Topeka, KS 66409 Frost Dates
66409, near Topeka, KS: the frost window
Typically, the last spring freeze lands around 04/15, roughly 230 days out. Fall's first freeze usually shows up around 10/21, roughly 185 days after the last spring frost.
Topeka 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
Topeka'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.
How much risk comes with planting early here
04/15 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 04/30 and only about 1 year in 10 sees frost after that.
Topeka against the rest of the dataset
About 185 days separate Topeka's last and first frost, putting it 23,009 of 40,283 ZIP codes nationally. Within KS, it ranks 403 of 745.
Learn more
Two guides worth reading on 66409: zone vs. frost date, on why Zone 6b and Topeka's frost date answer different questions, and the frost range, on how to read the range around Topeka's dates instead of trusting one.