Zone 5b Frost Dates and Planting Schedule

In USDA zone 5b, the typical last frost is April 30 and the typical first frost is October 11: the medians across its 2,758 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 11

range Sep 29 to Oct 22

Typical last spring frost

Apr 30

range Apr 19 to May 17

Median and 10th to 90th percentile across 2,758 ZIP codes in zone 5b, from each ZIP code's nearest NOAA station (1991–2020 normals). The spread is 28 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 5b 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 5b Planting Schedule

Typical for zone 5b, counted from the zone's typical Apr 30 last frost and Oct 11 first frost with the Season Planner's crop timing. Enter your ZIP code for your exact dates.

Typical for zone 5b

Mar 5–Mar 19 Start tomatoes indoors

Tomato seed needs 6 to 8 weeks under lights before it goes out.
Mar 19–Apr 2 Sow peas outdoors

Peas take cold soil and light frost in stride.
Apr 2–Apr 16 Sow leaf lettuce outdoors

Sow again every 2 to 3 weeks for a steady supply.
May 7–May 14 Transplant tomatoes and peppers

Once nights stay above 50°F.
May 7–May 14 Sow bush beans

Beans rot in cold soil: wait for 60°F at 4 inches deep.
Jul 19–Aug 2 Sow a fall crop

Kale, carrots, spinach or lettuce, 10 to 12 weeks before the first fall frost.
Oct 18–Oct 25 Plant garlic

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

Zone 5b Cities and Their Frost Dates

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

Fort Collins, CO:last frost May 3, first Oct 6
Des Moines, IA:last frost Apr 18, first Oct 20
Rockford, IL:last frost Apr 24, first Oct 17
Ames, IA:last frost Apr 26, first Oct 8
Augusta, ME:last frost Apr 27, first Oct 16
Aurora, IL:last frost Apr 25, first Oct 19
Cedar Rapids, IA:last frost Apr 27, first Oct 11
Cheyenne, WY:last frost May 12, first Oct 1

Zone 5b Frost FAQ

When is the last frost in zone 5b?

Typically around April 30, but it ranges from April 19 to May 17 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 5b?

Typically around October 11, ranging September 29 to October 22 across zone 5b.

When do you plant tomatoes in zone 5b?

Typically May 7 to May 14, 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 5b covers ZIP codes in Colorado, Iowa, Idaho, Illinois, Massachusetts, Maine, Michigan, Montana, Nebraska, New Hampshire, Nevada, New York, Pennsylvania, South Dakota, Utah, Vermont, Wisconsin, Wyoming.

A garden in a zone 5b climate — An illustration of a zone 5b garden.

Free book · 23 pages, PDF

The Spacing & Planting Cheat Sheet

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