Greenly Garden
Get the app
EN

Last and first frost dates in Dundalk

Ireland

In Dundalk the last spring frost usually comes around 20 March and the first autumn frost around 20 November, which leaves about 245 frost-free days (median of 2016–2025). Tomato seedlings can go into open ground from 14 June to 31 July.

Last spring frostaround 20 March
First autumn frostaround 20 November
Frost-free days245 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 Dundalk?

The last frost in Dundalk usually comes around 20 March: 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 February, while corn waits until 15 May. The first autumn frost follows around 20 November, about 245 days later: harvest or cover frost-tender crops before then.

When to sow and plant

CropSow for seedlingsPlant out in a greenhouseOpen ground
Achocha26 February – 12 August7 April – 21 September28 April – 21 September
Ageratumfrom 29 March—from 14 June
Arugula——sow 27 February – 16 October
Basil19 May – 18 September26 June – 26 October17 July – 26 October
Beet——sow 27 February – 21 September
Bell Pepper27 April – 1 June26 June – 31 July17 July – 31 July
Black-eyed Susanfrom 4 February—from 28 April
Bok Choy3 March – 29 September7 April – 3 November28 April – 3 November
Borage——sow 27 March – 26 September
Broad bean——sow 27 February – 12 August
Broccoli——sow 27 February – 5 August
Brussels Sprouts23 December – 3 July6 February – 17 August27 February – 17 August
Busy Lizziefrom 2 January—from 27 March
Cabbage——sow 27 February – 13 July
Calendula——sow from 27 February
Carrot——sow 27 February – 28 August
Cauliflower26 December – 5 August6 February – 16 September27 February – 16 September
Celeriac20 January – 2 June7 April – 18 August28 April – 18 August
Celery20 January – 12 June7 April – 28 August28 April – 28 August
Celosiafrom 14 Aprilfrom 29 Mayfrom 19 June
Chamomile——sow 27 February – 16 September
Chayote26 January – 26 May24 April – 22 August15 May – 22 August
Chickpea——sow 27 February – 2 August
Chicory12 January – 27 August—27 February – 21 September
Chili Pepper27 April – 8 July26 June – 6 September17 July – 6 September
China asterfrom 5 Mayfrom 26 Junefrom 17 July
Chives——sow 27 February – 7 September
Cilantro——sow 27 February – 17 September
Corn——sow 15 May – 2 August
Corn poppy——sow from 27 February
Cosmosfrom 14 Aprilfrom 29 Mayfrom 19 June
Cucumber29 May – 8 August26 June – 5 September17 July – 5 September
Daikon——sow 27 February – 14 September
Delphiniumfrom 9 December—from 27 February
Dill——sow 27 February – 27 September
Edging lobeliafrom 3 February—from 28 April
Eggplant27 April – 1 June26 June – 31 July17 July – 31 July
Florence fennel21 February – 12 August7 April – 26 September28 April – 26 September
Foxglovefrom 21 November—from 27 February
Garden sorrel——sow 27 February – 15 September
Green Beans——sow 19 June – 10 August
Hollyhock——sow from 27 February
Hyssop——sow 27 February – 8 August
Kale——sow 27 February – 9 September
Kiwano22 April – 15 August24 May – 16 September14 June – 16 September
Kohlrabi——sow 27 February – 19 September
Leek28 November – 24 May6 February – 2 August27 February – 2 August
Lemon balm——sow 27 February – 11 September
Lettuce——sow 27 February – 24 September
Lisianthusfrom 11 Novemberfrom 6 Februaryfrom 27 February
Lovage——sow from 27 February
Luffa15 May – 9 June26 June – 21 July17 July – 21 July
Marigoldfrom 24 Februaryfrom 7 Aprilfrom 28 April
Marjoram27 April – 27 August—17 July – 26 October
Melon29 May – 26 July26 June – 23 August17 July – 23 August
Microgreens——sow 19 June – 6 November
Moringa7 May – 1 September1 July – 26 October22 July – 26 October
Moss rosefrom 9 January—from 27 March
Mustard greens——sow 27 February – 6 October
Napa cabbage5 March – 6 September7 April – 9 October28 April – 9 October
Nasturtiumfrom 28 Februaryfrom 7 Aprilfrom 28 April
Okra15 May – 20 August26 June – 1 October17 July – 1 October
Oregano8 December – 17 August6 February – 16 October27 February – 16 October
Pansyfrom 12 Decemberfrom 6 Februaryfrom 27 February
Parsley——sow 27 February – 5 September
Parsnip——sow 27 February – 25 July
Peanut20 May – 16 July26 June – 22 August17 July – 22 August
Peas——sow 27 February – 7 September
Petuniafrom 24 Aprilfrom 26 Junefrom 17 July
Physalis9 April – 13 July24 May – 27 August14 June – 27 August
Pumpkin15 May – 14 June26 June – 26 July17 July – 26 July
Purple coneflowerfrom 6 December—from 27 February
Radish——sow 27 February – 21 October
Sage19 December – 13 August6 February – 1 October27 February – 1 October
Scarlet sagefrom 2 April—from 14 June
Snapdragonfrom 3 Decemberfrom 6 Februaryfrom 27 February
Soybean——sow 17 July – 1 September
Spinach——sow 27 February – 26 September
Stevia5 April – 4 July24 May – 22 August14 June – 22 August
Stock——sow from 27 February
Sunflower——sow from 19 June
Sweet alyssum——sow from 27 February
Sweet Corn13 April – 27 August5 May – 18 September26 May – 18 September
Sweet peafrom 26 Decemberfrom 6 Februaryfrom 27 February
Sweet William——sow from 27 February
Swiss Chard——sow 27 February – 21 September
Thyme——sow 27 February – 2 August
Tomato2 April – 9 June24 May – 31 July14 June – 31 July
Turnip——sow 27 February – 23 September
Watercress——sow 27 February – 4 October
Watermelon29 May – 14 July26 June – 11 August17 July – 11 August
Zinniafrom 27 Mayfrom 1 Julyfrom 22 July
Zucchini5 June – 13 August26 June – 3 September17 July – 3 September

