Des Moines, IA 50320 Frost Dates
When can you plant in Des Moines, IA?
Around 04/18 is the usual last spring frost, about 233 days away. The first fall frost typically arrives around 10/20, about 184 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 Des Moines, not a forecast for this year.
What to do before the first frost
About 8 weeks of growing season left in Des Moines before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 04/18 isn't a guarantee
04/18 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. 05/02 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Des Moines compares
Des Moines's growing season runs about 184 days, ranking 23,383 of 40,283 US ZIP codes measured here, longest to shortest. Within IA, it ranks 51 of 1,042.
Learn more
local microclimates covers what one yard in Des Moines can differ from the 50320 normal. zone vs. frost date covers why Zone 5b and Des Moines's frost date answer different questions.