Frost Dates for Indianapolis, IN 46227

Last spring frost April 18 · First fall frost October 16 · 181 frost-free days · USDA Zone 6b

Frost probability for 46227

Frost10%50%90%
Spring (last frost)May 4April 18April 5
Fall (first frost)October 1October 16October 31

Dates come from NOAA 1971–2000 freeze probabilities at the nearest reporting station (7.1 km away); the 50% date is the median year.

Frost dates by ZIP code in Indianapolis, IN

ZIPLast spring frost (50%)First fall frost (50%)Zone
46227April 18October 166b
46226April 18October 166a
46237April 18October 166a
46254April 18October 166b
46224April 18October 166b
46222April 18October 166b
46219April 18October 166a
46203April 18October 166b
46220April 18October 166b
46217April 18October 166b
46235April 18October 166a
46260April 18October 166a
46239April 18October 166a
46241April 18October 166b
46201April 18October 166b
46218April 18October 166a
46229April 18October 166a
46234April 18October 166a
46205April 18October 166b
46221April 18October 166b
46236April 22October 176a
46268April 18October 166a
46214April 18October 166b
46208April 18October 166b
46256April 18October 166a
46202April 18October 166b
46240April 18October 166b
46250April 18October 166a
46228April 18October 166b
46259April 22October 156a
46204April 18October 166b
46231April 18October 166b
46278April 18October 166a
46280April 18October 166a
46225April 18October 166b
46216April 18October 166a
46290April 18October 166a
46206April 18October 166b

Month by month in Indianapolis

MonthWhat to do
JanuaryPlan your garden layout and order seeds. Research varieties suited to your frost dates.
FebruaryStart peppers and eggplant indoors 8–10 weeks before your last frost (around April 18). Start tomatoes about two weeks later, 6–8 weeks before last frost.
MarchStart herbs, basil, and squash indoors (4–6 weeks before frost). Direct sow peas, spinach, and lettuce if soil is workable.
AprilLast frost around April 18. Transplant cold-hardy crops (broccoli, kale, cabbage). Harden off tomato and pepper seedlings.
MayFrost has passed. Transplant tomatoes, peppers, and basil outdoors. Direct sow beans, cucumbers, squash, and zucchini.
JuneSuccession plant lettuce and greens. Keep beds weeded and watered consistently.
JulyHarvest regularly to encourage production. Monitor for pests and disease.
AugustMidsummer: harvest beans, zucchini, cucumbers. Start brassica seeds indoors for fall.
SeptemberFirst fall frost approaching (around October 16). Transplant fall brassicas. Sow spinach, arugula, and radishes.
OctoberFirst frost around October 16. Harvest tomatoes and peppers before frost. Cover cold-hardy crops with row covers to extend the season.
NovemberHarvest remaining cold-hardy crops: kale, carrots, and beets. Plant garlic bulbs for next year.
DecemberClean up spent plants. Add compost to beds. Rest, review, and plan next year's garden.

What grows in a 181-day season

Frequently Asked Questions

What is the last frost date for Indianapolis, IN (ZIP 46227)?

The median last spring frost date for Indianapolis, IN (ZIP code 46227) is around April 18. This is the 50th-percentile date — meaning half of all years see frost end before this date. Use the 10% and 90% dates to understand the full range of risk in your area.

What is the first fall frost date in Indianapolis, IN?

The median first fall frost date for Indianapolis, IN is around October 16. Plan to harvest or protect frost-sensitive crops like tomatoes and peppers at least a week before this date to avoid losses.

How long is the growing season in Indianapolis, IN?

The frost-free growing season in Indianapolis is about 181 days. This window — from your last spring frost to your first fall frost — is when warm-season vegetables thrive. Cold-hardy crops like kale, spinach, and peas can extend your season by weeks on either side.

What USDA hardiness zone is Indianapolis, IN?

Based on frost date patterns, Indianapolis falls approximately in 6b. USDA hardiness zones are determined by average annual minimum winter temperatures and guide both plant selection and planting timing for your location.

When should I start tomatoes indoors in Indianapolis, IN?

Start tomato seeds indoors 6–8 weeks before your last frost date (around April 18). For Indianapolis, that's roughly February 22 to March 7. Transplant outdoors 1–2 weeks after your last frost.

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