When is the last frost in Dayton, OH?

The average last spring frost (50% probability of 32°F) in Dayton is around April 18, based on NOAA/NCEI 1991–2020 normals at the Dayton Mcd, OH station (0.9 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 Dayton?

The average first fall frost in Dayton, OH is around October 25, giving roughly a 189-day frost-free growing season.

What planting zone is Dayton, OH?

Dayton is in USDA plant hardiness zone 6b (average annual extreme minimum temperature -5 to 0°F), from the 2023 USDA Plant Hardiness Zone Map.

What is the weather like in Dayton?

In Dayton, OH the warmest month is July (avg high 86.7°F) and the coldest is January (avg low 20.1°F). It averages about 41.7″ of precipitation a year and 12.3″ of snow.

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Dayton, OH Planting Calendar & Frost Dates

USDA hardiness zone 6b · ZIP 45402 · elevation 220′ · NOAA & USDA data

Dayton is in USDA hardiness zone 6b (winters can dip to -5 to 0°F), with a growing season of about 189 days between the average last spring frost (April 18) and first fall frost (October 25). The warmest month is July (avg high 86.7°F); the coldest is January (avg low 20.1°F). It averages 41.7″ of precipitation a year and 12.3″ 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 -5 to 0°F

Last spring frost

April 18

avg (50% prob, 32°F)

First fall frost

October 25

avg (50% prob, 32°F)

Growing season

189 days

frost-free window

Warmest month

July

avg high 86.7°F

Month-by-month typical weather in Dayton

Average conditions from the NOAA/NCEI 1991–2020 U.S. Climate Normals at Dayton Mcd, OH (0.9 mi away). Temperatures °F, precipitation & snow in inches.

Month	Avg high	Avg low	Mean	Precip (in)	Snow (in)
January	36.3	20.1	28.2	3.2	6.9
February	40.2	22.6	31.4	2.4	1.5
March	50.7	30.6	40.6	3.5	1.7
April	64.3	41.4	52.9	4.5	0
May	74.9	52.9	63.9	4.4	0
June	83.6	62.4	73	4.4	0
July	86.7	65.7	76.2	4	0
August	85.8	63.9	74.8	3.1	0
September	79.2	55.8	67.5	3	0
October	66.1	43.5	54.8	3	0
November	52	33.1	42.6	3	0.1
December	40.9	25.6	33.2	3.1	2.1

What to plant when in Dayton

Crop	Season	What to do & when
Tomatoes	warm	Start seeds indoors: March 7 · Transplant out: April 25
Peppers	warm	Start seeds indoors: February 21 · Transplant out: May 2
Cucumbers	warm	Direct sow: April 25
Zucchini / squash	warm	Direct sow: April 25
Bush beans	warm	Direct sow: April 25
Sweet corn	warm	Direct sow: April 25
Basil	warm	Transplant out: April 25
Peas	cool	Sow (spring): March 14 · Sow (fall): August 30
Spinach	cool	Sow (spring): March 7 · Sow (fall): August 30
Lettuce	cool	Sow (spring): March 21 · Sow (fall): August 30
Kale	cool	Transplant (spring): March 28 · Sow (fall): August 16
Broccoli	cool	Transplant (spring): April 4
Carrots	cool	Sow (spring): March 28 · Sow (fall): August 16
Onions	cool	Transplant (spring): March 21
Potatoes	cool	Plant seed potatoes: April 4
Radishes	cool	Sow (spring): March 21 · Sow (fall): September 13

Dates are computed from Dayton'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 Ohio

Middletown, OH Springfield, OH Hamilton, OH Fairfield, OH Cincinnati, OH Grove City, OH Dublin, OH Columbus, OH

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 — Dayton Mcd, OH, 0.9 mi (confidence: high). Monthly weather normals: Dayton Mcd, OH, 0.9 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.