Knox, IN 46534 Frost Dates
46534, near Knox, IN: the frost window
Around 04/26 is the usual last spring frost, about 241 days away. Fall's first freeze usually shows up around 10/19, roughly 174 days after the last spring frost.
Knox sits in USDA Zone 5b (-15 to -10°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
Knox'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.
How much risk comes with planting early here
04/26 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 05/12 and only about 1 year in 10 sees frost after that.
Knox against the rest of the dataset
Knox's growing season runs about 174 days, ranking 27,462 of 40,283 US ZIP codes measured here, longest to shortest. Within IN, it ranks 662 of 927.
Learn more
Two guides worth reading on 46534: local microclimates, on what one yard in Knox can differ from the 46534 normal, and zone vs. frost date, on why Zone 5b and Knox's frost date answer different questions.