth reading on 45885: zone vs. frost date, on why Zone 6a and St. Marys's frost date answer different questions, and the frost range, on how to read the range around St. Marys's dates instead of trusting one.