Union City, IN 47390 Frost Dates
47390, near Union City, IN: the frost window
Around 04/21 is the usual last spring frost, about 236 days away. Fall's first freeze usually shows up around 10/20, roughly 180 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Union City in Zone 6a (-10 to -5°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
Union City's growing season runs out in roughly 8 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 04/21 isn't a guarantee
04/21 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.
Union City against the rest of the dataset
At roughly 180 frost-free days, Union City places 24,866 of 40,283 ZIP codes in this dataset. Within IN, it ranks 489 of 927.
Learn more
Two guides worth reading on 47390: the frost range, on how to read the range around Union City's dates instead of trusting one, and local microclimates, on what one yard in Union City can differ from the 47390 normal.