FrostDateCheck

St. Louis, MO 63177 Frost Dates

When can you plant in St. Louis, MO?

Zone 7a

The last spring frost here typically falls around 04/01, about 216 days from today. 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

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.

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

About 218 days separate St. Louis's last and first frost, putting it 13,161 of 40,283 ZIP codes nationally. Within MO, it ranks 65 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.