Greenly Garden

Last and first frost dates in Jeonju

South Korea

In Jeonju the last spring frost usually comes around 27 March and the first autumn frost around 17 November, which leaves about 235 frost-free days (median of 2016–2025). Tomato seedlings can go into open ground from 25 April to 28 July.

Last spring frostaround 27 March
First autumn frostaround 17 November
Frost-free days235 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 Jeonju?

The last frost in Jeonju usually comes around 27 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 6 March, while corn waits until 10 April. The first autumn frost follows around 17 November, about 235 days later: harvest or cover frost-tender crops before then.

When to sow and plant

CropSow for seedlingsPlant out in a greenhouseOpen ground
Achocha1 February – 9 August13 March – 18 September3 April – 18 September
Ageratumfrom 7 February—from 25 April
Arugula——sow 6 March – 13 October
Basil21 March – 15 September28 April – 23 October19 May – 23 October
Beet——sow 6 March – 18 September
Bell Pepper27 February – 29 May28 April – 28 July19 May – 28 July
Black-eyed Susanfrom 10 January—from 3 April
Bok Choy6 February – 26 September13 March – 31 October3 April – 31 October
Borage——sow 3 April – 23 September
Broad bean——sow 6 March – 9 August
Broccoli——sow 6 March – 2 August
Brussels Sprouts30 December – 30 June13 February – 14 August6 March – 14 August
Busy Lizziefrom 9 January—from 3 April
Cabbage——sow 6 March – 10 July
Calendula——sow from 6 March
Carrot——sow 6 March – 25 August
Cauliflower2 January – 2 August13 February – 13 September6 March – 13 September
Celeriac26 December – 30 May13 March – 15 August3 April – 15 August
Celery26 December – 9 June13 March – 25 August3 April – 25 August
Celosiafrom 27 Februaryfrom 13 Aprilfrom 4 May
Chamomile——sow 6 March – 13 September
Chayote22 December – 23 May20 March – 19 August10 April – 19 August
Chickpea——sow 6 March – 30 July
Chicory19 January – 24 August—6 March – 18 September
Chili Pepper27 February – 5 July28 April – 3 September19 May – 3 September
China asterfrom 7 Marchfrom 28 Aprilfrom 19 May
Chives——sow 6 March – 4 September
Cilantro——sow 6 March – 14 September
Corn——sow 10 April – 30 July
Corn poppy——sow from 6 March
Cosmosfrom 27 Februaryfrom 13 Aprilfrom 4 May
Cucumber31 March – 5 August28 April – 2 September19 May – 2 September
Daikon——sow 6 March – 11 September
Delphiniumfrom 16 December—from 6 March
Dill——sow 6 March – 24 September
Edging lobeliafrom 9 January—from 3 April
Eggplant27 February – 29 May28 April – 28 July19 May – 28 July
Florence fennel27 January – 9 August13 March – 23 September3 April – 23 September
Foxglovefrom 28 November—from 6 March
Garden sorrel——sow 6 March – 12 September
Green Beans——sow 4 May – 7 August
Hollyhock——sow from 6 March
Hyssop——sow 6 March – 5 August
Kale——sow 6 March – 6 September
Kiwano3 March – 12 August4 April – 13 September25 April – 13 September
Kohlrabi——sow 6 March – 16 September
Leek5 December – 21 May13 February – 30 July6 March – 30 July
Lemon balm——sow 6 March – 8 September
Lettuce——sow 6 March – 21 September
Lisianthusfrom 18 Novemberfrom 13 Februaryfrom 6 March
Lovage——sow from 6 March
Luffa17 March – 6 June28 April – 18 July19 May – 18 July
Marigoldfrom 30 Januaryfrom 13 Marchfrom 3 April
Marjoram27 February – 24 August—19 May – 23 October
Melon31 March – 23 July28 April – 20 August19 May – 20 August
Microgreens——sow 4 May – 3 November
Moringa24 March – 29 August18 May – 23 October8 June – 23 October
Moss rosefrom 16 January—from 3 April
Mustard greens——sow 6 March – 3 October
Napa cabbage8 February – 3 September13 March – 6 October3 April – 6 October
Nasturtiumfrom 3 Februaryfrom 13 Marchfrom 3 April
Okra17 March – 17 August28 April – 28 September19 May – 28 September
Oregano15 December – 14 August13 February – 13 October6 March – 13 October
Pansyfrom 19 Decemberfrom 13 Februaryfrom 6 March
Parsley——sow 6 March – 2 September
Parsnip——sow 6 March – 22 July
Peanut22 March – 13 July28 April – 19 August19 May – 19 August
Peas——sow 6 March – 4 September
Petuniafrom 24 Februaryfrom 28 Aprilfrom 19 May
Physalis18 February – 10 July4 April – 24 August25 April – 24 August
Pumpkin17 March – 11 June28 April – 23 July19 May – 23 July
Purple coneflowerfrom 13 December—from 6 March
Radish——sow 6 March – 18 October
Sage26 December – 10 August13 February – 28 September6 March – 28 September
Scarlet sagefrom 11 February—from 25 April
Snapdragonfrom 10 Decemberfrom 13 Februaryfrom 6 March
Soybean——sow 19 May – 29 August
Spinach——sow 6 March – 23 September
Stevia14 February – 1 July4 April – 19 August25 April – 19 August
Stock——sow from 6 March
Sunflower——sow from 4 May
Sweet alyssum——sow from 6 March
Sweet Corn28 February – 24 August22 March – 15 September12 April – 15 September
Sweet peafrom 2 Januaryfrom 13 Februaryfrom 6 March
Sweet William——sow from 6 March
Swiss Chard——sow 6 March – 18 September
Thyme——sow 6 March – 30 July
Tomato11 February – 6 June4 April – 28 July25 April – 28 July
Turnip——sow 6 March – 20 September
Watercress——sow 6 March – 1 October
Watermelon31 March – 11 July28 April – 8 August19 May – 8 August
Zinniafrom 13 Aprilfrom 18 Mayfrom 8 June
Zucchini7 April – 10 August28 April – 31 August19 May – 31 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 Jeonju

