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Last and first frost dates in Dayton

United States

In Dayton the last spring frost usually comes around 17 April and the first autumn frost around 9 November, which leaves about 206 frost-free days (median of 2016–2025). Tomato seedlings can go into open ground from 4 May to 20 July.

Last spring frostaround 17 April
First autumn frostaround 9 November
Frost-free days206 days

Median of 2016–2025 for the 25 km grid cell of the city: the last day at or below 0 °C in spring and the first in autumn (ERA5 reanalysis via Open-Meteo). In a cold year a frost can come a week or two later — Greenly warns 48 hours ahead.

When is the last frost in Dayton?

The last frost in Dayton usually comes around 17 April: that is the median of 2016–2025, so in about half of those years the last night at or below 0 °C came later. Hardy crops start before it and frost-tender ones only after it: in the table below arugula can go into open ground from 27 March, while corn waits until 24 April. The first autumn frost follows around 9 November, about 206 days later: harvest or cover frost-tender crops before then.

When to sow and plant

CropSow for seedlingsPlant out in a greenhouseOpen ground
Achocha22 February – 1 August3 April – 10 September24 April – 10 September
Ageratumfrom 16 February—from 4 May
Arugula——sow 27 March – 5 October
Basil18 March – 7 September25 April – 15 October16 May – 15 October
Beet——sow 27 March – 10 September
Bell Pepper24 February – 21 May25 April – 20 July16 May – 20 July
Black-eyed Susanfrom 31 January—from 24 April
Bok Choy27 February – 18 September3 April – 23 October24 April – 23 October
Borage——sow 24 April – 15 September
Broad bean——sow 27 March – 1 August
Broccoli——sow 27 March – 25 July
Brussels Sprouts20 January – 22 June6 March – 6 August27 March – 6 August
Busy Lizziefrom 30 January—from 24 April
Cabbage——sow 27 March – 2 July
Calendula——sow from 27 March
Carrot——sow 27 March – 17 August
Cauliflower23 January – 25 July6 March – 5 September27 March – 5 September
Celeriac16 January – 22 May3 April – 7 August24 April – 7 August
Celery16 January – 1 June3 April – 17 August24 April – 17 August
Celosiafrom 5 Marchfrom 19 Aprilfrom 10 May
Chamomile——sow 27 March – 5 September
Chayote5 January – 15 May3 April – 11 August24 April – 11 August
Chickpea——sow 27 March – 22 July
Chicory9 February – 16 August—27 March – 10 September
Chili Pepper24 February – 27 June25 April – 26 August16 May – 26 August
China asterfrom 4 Marchfrom 25 Aprilfrom 16 May
Chives——sow 27 March – 27 August
Cilantro——sow 27 March – 6 September
Corn——sow 24 April – 22 July
Corn poppy——sow from 27 March
Cosmosfrom 5 Marchfrom 19 Aprilfrom 10 May
Cucumber28 March – 28 July25 April – 25 August16 May – 25 August
Daikon——sow 27 March – 3 September
Delphiniumfrom 6 January—from 27 March
Dill——sow 27 March – 16 September
Edging lobeliafrom 30 January—from 24 April
Eggplant24 February – 21 May25 April – 20 July16 May – 20 July
Florence fennel17 February – 1 August3 April – 15 September24 April – 15 September
Foxglovefrom 19 December—from 27 March
Garden sorrel——sow 27 March – 4 September
Green Beans——sow 10 May – 30 July
Hollyhock——sow from 27 March
Hyssop——sow 27 March – 28 July
Kale——sow 27 March – 29 August
Kiwano12 March – 4 August13 April – 5 September4 May – 5 September
Kohlrabi——sow 27 March – 8 September
Leek26 December – 13 May6 March – 22 July27 March – 22 July
Lemon balm——sow 27 March – 31 August
Lettuce——sow 27 March – 13 September
Lisianthusfrom 9 Decemberfrom 6 Marchfrom 27 March
Lovage——sow from 27 March
Luffa14 March – 29 May25 April – 10 July16 May – 10 July
Marigoldfrom 20 Februaryfrom 3 Aprilfrom 24 April
Marjoram24 February – 16 August—16 May – 15 October
Melon28 March – 15 July25 April – 12 August16 May – 12 August
Microgreens——sow 10 May – 26 October
Moringa11 March – 21 August5 May – 15 October26 May – 15 October
Moss rosefrom 6 February—from 24 April
Mustard greens——sow 27 March – 25 September
Napa cabbage1 March – 26 August3 April – 28 September24 April – 28 September
Nasturtiumfrom 24 Februaryfrom 3 Aprilfrom 24 April
Okra14 March – 9 August25 April – 20 September16 May – 20 September
Oregano5 January – 6 August6 March – 5 October27 March – 5 October
Pansyfrom 9 Januaryfrom 6 Marchfrom 27 March
Parsley——sow 27 March – 25 August
Parsnip——sow 27 March – 14 July
Peanut19 March – 5 July25 April – 11 August16 May – 11 August
Peas——sow 27 March – 27 August
Petuniafrom 21 Februaryfrom 25 Aprilfrom 16 May
Physalis27 February – 2 July13 April – 16 August4 May – 16 August
Pumpkin14 March – 3 June25 April – 15 July16 May – 15 July
Purple coneflowerfrom 3 January—from 27 March
Radish——sow 27 March – 10 October
Sage16 January – 2 August6 March – 20 September27 March – 20 September
Scarlet sagefrom 20 February—from 4 May
Snapdragonfrom 31 Decemberfrom 6 Marchfrom 27 March
Soybean——sow 16 May – 21 August
Spinach——sow 27 March – 15 September
Stevia23 February – 23 June13 April – 11 August4 May – 11 August
Stock——sow from 27 March
Sunflower——sow from 10 May
Sweet alyssum——sow from 27 March
Sweet Corn12 March – 16 August3 April – 7 September24 April – 7 September
Sweet peafrom 23 Januaryfrom 6 Marchfrom 27 March
Sweet William——sow from 27 March
Swiss Chard——sow 27 March – 10 September
Thyme——sow 27 March – 22 July
Tomato20 February – 29 May13 April – 20 July4 May – 20 July
Turnip——sow 27 March – 12 September
Watercress——sow 27 March – 23 September
Watermelon28 March – 3 July25 April – 31 July16 May – 31 July
Zinniafrom 31 Marchfrom 5 Mayfrom 26 May
Zucchini4 April – 2 August25 April – 23 August16 May – 23 August

