🌱 GrowGuide Almanac
HomeMichigan › Dearborn

Dearborn, MI Planting Calendar & Frost Dates

USDA hardiness zone 6b · ZIP 48120 · elevation 184′ · NOAA & USDA data

Dearborn is in USDA hardiness zone 6b (winters can dip to -5 to 0°F), with a growing season of about 181 days between the average last spring frost (April 27) and first fall frost (October 25). The warmest month is July (avg high 83.6°F); the coldest is January (avg low 17.7°F). It averages 35.1″ of precipitation a year and 30.8″ 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
6b
min temp -5 to 0°F
Last spring frost
April 27
avg (50% prob, 32°F)
First fall frost
October 25
avg (50% prob, 32°F)
Growing season
181 days
frost-free window
Warmest month
July
avg high 83.6°F

Month-by-month typical weather in Dearborn

Average conditions from the NOAA/NCEI 1991–2020 U.S. Climate Normals at Dearborn, MI (4 mi away). Temperatures °F, precipitation & snow in inches.

MonthAvg highAvg lowMeanPrecip (in)Snow (in)
January 32 17.7 24.8 2.5 11.7
February 34.9 19.1 27 2.3 7.3
March 45.2 26.4 35.8 2.3 5.7
April 58.3 36.9 47.6 3.3 0.6
May 70 47.5 58.8 3.6 0
June 79.2 57.8 68.5 3.3 0
July 83.6 62 72.8 3.5 0
August 81.8 60.8 71.3 3.2 0
September 75.1 53.4 64.3 3 0
October 62.1 41.6 51.9 2.9 0
November 48.3 32.3 40.3 2.7 0.9
December 36.9 24 30.5 2.5 4.6

What to plant when in Dearborn

CropSeasonWhat to do & when
TomatoeswarmStart seeds indoors: March 16 · Transplant out: May 4
PepperswarmStart seeds indoors: March 2 · Transplant out: May 11
CucumberswarmDirect sow: May 4
Zucchini / squashwarmDirect sow: May 4
Bush beanswarmDirect sow: May 4
Sweet cornwarmDirect sow: May 4
BasilwarmTransplant out: May 4
PeascoolSow (spring): March 23 · Sow (fall): August 30
SpinachcoolSow (spring): March 16 · Sow (fall): August 30
LettucecoolSow (spring): March 30 · Sow (fall): August 30
KalecoolTransplant (spring): April 6 · Sow (fall): August 16
BroccolicoolTransplant (spring): April 13
CarrotscoolSow (spring): April 6 · Sow (fall): August 16
OnionscoolTransplant (spring): March 30
PotatoescoolPlant seed potatoes: April 13
RadishescoolSow (spring): March 30 · Sow (fall): September 13

Dates are computed from Dearborn'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.

Want the exact dates for your yard? →
Look up your precise ZIP-code frost dates and a full 26-crop planting calendar on our free interactive tool.
Open the frost & planting tool

🌾 Get a frost reminder

One email in early spring and early fall with the dates for your area. No spam.

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 Michigan

Lincoln Park, MIDearborn Heights, MIDetroit, MITaylor, MIWestland, MILivonia, MIRoyal Oak, MISouthfield, MI

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 — Dearborn #2, MI, 3.1 mi (confidence: high). Monthly weather normals: Dearborn, MI, 4 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.