St. Louis, MO 63160 Frost Dates
When can you plant in St. Louis, MO?
Typically, the last spring freeze lands around 04/01, roughly 216 days out. The first fall frost typically arrives around 11/04, about 218 frost-free days later.
Zone 7a (0 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. Louis, not a forecast for this year.
What to do before the first frost
About 10 weeks of growing season left in St. Louis before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
How much risk comes with planting early here
04/01 is the middle of 30 years of NOAA records, not a promise. Plant by 03/14 and you're betting against frost in roughly 9 years out of 10. 04/18 is the safer bet, historically only a 1-in-10 chance of frost that late.
How St. Louis compares
About 218 days separate St. Louis's last and first frost, putting it 13,155 of 40,283 ZIP codes nationally. Within MO, it ranks 59 of 1,129.
Learn more
zone vs. frost date covers why Zone 7a and St. Louis's frost date answer different questions. the frost range covers how to read the range around St. Louis's dates instead of trusting one.