FrostDateCheck

Merrillville, IN 46411 Frost Dates

When can you plant in Merrillville, IN?

Zone 6a

Typically, the last spring freeze lands around 04/29, roughly 244 days out. The first fall frost typically arrives around 10/16, about 171 frost-free days later.

Merrillville sits in USDA Zone 6a (-10 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.

What to do before the first frost

About 7 weeks of growing season left in Merrillville before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.

Why 04/29 isn't a guarantee

04/29 is the middle of 30 years of NOAA records, not a promise. Plant by 04/14 and you're betting against frost in roughly 9 years out of 10. 05/14 is the safer bet, historically only a 1-in-10 chance of frost that late.

How Merrillville compares

At roughly 171 frost-free days, Merrillville places 28,592 of 40,283 ZIP codes in this dataset. Within IN, it ranks 753 of 927.

Learn more

the frost range covers how to read the range around Merrillville's dates instead of trusting one. local microclimates covers what one yard in Merrillville can differ from the 46411 normal.