April 17 forecasts predict cooler temperatures and improved air quality with rainfall in many regions.
Category: Climate & Environment
On April 17, 2026, South Korea is experiencing a welcome break from the early summer heat as rain falls across the Chungcheong and southern regions, including Jeju Island. This change in weather is expected to provide some relief from the soaring temperatures that have characterized the week.
In Seoul, temperatures are forecasted to reach a high of 20 degrees Celsius (68 degrees Fahrenheit) after starting the day at a low of 14 degrees Celsius (57 degrees Fahrenheit). The air quality in the capital is expected to remain at a moderate level, with fine dust levels categorized as "ordinary." Meanwhile, cities like Chuncheon and Gangneung report even more favorable conditions, with fine dust levels deemed "good" and temperatures peaking at 20 degrees Celsius (68 degrees Fahrenheit) and 19 degrees Celsius (66 degrees Fahrenheit), respectively.
In Daejeon and Cheongju, the weather is similar, with lows around 11 degrees Celsius (52 degrees Fahrenheit) and highs reaching 19 degrees Celsius (66 degrees Fahrenheit). The southern city of Daegu is slightly cooler, with a forecasted high of 18 degrees Celsius (64 degrees Fahrenheit) and a low of 8 degrees Celsius (46 degrees Fahrenheit). This pattern of cooler temperatures is echoed in Gwangju and Jeonju, where highs are expected to be 17 and 19 degrees Celsius (63 and 66 degrees Fahrenheit), respectively.
Busan and Jeju Island are also experiencing similar weather patterns, with highs around 19 degrees Celsius (66 degrees Fahrenheit) and lows of 12 and 14 degrees Celsius (54 and 57 degrees Fahrenheit). The rain that is expected to fall today is anticipated to alleviate the dry conditions that have persisted, especially in areas like Daegu and Gyeongbuk, where dry weather advisories have been in effect.
According to reports from Air Korea, the nationwide fine dust levels on April 17 are fluctuating between "good" and "ordinary". In the western regions, there was a temporary spike in dust levels during the morning and evening hours due to a combination of residual pollutants and locally generated fine dust. Fortunately, as the day progresses, vertical mixing in the atmosphere is expected to help lower these levels again.
"The influence of rain has a cleansing effect, washing away airborne particles and improving air quality across many areas," a meteorologist noted. This is particularly evident in regions where rain is forecasted to fall, resulting in a more favorable average air quality index.
Looking ahead to April 18, the national average for fine dust levels is again expected to range from "good" to "ordinary." Nonetheless, central regions may see a rise in dust levels during the morning and evening due to stagnant air conditions, which can lead to a buildup of pollutants. The pattern of air stagnation followed by dispersal is typical for spring, highlighting the dynamic nature of air quality during this transitional season.
On the other hand, ozone levels are projected to remain at a "normal" level across the country on April 17, with conditions not conducive for the formation of high ozone concentrations. This is largely due to a lack of strong sunlight and high temperatures, which are necessary for ozone generation. Yet, on April 18, parts of the midwestern region, including northern and southern Gyeonggi, as well as Chungbuk and Chungnam, are predicted to experience "bad" ozone levels, particularly during the afternoon when sunlight is most intense.
In Daegu, the forecast calls for a high of 18 degrees Celsius (64 degrees Fahrenheit) on April 17, slightly lower than the previous days, with morning temperatures hovering around 10 degrees Celsius (50 degrees Fahrenheit). Rainfall is expected to be substantial, with up to 20 millimeters (0.79 inches) anticipated in the southern regions, and 5 millimeters (0.20 inches) in northern areas of Gyeongbuk.
As the week progresses, the heat is expected to return, with Daegu's temperatures projected to rise again to 27 degrees Celsius (81 degrees Fahrenheit) by April 18, continuing the trend of early summer weather that has dominated the region. This pattern of fluctuating temperatures highlights the variability of springtime weather in South Korea, where warm spells can quickly switch to cooler, rainy conditions.
As South Koreans prepare for the upcoming warmer days, experts recommend staying hydrated and taking precautions against UV exposure, especially with the anticipated high UV index during sunny afternoons. The return of warm weather will likely see a resurgence in outdoor activities, making it important for individuals to remain aware of their surroundings and the changing weather conditions.
In a nutshell, the April 17 weather brings a refreshing change for many, with rain providing relief from the heat and improving air quality across much of South Korea. As the country transitions into warmer weather, residents are advised to stay informed about the daily forecasts and take necessary precautions to enjoy the spring season safely.