Last and first frost dates in Ulsan

When is the last frost in Ulsan?

The last frost in Ulsan usually comes around 22 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 1 March, while corn waits until 4 April. The first autumn frost follows around 16 November, about 239 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 Ulsan

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 31 days after it.

Frost dates near Ulsan

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

Seeds, seedlings and markets in Ulsan

Within 15 km of Ulsan OpenStreetMap lists 1 garden centre, 8 markets and 1 farm shop (collected 28 October 2026). The nearest garden centre to the city centre is 조운어바웃플랜츠, 12 km away.

• 조운어바웃플랜츠 — garden centre
  서진3길 22, 44109 울산광역시 · 12 km
• 전하시장 — market
  녹수1길(Noksu 1-gil) 6, 울산광역시 · 11 km
• 월봉시장(Wolbong Market) — market
  화정6길 16, 울산광역시 · 11 km

• Where to buy seeds and seedlings in Ulsan

Places: © OpenStreetMap contributors, ODbL.

Weather in Ulsan by month

Average weather in Ulsan over 2016–2025: the warmest month is August. Months that average 20 °C or more by day: May–October (20–29.7 °C). Nights average below 0 °C in January (-3.5 °C), February (-1.7 °C) and December (-2.5 °C). About 1521 mm of rain falls in a year, on 111 days; September is the wettest month (268 mm) and December the driest (34 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).