Planting out: a week after the last frost once the soil is warm enough for the crop; frost-hardy crops three weeks before it; an unheated greenhouse three weeks earlier. Seedlings are sown so they are ready on that day. Each window starts on the Greenly calendar date and ends on the last day that still leaves the crop’s days to harvest (from its card) before the average first autumn frost, plus six weeks of picking for crops harvested over weeks (tomatoes, peppers, aubergines, cucumbers, courgettes, pumpkins, watermelons, beans) — our rule; earlier in the window is safer.

When the soil warms up in Dayton

The day the top 7 cm of soil first averages each temperature over a week, median of 2016–2025 (ERA5 via Open-Meteo). The soil reaches 10 °C 24 days before the last spring frost and 15 °C 17 days after it.

SoilDateAgainst the last spring frost
5 °C15 February61 days earlier
10 °C24 March24 days earlier
15 °C4 May17 days later
18 °C16 May29 days later

Frost dates near Dayton

Of the nearest cities on our list, the last spring frost ends earliest in Cincinnati (11 April) and latest in Fort Wayne (24 April).

CityDistanceLast spring frostFirst autumn frost
Cincinnati75 km11 April9 November
Columbus104 km22 April2 November
Fort Wayne167 km24 April2 November
Indianapolis168 km14 April6 November
Frankfort183 km12 April3 November

Seeds, seedlings and markets in Dayton

Within 15 km of Dayton OpenStreetMap lists 9 garden centres, 1 market and 2 farm shops (collected 29 October 2026). The nearest garden centre to the city centre is Gardening Haven, 6 km away.

Places: © OpenStreetMap contributors, ODbL.

What to grow at home in winter in Dayton

Frosts in Dayton usually come from about 9 November to about 17 April. These plants have indoor care in their Greenly cards and are harvested quickly, so they can be sown on a windowsill in winter.

Weather in Dayton by month

Average weather in Dayton over 2016–2025: the warmest month is July. Months that average 20 °C or more by day: May–September (22.6–29.3 °C). Nights average below 0 °C in January (-4.6 °C), February (-2.5 °C) and December (-1.7 °C). About 1129 mm of rain falls in a year, on 137 days; May is the wettest month (125 mm) and September the driest (74 mm).

MonthDay, °CNight, °CRain, mmRainy days
January3.3-4.68511
February7.2-2.59711
March12.21.611513
April17.26.211213
May22.612.412516
June27.617.310212
July29.319.710414
August28.118.58411
September2615.7748
October19.39.6779
November11.22.5758
December6.3-1.77911

Average of the daily highs and lows, rain per month and days with at least 1 mm (ERA5 via Open-Meteo, the same grid cell as the frost dates).

Planted in autumn

CropWhen to plant
Bearded Irisby 10 October
Crocus10 October – 26 December
Daffodil10 October – 26 December
Garlic10 October – 26 December
Grape hyacinthby 10 October
Helleboreby 10 October
Hyacinth10 October – 26 December
Lilyby 10 October
Ornamental onionby 10 October
Peonyby 10 October
Saffronby 10 October
Snowdropby 10 October
Tulip10 October – 26 December
Wild garlicby 10 October

From a month before the first autumn frost, so the roots grow before winter, to the late-planting limit on each crop’s page (about two weeks before the ground freezes, by ten years of weather).