When is the last frost in Cedar Rapids, IA?

The average last spring frost (50% probability of 32°F) in Cedar Rapids is around April 28, based on NOAA/NCEI 1991–2020 normals at the Cedar Rapids #1, IA station (6.3 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 Cedar Rapids?

The average first fall frost in Cedar Rapids, IA is around October 12, giving roughly a 166-day frost-free growing season.

What planting zone is Cedar Rapids, IA?

Cedar Rapids is in USDA plant hardiness zone 5b (average annual extreme minimum temperature -15 to -10°F), from the 2023 USDA Plant Hardiness Zone Map.

What is the weather like in Cedar Rapids?

In Cedar Rapids, IA the warmest month is July (avg high 85.5°F) and the coldest is January (avg low 12.5°F). It averages about 38.8″ of precipitation a year and 34.3″ of snow.

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Cedar Rapids, IA Planting Calendar & Frost Dates

USDA hardiness zone 5b · ZIP 52401 · elevation 248′ · NOAA & USDA data

Cedar Rapids is in USDA hardiness zone 5b (winters can dip to -15 to -10°F), with a growing season of about 166 days between the average last spring frost (April 28) and first fall frost (October 12). The warmest month is July (avg high 85.5°F); the coldest is January (avg low 12.5°F). It averages 38.8″ of precipitation a year and 34.3″ 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 -15 to -10°F

Last spring frost

April 28

avg (50% prob, 32°F)

First fall frost

October 12

avg (50% prob, 32°F)

Growing season

166 days

frost-free window

Warmest month

July

avg high 85.5°F

Month-by-month typical weather in Cedar Rapids

Average conditions from the NOAA/NCEI 1991–2020 U.S. Climate Normals at Cedar Rapids #1, IA (6.3 mi away). Temperatures °F, precipitation & snow in inches.

Month	Avg high	Avg low	Mean	Precip (in)	Snow (in)
January	30	12.5	21.3	1.2	8.7
February	35.1	16.6	25.9	1.3	8.3
March	48.9	27.5	38.2	2.1	4
April	63.3	38.4	50.9	4	1.5
May	73.8	49.6	61.7	4.7	0
June	82.3	59.6	71	5.7	0
July	85.5	63.3	74.4	4.5	0
August	83.4	61.2	72.3	4.4	0
September	77.3	53	65.2	4	0
October	64.1	41.5	52.8	3	0.6
November	48.1	29.3	38.7	2.2	2.2
December	34.7	18.6	26.7	1.7	9

What to plant when in Cedar Rapids

Crop	Season	What to do & when
Tomatoes	warm	Start seeds indoors: March 17 · Transplant out: May 5
Peppers	warm	Start seeds indoors: March 3 · Transplant out: May 12
Cucumbers	warm	Direct sow: May 5
Zucchini / squash	warm	Direct sow: May 5
Bush beans	warm	Direct sow: May 5
Sweet corn	warm	Direct sow: May 5
Basil	warm	Transplant out: May 5
Peas	cool	Sow (spring): March 24 · Sow (fall): August 17
Spinach	cool	Sow (spring): March 17 · Sow (fall): August 17
Lettuce	cool	Sow (spring): March 31 · Sow (fall): August 17
Kale	cool	Transplant (spring): April 7 · Sow (fall): August 3
Broccoli	cool	Transplant (spring): April 14
Carrots	cool	Sow (spring): April 7 · Sow (fall): August 3
Onions	cool	Transplant (spring): March 31
Potatoes	cool	Plant seed potatoes: April 14
Radishes	cool	Sow (spring): March 31 · Sow (fall): August 31

Dates are computed from Cedar Rapids'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.

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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 Iowa

Iowa City, IA Waterloo, IA Cedar Falls, IA Dubuque, IA Davenport, IA Ames, IA Ankeny, IA Des Moines, IA

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 — Cedar Rapids #1, IA, 6.3 mi (confidence: high). Monthly weather normals: Cedar Rapids #1, IA, 6.3 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.