Ulsan Temperature by Month

The average annual maximum temperature in Ulsan, Chungcheongbuk-Do, South Korea is 20°C (68°F), with daytime highs ranging from 8°C (46°F) in January to 30°C (86°F) in August. This page covers monthly averages, day-night differences, and how Ulsan compares to cities worldwide.

Visitors to Ulsan can expect significant temperature changes throughout the year. Nighttime temperatures also vary widely, ranging from 24°C (75°F) in August to -1°C (30°F) in January.

The chart below illustrates the average maximum day and minimum night temperatures in Ulsan by month:

From around 4 AM to 6 AM temperatures are at their lowest; by 3 PM they've climbed to their daily peak. August, the warmest month, averages 169 hours of sunshine.

The chart below shows the average temperature throughout the year:

Ulsan's average annual maximum temperature is 20°C (68°F). To put that in context, here's how it compares to a few well-known destinations:

Seville, Spain averages 23°C (73°F) a year, one of the warmer cities in Western Europe, with long hot summers.

Reykjavík, Iceland averages 9°C (48°F) a year, mild summers by Icelandic standards, but cold winters and frequent wind.

Boston, USA averages 16°C (61°F) annually, with four distinct seasons and cold winters that rival northern Europe.

Adelaide, Australia averages 21°C (70°F) a year, with warm summers, mild winters, and relatively low rainfall year-round.

Temperature alone doesn't tell the whole story, humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.

In the cooler months, when temperatures drop below 10°C, high humidity makes the cold feel more cutting than it would in dry conditions.

In Ulsan, January is the coolest month, with average highs of 8°C (46°F) and humidity around 48%, considered moderate. In August, the warmest month, temperatures average 30°C (86°F) with 77% humidity, conditions that feel high. For a full picture, see our humidity page.

Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.

The readings come from a range of sources, land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.

Seasonal temperature shifts influence more than just how warm it feels, they also drive changes in rainfall, cloud cover, and wind patterns throughout the year.

Warmer air holds more moisture, which tends to mean heavier or more frequent rain during the warmer months. When temperatures drop in winter, any precipitation that does fall is more likely to come as snow or sleet, though in Ulsan this rarely lasts long on the ground.

For more on Ulsan's weather, including monthly rainfall, sunshine hours, and humidity, visit our Ulsan climate page.