January Weather in Ulsan, South Korea

Last updated: October 30, 2025

In January, Ulsan, South Korea experiences a diverse range of temperatures, with a maximum reaching 16°C (62°F) and a minimum dropping to -12°C (11°F). The average temperature hovers around 3°C (37°F), creating a chilly yet manageable winter atmosphere. The month sees an average precipitation of 32 mm (1.2 in) over just 3 days, making it a relatively dry period. Coupled with a humidity level of 72%, these weather conditions provide a unique experience for residents and visitors alike, ideal for exploring the city's winter landscapes and attractions.

January Temperature in Ulsan

In January, Ulsan, South Korea experiences notable winter chill, with temperatures dipping as low as -12°C (11°F) at night and a modest daytime average of around 3°C (37°F). The city sees a significant range, peaking at a mild 16°C (62°F), hinting at the gradual warming that lies ahead. As the month progresses, a slight upward trend emerges, evidenced by February's warmer nights and days averaging 4°C (40°F). This early glimpse of spring leads into March, where temperatures continue to rise, moving from chilly lows to a much more pleasant average of 9°C (49°F). Overall, January sets the stage for a shift in seasons, bridging the stark cold of winter with the promise of a warming trend in the coming months.

January Weather in Ulsan: Daily Temperature Highs, Lows, and Averages

The chart illustrates January temperature patterns in Ulsan, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Ulsan, January typically has an average temperature of 3°C (37°F), with highs reaching up to 16°C (62°F) and lows dropping to around -12°C (11°F).
JanFebMarAprMayJunJulAugSepOctNovDec374049576671788172635239
Data source: Temperature data for Ulsan generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

January Precipitation in Ulsan

In Ulsan, South Korea, January marks the beginning of the year with relatively low precipitation, totaling 32 mm (1.2 in) over just three days. This trend of light rains continues into February, where the overall precipitation slightly increases to 39 mm (1.5 in) but still remains manageable. As spring approaches, March and April see a noticeable uptick, with 86 mm (3.4 in) and 87 mm (3.4 in) respectively, indicating a shift toward wetter conditions. The trend escalates dramatically in the summer months, particularly in July, where precipitation peaks at 244 mm (9.6 in) across 14 days. This pattern clearly establishes January as the driest month, contrasting sharply with the deluge of summer, highlighting how Ulsan's climate transitions from mild winter dryness to a vibrant, rain-soaked summer.

January Precipitation Trends in Ulsan

The chart displays monthly precipitation patterns in Ulsan, with values for each month alongside January’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how January’s conditions compare to those of other months. In Ulsan, January typically receives around 32 mm (1.2 inches) of precipitation spread over approximately 3 days.
JanFebMarAprMayJunJulAugSepOctNovDec32398687801442441992361002123
Data source: Precipitation data for January generated using information from the Copernicus Climate Change Service.
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January Humidity in Ulsan

In January, Ulsan, South Korea, experiences a noteworthy humidity level of 72%, setting the stage for a damp winter. As the months roll on, humidity gradually decreases to 67% in February and further to 65% in March, suggesting a more comfortable atmosphere as spring approaches. However, this trend is short-lived, as humidity spikes once again, reaching 75% in April and continuing to rise dramatically through the summer months, peaking at a staggering 95% in July. The city then sees a slight decline, with humidity levels hovering around 80% in September before gradually reverting to the cooler ranges of 77% in October and 75% in November. As the year wraps up in December, humidity remains relatively high at 73%, indicating Ulsan's distinct seasonal rhythm of moisture that shapes its climate throughout the year.

January Average Humidity in Ulsan

This chart illustrates the average monthly humidity levels in Ulsan, with January’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In January, average humidity in Ulsan is approximately 72%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec73%67%65%75%83%87%95%93%80%77%75%73%
Data source: Humidity data for January generated using information from the Copernicus Climate Change Service.

