Frost Dates for Cedar Rapids, IA

In Cedar Rapids, IA, the average last spring frost is around Apr 27 and the average first fall frost around Oct 11, for a growing season of about 165 days. For frost-tender plants, wait until May 11, when the chance of frost drops to 10%.

Average last frostApr 2750% chance of frost after this date
Safe to plantMay 11only a 10% chance of frost after
Average first frostOct 1150% chance of frost before this date
Growing season165 daysfrost-free in an average year

Based on NOAA 1991–2020 records from the Cedar Rapids Muni Airport, IA weather station, 6 miles away, elevation 868 ft. Frost can come earlier in low spots and valleys and later near cities and large lakes.

Frost probability by date

Chance of a 32°F frost after the spring date, or before the fall date.

ChanceLast spring frostFirst fall frost
10%May 11Sep 25
20%May 6Oct 1
30%May 3Oct 5
40%Apr 30Oct 8
50%Apr 27Oct 11
60%Apr 24Oct 13
70%Apr 22Oct 16
80%Apr 17Oct 19
90%Apr 13Oct 23

Light frost vs. hard freeze

Average (50%) dates for each temperature. Tender plants are damaged at 36°F; most hardy crops survive until 28°F.

TemperatureLast in springFirst in fall
Light frost (36°F)May 6Oct 1
Frost / freeze (32°F)Apr 27Oct 11
Hard freeze (28°F)Apr 16Oct 21

Planting calendar for Cedar Rapids

Start indoors Plant outside Fall planting
JanFebMarAprMayJunJulAugSepOctNovDec
Tomatoes
Indoors Mar 2 – Mar 16
Transplant May 4 – May 18
Peppers
Indoors Feb 16 – Mar 2
Transplant May 11 – May 25
Eggplant
Indoors Feb 16 – Mar 2
Transplant May 11 – May 25
Basil
Indoors Mar 16 – Mar 30
Transplant May 4 – May 18
Cucumbers
Indoors Mar 30 – Apr 6
Sow or transplant May 4 – May 18
Zucchini and summer squash
Indoors Mar 30 – Apr 6
Sow or transplant May 4 – May 18
Pumpkins and winter squash
Sow May 4 – May 18
Watermelons and melons
Indoors Mar 30 – Apr 6
Sow or transplant May 11 – May 25
Green beans
Sow May 4 – May 18
Sweet corn
Sow May 4 – May 18
Lettuce
Indoors Mar 16 – Mar 30
Sow or transplant Mar 30 – Apr 13
Fall sowing Aug 16 – Sep 13
Spinach
Sow Mar 16 – Apr 6
Fall sowing Aug 16 – Sep 6
Peas
Sow Mar 16 – Mar 30
Fall sowing Aug 2 – Aug 16
Kale
Indoors Mar 2 – Mar 16
Sow or transplant Mar 30 – Apr 13
Fall sowing Aug 2 – Aug 30
Broccoli
Indoors Mar 2 – Mar 16
Transplant Apr 13 – Apr 27
Fall sowing Jul 19 – Aug 2
Cabbage
Indoors Mar 2 – Mar 16
Transplant Apr 6 – Apr 20
Fall sowing Jul 19 – Aug 2
Carrots
Sow Apr 6 – Apr 27
Fall sowing Jul 19 – Aug 2
Radishes
Sow Mar 23 – Apr 13
Fall sowing Aug 30 – Sep 20
Beets
Sow Apr 6 – Apr 27
Fall sowing Aug 2 – Aug 16
Onions (sets or transplants)
Indoors Feb 2 – Feb 16
Plant Mar 30 – Apr 13
Potatoes
Plant Apr 6 – Apr 20
Garlic
Plant Oct 11 – Nov 8

Based on the average last frost (Apr 27) and first frost (Oct 11). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.

Nearby cities

MarionIowa CityWaterlooCedar FallsDubuqueDavenportMarshalltownBettendorfAll Iowa towns