Last and first frost dates in Seoul

When is the last frost in Seoul?

The last frost in Seoul usually comes around 29 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 8 March, while corn waits until 10 April. The first autumn frost follows around 6 November, about 222 days later: harvest or cover frost-tender crops before then.

When to sow and plant

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 Seoul

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 3 days after the last spring frost and 15 °C 26 days after it.

Frost dates near Seoul

Of the nearest cities on our list, the last spring frost ends earliest in Gangneung (19 March) and latest in Chuncheon (6 April).

Seeds, seedlings and markets in Seoul

Within 15 km of Seoul OpenStreetMap lists 1 garden centre, 2 plant nurseries and 85 markets (collected 28 October 2026). The nearest garden centre to the city centre is 방실농원, 13 km away.

• 방실농원 — garden centre
  동구릉로53번길 227-11, 11911 구리시 · 13 km
• Tongin Market — market
  자하문로15길 18, 03036 서울특별시 · 3 km
• Mangwon Market — market
  Mon–Sun 09:00–21:00 · 7 km
• 증산종합시장 — market
  증산로3길 12, 03500 서울특별시 · 8 km
• Local street market — market
  동일로143길, 서울특별시 · 9 km
• Inheon Marketplace — market
  인헌6길 16 농, 서울특별시 · 10 km

• Where to buy seeds and seedlings in Seoul

Places: © OpenStreetMap contributors, ODbL.

Weather in Seoul by month

Average weather in Seoul over 2016–2025: the warmest month is August. Months that average 20 °C or more by day: May–September (22.7–29.5 °C). Nights average below 0 °C in January (-7.1 °C), February (-5 °C) and December (-5.6 °C). About 1271 mm of rain falls in a year, on 101 days; July is the wettest month (310 mm) and January the driest (18 mm).

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

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).