January UV Index in Ulsan

In January, Ulsan experiences a UV Index of 3, placing it in the moderate exposure category, which means you can expect a burn time of about 30 minutes under the sun. As the months progress, the UV Index starts to climb, peaking at a dramatic 12 in both July and August, indicating an extreme risk of harm from unprotected sun exposure, with burn times shrinking to just 10 minutes. This upward trend continues into the spring, where March hits a 7 (high) and April and May soar to 10 (very high). Notably, the year's beginning and end maintain a similar low UV Index of 3 to 5, making those months safer for outdoor activities without excessive sun protection. As you plan your outings, remember to keep an eye on the UV Index to stay safe while enjoying Ulsan's beautiful weather. For more information on UV levels throughout the year, check out Ulsan UV Index.

Maximum UV Index Levels in Ulsan for January

The chart shows the monthly maximum UV Index (UVI) for Ulsan in January, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In January, the maximum UV index in Ulsan typically reaches 3, which falls under the moderate exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec357101011121210753
Data source: Ulsan January UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

January Sunshine in Ulsan

In Ulsan, South Korea, January ushers in the year with 197 hours of sunshine, a modest start that sets the stage for a gradual increase as the seasons transition. As February and March roll in, the days lengthen, yielding 242 and 272 hours of sunlight respectively, while April reaches a delightful high of 284 hours. The sun continues to shine brightly into the vibrant month of May, peaking at 307 hours, making it the sunniest month of the year. Even during the summer months of June and July, sunshine remains plentiful with 306 and 283 hours respectively, before dipping slightly in August. As the year progresses into autumn, sunshine hours gradually decline, leading to a steady rhythm of 299 hours in August, followed by 248 in September and 238 in November. By December, Ulsan wraps up the year with 244 hours of daylight, reflecting a seasonal cycle that embraces both the warmth and variation of sunshine throughout the year.

Monthly Sunshine Duration in Ulsan: January Highlighted

The January sunshine duration represents the total number of hours Ulsan experiences direct sunlight during the month of January, excluding cloudy or obstructed periods. This chart compares the sunshine duration of January with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec197h242h272h284h307h306h283h299h248h259h238h244h
Data source: Ulsan January Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Ulsan During January

January in Ulsan, South Korea, boasts a 61% chance of sunny weather, making it one of the brighter months as the year begins. This favorable outlook stands out, especially when compared to the following month, February, which sees a slight dip to 58%. As winter progresses into the spring months, the likelihood of sunshine fluctuates, with March and April dropping to 38% and 44%, respectively. Interestingly, the trend shows that sunny days become scarcer as summer approaches, peaking in June with just 27% sunshine likelihood. However, there is a notable resurgence in sun-soaked days as the year concludes, culminating in 77% sunshine in December, setting the stage for an inviting holiday season.

Percentage of Sunny Days in January in Ulsan

The chart illustrates the percentage of sunny days in Ulsan throughout the year, with January highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often Ulsan experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec61%58%38%44%39%27%20%24%28%52%70%77%
Data source: Ulsan January chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Ulsan in January

In Ulsan, South Korea, January welcomes 10 hours of daylight, a trend that continues into February with the same duration. As spring approaches in March, daylight increases to 11 hours, paving the way for the longer, sun-filled days of April and May, which boast 13 and 14 hours, respectively. This peak daylight duration remains consistent through June and July, offering 14 hours of sunlight for outdoor activities and exploration. However, as summer wanes into August, daylight begins to taper, dropping to 13 hours. The transition into autumn sees a gradual decline, with September enjoying 12 hours, followed by November and December, where daylight dwindles to 10 and 9 hours. This cyclical rhythm highlights the seasonal shifts in Ulsan, making each month a unique experience in the interplay of light and dark.

Average Daylight Hours in Ulsan for January

The chart illustrates the variation in daylight duration in Ulsan throughout the year, with January highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec10h 3m10h 53m11h 58m13h 5m14h 1m14h 29m14h 15m13h 26m12h 22m11h 15m10h 17m9h 47m
Data source: Ulsan daylight hours, calculated by summing the hours between sunrise and sunset for each day.

