Unionville, MO 63565 Frost Dates
Frost dates for Unionville, MO, ZIP 63565
Around 04/17 is the usual last spring frost, about 232 days away. The first fall frost typically arrives around 10/22, about 186 frost-free days later.
Zone 5b (-15 to -10°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 Unionville, not a forecast for this year.
What to do before the first frost
Zone 5b around Unionville has about 8 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.
How much risk comes with planting early here
04/17 is the middle of 30 years of NOAA records, not a promise. Plant by 04/04 and you're betting against frost in roughly 9 years out of 10. 04/30 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Unionville compares
About 186 days separate Unionville's last and first frost, putting it 22,868 of 40,283 ZIP codes nationally. Within MO, it ranks 879 of 1,129.
Learn more
zone vs. frost date explains why Zone 5b and Unionville's frost date answer different questions, and the frost range explains how to read the range around Unionville's dates instead of trusting one.