Zone 6b Frost Dates and Planting Schedule

In USDA zone 6b, the typical last frost is April 23 and the typical first frost is October 20: the medians across its 4,434 ZIP codes, from NOAA 1991–2020 normals at the station nearest each one.

By HarvestMath Editors October 1, 2026 Share:

Typical first fall frost

Oct 20

range Oct 5 to Oct 29

Typical last spring frost

Apr 23

range Apr 11 to May 11

Median and 10th to 90th percentile across 4,434 ZIP codes in zone 6b, from each ZIP code's nearest NOAA station (1991–2020 normals). The spread is 30 days in spring.

A hardiness zone is a winter-cold rating: the average coldest night of the year. It doesn't predict when frost ends in spring. Two ZIP codes in zone 6b can be weeks apart on their last frost, so the dates here are a typical range, not your date.

Your exact frost dates

Find your dates by

US ZIP code

Enter a ZIP code or pick your hardiness zone to see your frost dates.

Zone 6b Planting Schedule

Typical for zone 6b, counted from the zone's typical Apr 23 last frost and Oct 20 first frost with the Season Planner's crop timing. Enter your ZIP code for your exact dates.

Typical for zone 6b

Feb 26–Mar 12 Start tomatoes indoors

Tomato seed needs 6 to 8 weeks under lights before it goes out.
Mar 12–Mar 26 Sow peas outdoors

Peas take cold soil and light frost in stride.
Mar 26–Apr 9 Sow leaf lettuce outdoors

Sow again every 2 to 3 weeks for a steady supply.
Apr 30–May 7 Transplant tomatoes and peppers

Once nights stay above 50°F.
Apr 30–May 7 Sow bush beans

Beans rot in cold soil: wait for 60°F at 4 inches deep.
Jul 28–Aug 11 Sow a fall crop

Kale, carrots, spinach or lettuce, 10 to 12 weeks before the first fall frost.
Oct 27–Nov 3 Plant garlic

Cloves go in 1 to 2 weeks after the first killing frost, for next summer.

Zone 6b Cities and Their Frost Dates

Same zone, different dates: each city's own station.

Chicago, IL:last frost Apr 11, first Oct 31
Pittsburgh, PA:last frost Apr 18, first Oct 28
Columbus, OH:last frost Apr 18, first Oct 27
Cincinnati, OH:last frost Apr 16, first Oct 25
Indianapolis, IN:last frost Apr 15, first Oct 26
Detroit, MI:last frost Apr 21, first Oct 31
Dayton, OH:last frost Apr 16, first Oct 28
Springfield, MO:last frost Apr 9, first Oct 27

Zone 6b Frost FAQ

When is the last frost in zone 6b?

Typically around April 23, but it ranges from April 11 to May 11 across the zone's ZIP codes (10th to 90th percentile). Enter your ZIP code for your own station's date.

When is the first frost in zone 6b?

Typically around October 20, ranging October 5 to October 29 across zone 6b.

When do you plant tomatoes in zone 6b?

Typically Apr 30 to May 7, a week or two after the zone's typical last frost. Your own last frost can be weeks either side of that.

Neighboring Zones

Zone 6b covers ZIP codes in California, Colorado, Connecticut, Idaho, Illinois, Indiana, Kansas, Kentucky, Massachusetts, Michigan, Missouri, New Jersey, New Mexico, New York, Ohio, Oklahoma, Oregon, Pennsylvania, Utah, Washington, West Virginia.

A garden in a zone 6b climate — An illustration of a zone 6b garden.

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The Spacing & Planting Cheat Sheet

When to start, when to plant, how far apart.