January Winds in Ulsan

In Ulsan, South Korea, the January winds arrive with a brisk average speed of 3.8 m/s (9 mph), setting the tone for the winter season. This wind speed remains consistent with February, suggesting a relatively stable start to the year. As spring approaches, however, a gradual decline is observed, with March and April recording slightly calmer winds at 3.3 m/s (7 mph). This gentle decrease continues into May, where the winds soften further to 3.0 m/s (7 mph). Interestingly, the summer months see a slight uptick, with July and August maintaining low winds around 2.8-2.9 m/s (6 mph), creating a tranquil atmosphere as temperatures rise. As autumn sets in, September heralds a return to more vigorous breezes at 3.6 m/s (8 mph) before tapering off once again in the cooler months of October and November. By December, the winds pick up slightly to 3.7 m/s (8 mph), rounding out the year with a subtle reminder of the strength of winter’s breath. Overall, Ulsan's wind patterns reflect a distinct seasonal rhythm, transitioning from the energetic gusts of winter to the calming breezes of summer and back again.

Average January Wind Speed in Ulsan

The chart displays monthly wind speed patterns in Ulsan, with values for each month shown alongside January's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how January's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec3.8 m/s3.83.33.33.02.62.82.93.62.93.13.7
Data source: Ulsan January wind data, generated using information from the Copernicus Climate Change Service.

How January Weather in Ulsan Compares to Other Months

Weather in Ulsan varies notably across the year, with each month offering distinct climate conditions. This page compares January’s weather to other months in Ulsan, focusing on differences in temperature, rainfall, humidity, and UV levels.

In January, the weather features a minimum temperature of -12°C (11°F) and an average of 3°C (37°F), with a maximum reaching 16°C (62°F). The month experiences 32 mm (1.2 in) of precipitation over three days, accompanied by a humidity level of 72%. Conversely, February sees a slight increase in warmth, with minimum temperatures around -9°C (15°F) and an average of 4°C (40°F), peaking at 23°C (73°F). Precipitation rises slightly to 39 mm (1.5 in) over four days, while humidity decreases to 67%. For more details on February weather, check Ulsan weather in February.

January weather in Ulsan is characterized by colder temperatures, with a minimum of -12°C (11°F) and an average around 3°C (37°F). This winter month experiences limited precipitation, totaling 32 mm (1.2 in) over just three days, and the humidity remains relatively high at 72%. In contrast, March marks the onset of spring, with a significant increase in temperatures, reaching a minimum of -2°C (29°F) and averaging 9°C (49°F), peaking at 22°C (73°F). However, March also brings increased rainfall, with 86 mm (3.4 in) spread over eight days and a decrease in humidity to 65%. For more details on March weather, you can check Ulsan weather in March.

In January, temperatures range from a chilly -12°C (11°F) to a mild 16°C (62°F), with an average of 3°C (37°F). The month sees limited precipitation, with only 32 mm (1.2 in) over three days and a humidity level of 72%. In contrast, April experiences a substantial warm-up, with temperatures varying from 2°C (35°F) to a high of 26°C (80°F), and an average of 14°C (57°F). Rainfall increases significantly to 87 mm (3.4 in) across seven days, accompanied by slightly higher humidity at 75%. This notable shift in weather signifies the transition into spring. For more detailed information, check out Ulsan weather in April.

January weather features a chilly atmosphere, with temperatures ranging from a minimum of -12°C (11°F) to a maximum of 16°C (62°F), averaging around 3°C (37°F). The month sees limited precipitation of 32 mm (1.2 in) over just 3 days, accompanied by a moderate humidity level of 72%. In contrast, May brings a dramatic shift with warmer temperatures, ranging from a low of 6°C (43°F) to a high of 33°C (92°F), and an average temperature of 19°C (66°F). This month also experiences significantly higher rainfall, totaling 80 mm (3.1 in) over 8 days, along with increased humidity at 83%. For more detailed information, you can check Ulsan weather in May.

In January, the weather is crisp and cold, with temperatures ranging from a chilly -12°C (11°F) at night to a mild maximum of 16°C (62°F) during the day. The month typically sees around 32 mm (1.2 in) of precipitation over just three days, accompanied by a humidity level of 72%. In sharp contrast, June brings warmth and humidity, with temperatures soaring from a minimum of 13°C (56°F) to a maximum of 32°C (90°F). June experiences significantly higher precipitation at 144 mm (5.7 in) spread over approximately ten days, and the increased humidity reaches 87%. For more details about the June weather in Ulsan, check out Ulsan weather in June.

