St. Thomas, MO 65040 Frost Dates
65040, near St. Thomas, MO: the frost window
Typically, the last spring freeze lands around 04/07, roughly 222 days out. Fall's first freeze usually shows up around 11/01, roughly 208 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts St. Thomas in Zone 6b (-5 to 0°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
St. Thomas's growing season runs out in roughly 9 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
04/07 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/22 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/27 and only about 1 year in 10 sees frost after that.
St. Thomas against the rest of the dataset
St. Thomas's growing season runs about 208 days, ranking 15,757 of 40,283 US ZIP codes measured here, longest to shortest. Within MO, it ranks 188 of 1,129.
Learn more
Two guides worth reading on 65040: zone vs. frost date, on why Zone 6b and St. Thomas's frost date answer different questions, and the frost range, on how to read the range around St. Thomas's dates instead of trusting one.