St. Louis, MO 63188 Frost Dates
Frost dates for St. Louis, MO, ZIP 63188
Around 04/01 is the usual last spring frost, about 216 days away. The first fall frost typically arrives around 11/04, about 218 frost-free days later.
St. Louis sits in USDA Zone 7a (0 to 5°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.
What to do before the first frost
Zone 7a around St. Louis has about 10 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
Why 04/01 isn't a guarantee
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
St. Louis's growing season runs about 218 days, ranking 13,165 of 40,283 US ZIP codes measured here, longest to shortest. Within MO, it ranks 69 of 1,129.
Learn more
the frost range explains how to read the range around St. Louis's dates instead of trusting one, and local microclimates explains what one yard in St. Louis can differ from the 63188 normal.