When is the last frost in Indianapolis, IN?

The average last spring frost (50% probability of 32°F) in Indianapolis is around April 20, based on NOAA/NCEI 1991–2020 normals at the Indianapolis Se Side, IN station (4.5 mi away). Half of years it falls outside that date, so wait 1–2 weeks past it before setting out frost-tender plants.

When is the first fall frost in Indianapolis?

The average first fall frost in Indianapolis, IN is around October 21, giving roughly a 183-day frost-free growing season.

What planting zone is Indianapolis, IN?

Indianapolis is in USDA plant hardiness zone 6b (average annual extreme minimum temperature -5 to 0°F), from the 2023 USDA Plant Hardiness Zone Map.

What is the weather like in Indianapolis?

In Indianapolis, IN the warmest month is July (avg high 84.8°F) and the coldest is January (avg low 19.8°F). It averages about 47.2″ of precipitation a year and 26.7″ of snow.

Home › Indiana › Indianapolis

Indianapolis, IN Planting Calendar & Frost Dates

USDA hardiness zone 6b · ZIP 46201 · elevation 251′ · NOAA & USDA data

Indianapolis is in USDA hardiness zone 6b (winters can dip to -5 to 0°F), with a growing season of about 183 days between the average last spring frost (April 20) and first fall frost (October 21). The warmest month is July (avg high 84.8°F); the coldest is January (avg low 19.8°F). It averages 47.2″ of precipitation a year and 26.7″ of snow, mostly mid-winter. Start cool-season crops several weeks before the last frost; wait until after it for tomatoes, peppers and other tender crops.

Hardiness zone

min temp -5 to 0°F

Last spring frost

April 20

avg (50% prob, 32°F)

First fall frost

October 21

avg (50% prob, 32°F)

Growing season

183 days

frost-free window

Warmest month

July

avg high 84.8°F

Month-by-month typical weather in Indianapolis

Average conditions from the NOAA/NCEI 1991–2020 U.S. Climate Normals at Castleton 2 S, IN (8 mi away). Temperatures °F, precipitation & snow in inches.

Month	Avg high	Avg low	Mean	Precip (in)	Snow (in)
January	35.7	19.8	27.8	3.3	8.4
February	40.6	22.7	31.6	2.7	7.2
March	51.3	32.1	41.7	3.9	3.6
April	64.3	42	53.1	4.6	0.2
May	73.8	52.1	62.9	4.9	0
June	81.9	61.7	71.8	5.6	0
July	84.8	65.1	74.9	4.7	0
August	82.9	63.3	73.1	3.9	0
September	76.7	55.9	66.3	3.6	0
October	64.6	44.5	54.5	3.4	0
November	51.5	33.7	42.6	3.5	0.6
December	39.9	25.2	32.6	3.2	6.7

What to plant when in Indianapolis

Crop	Season	What to do & when
Tomatoes	warm	Start seeds indoors: March 9 · Transplant out: April 27
Peppers	warm	Start seeds indoors: February 23 · Transplant out: May 4
Cucumbers	warm	Direct sow: April 27
Zucchini / squash	warm	Direct sow: April 27
Bush beans	warm	Direct sow: April 27
Sweet corn	warm	Direct sow: April 27
Basil	warm	Transplant out: April 27
Peas	cool	Sow (spring): March 16 · Sow (fall): August 26
Spinach	cool	Sow (spring): March 9 · Sow (fall): August 26
Lettuce	cool	Sow (spring): March 23 · Sow (fall): August 26
Kale	cool	Transplant (spring): March 30 · Sow (fall): August 12
Broccoli	cool	Transplant (spring): April 6
Carrots	cool	Sow (spring): March 30 · Sow (fall): August 12
Onions	cool	Transplant (spring): March 23
Potatoes	cool	Plant seed potatoes: April 6
Radishes	cool	Sow (spring): March 23 · Sow (fall): September 9

Dates are computed from Indianapolis's average frost dates using standard cool-/warm-season timing. They're a starting point — a cold spring, a warm microclimate, or a fast-maturing variety can shift them by a week or two.

Want the exact dates for your yard? →
Look up your precise ZIP-code frost dates and a full 26-crop planting calendar on our free interactive tool.
Open the frost & planting tool

🌾 Get a frost reminder

One email in early spring and early fall with the dates for your area. No spam.

Gear that helps you plant on time

Some links below are Amazon affiliate links (tag theboringthin-20). If you buy through them we may earn a small commission at no extra cost to you — it keeps this almanac free. We only list generic, genuinely-useful categories.

Soil thermometer →Know when the ground is warm enough to sow — the honest signal, not the calendar.Seed-starting trays + dome →Start tomatoes & peppers indoors on the schedule below.Seedling heat mat →Warms the soil for faster, more even germination indoors.Floating row cover / frost cloth →Buys you 4–8°F to beat an early or late frost.Raised garden bed kit →Warms and drains faster in spring than in-ground soil.Garden gloves →Basic kit for transplant day.

Nearby cities in Indiana

Greenwood, IN Carmel, IN Fishers, IN Noblesville, IN Anderson, IN Columbus, IN Muncie, IN Bloomington, IN

Sources & method. Hardiness zone: 2023 USDA Plant Hardiness Zone Map (PRISM Climate Group, Oregon State University). Frost dates & growing season: NOAA/NCEI 1991–2020 U.S. Climate Normals, nearest station with published freeze normals — Indianapolis Se Side, IN, 4.5 mi (confidence: high). Monthly weather normals: Castleton 2 S, IN, 8 mi (confidence: high). ZIP centroid from U.S. Census 2023 ZCTA data. Frost dates are the 50%-probability date — half of years frost occurs outside the stated date. Nothing here is invented; where the nearest station is far, we say so. Last updated 2026-07-22.