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 Dundalk

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 39 days after the last spring frost and 15 °C 86 days after it.

SoilDateAgainst the last spring frost
5 °Calready in the first week of January—
10 °C28 April39 days later
15 °C14 June86 days later
18 °C17 July119 days later

Frost dates near Dundalk

Of the nearest cities on our list, the last spring frost ends earliest in Bray (29 January) and latest in Belfast (18 April).

CityDistanceLast spring frostFirst autumn frost
Navan43 km28 March20 November
Dublin73 km7 April24 November
Belfast73 km18 April19 November
Mullingar82 km19 March23 November
Bray91 km29 January7 December

Seeds, seedlings and markets in Dundalk

Within 15 km of Dundalk OpenStreetMap lists 2 garden centres, 2 farm-supply shops and 2 farm shops (collected 28 October 2026). The nearest farm supply to the city centre is Hardys, 2 km away.

Places: © OpenStreetMap contributors, ODbL.

What to grow at home in winter in Dundalk

Frosts in Dundalk usually come from about 20 November to about 20 March. 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 Dundalk by month

Average weather in Dundalk over 2016–2025: the warmest month is July. No month averages 20 °C by day; the warmest, July, reaches 19 °C. No month averages below 0 °C at night; the coldest nights, in January, average 2.5 °C. About 1013 mm of rain falls in a year, on 170 days; September is the wettest month (103 mm) and May the driest (62 mm).

MonthDay, °CNight, °CRain, mmRainy days
January7.62.56613
February8.63.27714
March103.58115
April11.64.86813
May15.37.96212
June17.610.68615
July1912.18815
August18.7129815
September16.510.110315
October13.58.29815
November1059114
December8.43.89514

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 21 October
Crocus21 October – end of December
Daffodil21 October – end of December
Garlic21 October – end of December
Grape hyacinthby 21 October
Helleboreby 21 October
Hyacinth21 October – end of December
Lilyby 21 October
Ornamental onionby 21 October
Peonyby 21 October
Saffronby 21 October
Snowdropby 21 October
Tulip21 October – end of December
Wild garlicby 21 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).