When is the last frost in Quincy, IL?

The average last spring frost (50% probability of 32°F) in Quincy is around April 8, based on NOAA/NCEI 1991–2020 normals at the Quincy Dam 21, IL station (2.8 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 Quincy?

The average first fall frost in Quincy, IL is around October 30, giving roughly a 204-day frost-free growing season.

What planting zone is Quincy, IL?

Quincy is in USDA plant hardiness zone 6a (average annual extreme minimum temperature -10 to -5°F), from the 2023 USDA Plant Hardiness Zone Map.

What is the weather like in Quincy?

In Quincy, IL the warmest month is July (avg high 87.2°F) and the coldest is January (avg low 18.9°F). It averages about 36.5″ of precipitation a year.

Home › Illinois › Quincy

Quincy, IL Planting Calendar & Frost Dates

USDA hardiness zone 6a · ZIP 62301 · elevation 147′ · NOAA & USDA data

Quincy is in USDA hardiness zone 6a (winters can dip to -10 to -5°F), with a growing season of about 204 days between the average last spring frost (April 8) and first fall frost (October 30). The warmest month is July (avg high 87.2°F); the coldest is January (avg low 18.9°F). It averages 36.5″ of precipitation a year. 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 -10 to -5°F

Last spring frost

April 8

avg (50% prob, 32°F)

First fall frost

October 30

avg (50% prob, 32°F)

Growing season

204 days

frost-free window

Warmest month

July

avg high 87.2°F

Month-by-month typical weather in Quincy

Average conditions from the NOAA/NCEI 1991–2020 U.S. Climate Normals at Quincy Dam 21, IL (2.8 mi away). Temperatures °F, precipitation & snow in inches.

Month	Avg high	Avg low	Mean	Precip (in)	Snow (in)
January	35.1	18.9	27	1.7	–
February	40.4	22.7	31.6	1.9	–
March	51.8	32	41.9	2.5	–
April	64.4	42.9	53.6	4.2	–
May	74.1	54.2	64.1	4.8	–
June	83.4	63.9	73.6	4.1	–
July	87.2	67.6	77.4	3.6	–
August	85.6	65.7	75.7	3.3	–
September	78.9	57.1	68	3.4	–
October	66.6	45.4	56	2.7	–
November	52.5	33.8	43.2	2.6	–
December	40.2	24.5	32.3	1.7	–

What to plant when in Quincy

Crop	Season	What to do & when
Tomatoes	warm	Start seeds indoors: February 25 · Transplant out: April 15
Peppers	warm	Start seeds indoors: February 11 · Transplant out: April 22
Cucumbers	warm	Direct sow: April 15
Zucchini / squash	warm	Direct sow: April 15
Bush beans	warm	Direct sow: April 15
Sweet corn	warm	Direct sow: April 15
Basil	warm	Transplant out: April 15
Peas	cool	Sow (spring): March 4 · Sow (fall): September 4
Spinach	cool	Sow (spring): February 25 · Sow (fall): September 4
Lettuce	cool	Sow (spring): March 11 · Sow (fall): September 4
Kale	cool	Transplant (spring): March 18 · Sow (fall): August 21
Broccoli	cool	Transplant (spring): March 25
Carrots	cool	Sow (spring): March 18 · Sow (fall): August 21
Onions	cool	Transplant (spring): March 11
Potatoes	cool	Plant seed potatoes: March 25
Radishes	cool	Sow (spring): March 11 · Sow (fall): September 18

Dates are computed from Quincy'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 Illinois

Springfield, IL Peoria, IL Rock Island, IL Moline, IL Belleville, IL Decatur, IL Bloomington, IL Normal, IL

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 — Quincy Dam 21, IL, 2.8 mi (confidence: high). Monthly weather normals: Quincy Dam 21, IL, 2.8 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.