St. Louis, MO 63150 Frost Dates
St. Louis, MO: when does the frost end?
The last spring frost here typically falls around 04/01, about 216 days from today. Fall's first freeze usually shows up around 11/04, roughly 218 days after the last spring frost.
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.
Stretching the season past the first frost
With roughly 10 weeks until St. Louis's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around St. Louis's last frost
04/01 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/14 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/18 and only about 1 year in 10 sees frost after that.
St. Louis against the rest of the dataset
St. Louis's growing season runs about 218 days, ranking 13,150 of 40,283 US ZIP codes measured here, longest to shortest. Within MO, it ranks 54 of 1,129.
Learn more
Before leaning on 63150's figures: the frost range explains how to read the range around St. Louis's dates instead of trusting one, while local microclimates explains what one yard in St. Louis can differ from the 63150 normal.