Seoul's streak of 17 consecutive tropical nights ended on July 9, 2025, as overnight temperatures finally dropped [1].
The break in the heatwave provides critical relief for a city that has struggled with extreme temperatures and humidity. Persistent tropical nights, where temperatures remain high enough to disrupt sleep and health, often exacerbate the physical toll of daytime heat.
On the morning of July 9, 2025, the city recorded a low temperature of 24°C [1]. This dip broke a cycle of 17 consecutive nights where the temperature failed to drop sufficiently [1]. During the height of the heatwave, peak daytime temperatures reached around 40°C [1].
While the streak has ended, the overall monthly data indicates a severe summer. Seoul recorded 22 tropical nights in total throughout July 2025 [2]. This frequency highlights the intensity of the region's current climate patterns.
Weather officials said the extreme heatwave eased slightly, which allowed the overnight lows to fall. However, the relief may be temporary. Experts said the indirect effects of recent typhoons are expected to increase weather variability in the coming days [1].
Residents have faced a grueling combination of high humidity and extreme heat. The transition from daytime peaks of 40°C [1] to nights that refused to cool down created a sustained environment of thermal stress for the population.
“Seoul's streak of 17 consecutive tropical nights ended on July 9, 2025”
The occurrence of 22 tropical nights in a single month indicates a significant shift in urban climate patterns for Seoul. The intersection of extreme heatwaves and the influence of typhoons suggests an increase in weather volatility, where brief periods of relief are offset by higher peak temperatures and unpredictable precipitation.
