Spencer, IN 47431 Frost Dates
Frost dates for Spencer, IN, ZIP 47431
Around 04/20 is the usual last spring frost, about 235 days away. The first fall frost typically arrives around 10/20, about 180 frost-free days later.
The USDA Plant Hardiness Zone Map puts Spencer in Zone 6a (-10 to -5°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
Zone 6a around Spencer 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.
Why 04/20 isn't a guarantee
04/20 is the middle of 30 years of NOAA records, not a promise. Plant by 04/06 and you're betting against frost in roughly 9 years out of 10. 05/07 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Spencer compares
Spencer's growing season runs about 180 days, ranking 24,881 of 40,283 US ZIP codes measured here, longest to shortest. Within IN, it ranks 490 of 927.
Learn more
the frost range explains how to read the range around Spencer's dates instead of trusting one, and local microclimates explains what one yard in Spencer can differ from the 47431 normal.