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When to plant in North Liberty, IA

USDA Zone 5b

North Liberty, Iowa frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.

Zone 5b means North Liberty sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.

Station · IOWA CITY MUNI AP · 13.6 km
Last spring frost
April 21
50% chance · 32°F
First fall frost
October 18
50% chance · 32°F
Growing season
180 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for North LibertyA year-band showing 32°F frost risk from January to December for North Liberty: last spring frost around April 21, first fall frost around October 18, about 180 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

The average first fall frost in North Liberty is now 7 days later than in the 1981–2010 normals. See how frost dates are shifting nationwide →

Frost probability

IOWA CITY MUNI AP · 1991–2020

The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are North Liberty’s own odds, recorded at IOWA CITY MUNI AP.

Frost-probability curves for North LibertyProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around April 21 and the first fall frost around October 18, giving about 180 frost-free days.
Last spring frostFirst fall frostbold = 32°F · thin = 28°F / 36°F · dot = 50% date · band = 10–90% window
ThresholdSPRING 10%SPRING 50%SPRING 90%FALL 10%FALL 50%FALL 90%
36°FMay 15May 1Apr 17Sep 26Oct 9Oct 21
32°FMay 6Apr 21Apr 5Oct 4Oct 18Oct 31
28°FApr 27Apr 9Mar 25Oct 15Oct 28Nov 9

Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.

What to plant now

TODAY · JULY 19
Fall sowopen now
Rutabaga
July 12July 26
Fall sowin 7 days
Broccoli
July 26August 9
Fall sowin 7 days
Cabbage
July 26August 9
Fall sowin 7 days
Carrot
July 26August 9
Fall sowin 7 days
Cauliflower
July 26August 9
Fall sowin 7 days
Napa Cabbage
July 26August 23
Fall sowin 21 days
Beet
August 9August 23
Fall sowin 21 days
Collards
August 9September 6
Fall sowin 21 days
Endive
August 9August 23
Fall sowin 21 days
Escarole
August 9August 23
Fall sowin 21 days
Fennel (Bulb)
August 9August 23
Fall sowin 21 days
Kale
August 9September 6
Fall sowin 21 days
Kohlrabi
August 9September 6
Fall sowin 21 days
Peas
August 9August 23
Fall sowin 21 days
Radicchio
August 9August 23
Fall sowin 21 days
Swiss Chard
August 9August 23
Fall sowin 21 days
Turnip
August 9September 6

Add these crops to your calendar (.ics) ↓

Full-year planting calendar

Start indoorsTransplantDirect sowFall sow

Each bar is the exact window to take a planting action in North Liberty, drawn to the day from the local frost dates. The dashed line is today.

Nearby weather stations

3 within 18 km · complete 32°F normals

When stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.

IOWA CITY MUNI AP
Primary
14 km · 198 m elevation
SPRING
Apr 21
FALL
Oct 18
IOWA CITY
17 km · 195 m elevation
SPRING
Apr 29
FALL
Oct 9
CEDAR RAPIDS MUNI AP
18 km · 265 m elevation
SPRING
Apr 27
FALL
Oct 11

North Liberty planting FAQ

When is the last spring frost in North Liberty, IA?

On average, the last spring frost in North Liberty is around April 21 (50% probability at 32°F, from 1991–2020 NOAA normals). Wait until after this date to set out tender plants like tomatoes and peppers.

When is the first fall frost in North Liberty, IA?

In North Liberty, the first 32°F freeze of fall lands around October 18 on average. Time your last harvests and any season-extension cover before it.

What hardiness zone is North Liberty in?

North Liberty is in USDA hardiness zone 5b. In zone 5b, winters are cold — pick cold-hardy varieties and protect tender crops.

How long is the growing season in North Liberty?

There are roughly 180 frost-free days in North Liberty (a moderate growing season), running from the average last frost around April 21 to the first fall frost near October 18.

When should I plant tomatoes in North Liberty?

In North Liberty, start tomato seeds indoors around February 24–March 10, then transplant seedlings outdoors around April 28 once the danger of frost has passed.

Planting reminders

Never miss a window in North Liberty

An email when it’s time to start seeds, transplant, and sow — timed to North Liberty’s frost dates. Double opt-in, one-click unsubscribe, no spam.

Nearby cities

8 within reach

Frost dates recorded at IOWA CITY MUNI AP, 14 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.

Cite this page
BlissGarden. "When to Plant in North Liberty, IA — Frost Dates & Zone 5b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00014937. Retrieved from https://blissgarden.com/iowa/north-liberty.
When to Plant in North Liberty, IA — Frost Dates & Zone 5b — BlissGarden