Le Mars, IA 51031 Frost Dates
Le Mars, IA: when does the frost end?
Around 04/30 is the usual last spring frost, about 245 days away. Fall's first freeze usually shows up around 10/04, roughly 157 days after the last spring frost.
Zone 5a (-20 to -15°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 Le Mars, not a forecast for this year.
Stretching the season past the first frost
With roughly 5 weeks until Le Mars's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Le Mars's last frost
04/30 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/17 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/12 and only about 1 year in 10 sees frost after that.
Le Mars against the rest of the dataset
About 157 days separate Le Mars's last and first frost, putting it 33,280 of 40,283 ZIP codes nationally. Within IA, it ranks 828 of 1,042.
Learn more
Before leaning on 51031's figures: the frost range explains how to read the range around Le Mars's dates instead of trusting one, while local microclimates explains what one yard in Le Mars can differ from the 51031 normal.