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 2 days after the last spring frost and 15 °C 29 days after it.

SoilDateAgainst the last spring frost
5 °C7 March20 days earlier
10 °C29 March2 days later
15 °C25 April29 days later
18 °C19 May53 days later

Frost dates near Jeonju

Of the nearest cities on our list, the last spring frost ends earliest in Daegu (19 March) and latest in Gwangju (1 April).

CityDistanceLast spring frostFirst autumn frost
Daejeon63 km1 April12 November
Gwangju77 km1 April23 November
Daegu131 km19 March21 November
Busan188 km19 March22 November
Seoul194 km29 March6 November

What to grow at home in winter in Jeonju

Frosts in Jeonju usually come from about 17 November to about 27 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 Jeonju by month

Average weather in Jeonju over 2016–2025: the warmest month is August. Months that average 20 °C or more by day: May–September (22.3–29.5 °C). Nights average below 0 °C in January (-4.6 °C), February (-3.2 °C) and December (-3 °C). About 1341 mm of rain falls in a year, on 124 days; July is the wettest month (267 mm) and January the driest (34 mm).

MonthDay, °CNight, °CRain, mmRainy days
January3.1-4.6346
February5.4-3.2446
March12.11.9659
April17.97.3869
May22.31210610
June26.317.115013
July28.721.726719
August29.522.123218
September25.417.617812
October1910.4858
November12.33.5557
December4.6-3397

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 18 October
Crocus18 October – 17 December
Daffodil18 October – 17 December
Garlic18 October – 17 December
Grape hyacinthby 18 October
Helleboreby 18 October
Hyacinth18 October – 17 December
Lilyby 18 October
Ornamental onionby 18 October
Peonyby 18 October
Saffronby 18 October
Snowdropby 18 October
Tulip18 October – 17 December
Wild garlicby 18 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).