January and July present starkly contrasting weather patterns. In January, temperatures range from a chilly -12°C (11°F) to a mild 16°C (62°F), with an average of 3°C (37°F). Precipitation is relatively low, with only 32 mm (1.2 in) spread over 3 days, and humidity sits at a comfortable 72%. In contrast, July brings sweltering heat, with minimum temperatures starting at 17°C (63°F) and soaring to a maximum of 36°C (98°F), resulting in an average of 26°C (78°F). The month is also characterized by heavy rainfall, totaling 244 mm (9.6 in) over 14 days, coupled with high humidity levels of 95%. For more detailed information on July weather, you can visit Ulsan weather in July.

The weather in January and August presents a striking contrast in Ulsan. January experiences much colder temperatures, with a minimum of -12°C (11°F) and an average of 3°C (37°F), while August sees a warm minimum of 19°C (66°F) and an average of 27°C (81°F). Precipitation also differs significantly; January averages only 32 mm (1.2 in) across three days, whereas August brings substantial rainfall of 199 mm (7.8 in) over 15 days. Additionally, humidity levels climb in August to a muggy 93%, compared to January's 72%. For more details, you can check Ulsan weather in August.

The weather in January and September presents a stark contrast, showcasing the seasonal shifts experienced in many regions. In January, temperatures can drop as low as -12°C (11°F), with an average around 3°C (37°F) and highs reaching 16°C (62°F). This month experiences relatively low precipitation, totaling 32 mm (1.2 in) over just 3 days, alongside a humidity level of 72%. In contrast, September offers a much warmer climate with minimum temperatures of 13°C (56°F) and average highs of 30°C (87°F), leading to a more pleasant atmosphere. This month is marked by increased rainfall, with 236 mm (9.3 in) of precipitation spread across 12 days and humidity rising to 80%. For more details, check out the Ulsan weather in September.

January and October present very different weather experiences. January typically features colder temperatures, with a minimum of -12°C (11°F), an average of 3°C (37°F), and a maximum of 16°C (62°F). It is also relatively dry, receiving about 32 mm (1.2 in) of precipitation over just 3 days, accompanied by a humidity level of 72%. In contrast, October enjoys much milder conditions, with temperatures ranging from a minimum of 5°C (41°F) to a pleasant maximum of 30°C (85°F) and an average of 17°C (63°F). However, October is also wetter, with 100 mm (3.9 in) of rain spread across 7 days and a slightly higher humidity of 77%. For more specific details on October's weather, you can check Ulsan weather in October.

January weather is notably colder than November, with temperatures ranging from a minimum of -12°C (11°F) to a maximum of 16°C (62°F). In contrast, November showcases a milder climate with temperature variations between -2°C (29°F) and 22°C (72°F). While both months experience similar levels of precipitation, January receives slightly more at 32 mm (1.2 in) compared to November's 21 mm (0.8 in), and the humidity is relatively high in both months, reaching 72% in January and 75% in November. To learn more about November's weather specifics, you can check this link: Ulsan weather in November.

In January, the weather tends to be colder than in December, with minimum temperatures plummeting to -12°C (11°F) compared to December's minimum of -9°C (17°F). Although the average temperatures for both months are quite similar, January features a slightly lower average of 3°C (37°F), while December sees a milder average of 4°C (40°F). Precipitation is slightly higher in January at 32 mm (1.2 in), compared to December's 23 mm (0.9 in), though both months share the same frequency of precipitation over three days. The humidity remains relatively stable, with January at 72% and December at 73%. For more detailed information, visit Ulsan weather in December.

Compare Ulsan's Climate with Cities Worldwide

Conclusion: What to Expect From January Weather in Ulsan

January in Ulsan showcases a distinct shift from the milder months of autumn and the warmth of summer, plunging to cooler temperatures and clearer skies. While daytime highs can reach a pleasant 16°C, the average dips to 3°C, and even plunges to a chilly -12°C overnight. With only a few days of precipitation, January remains relatively dry compared to the wetter months ahead, making it a great time for those who prefer a crisp, invigorating atmosphere. The 72% humidity adds a touch of winter's bite, setting Ulsan apart from the milder, more humid conditions of other seasons. For a deeper dive into the weather patterns throughout the year, visit Ulsan Climate.