Central South Korea faces a forecast of extreme rainfall reaching up to 80 mm per hour [1].

Understanding these specific measurements is critical for public safety, as different hourly rates correlate directly to the severity of flooding and the failure of standard protective gear.

Reporter Choi Ah-young of YTN said how rainfall intensity impacts daily life and infrastructure. According to the report, when rain reaches 15 mm per hour, windshield wipers must run continuously and water begins to pool on roads [2].

As the intensity increases to 30 mm per hour, the utility of umbrellas diminishes [2]. Choi said, "When it exceeds 30mm per hour, using an umbrella becomes meaningless."

The risk to life and property escalates quickly beyond that point. Significant flood risks begin to materialize once rainfall hits 50 mm per hour [2].

When the rate exceeds 70 mm per hour, the weather is classified as "extreme heavy rain," a level where flood damage becomes a reality [2]. Choi said, "When it exceeds 70mm per hour, it is considered 'extreme heavy rain,' and flooding damage becomes a reality."

These warnings were issued on July 4, 2026, to prepare the public for the upcoming weekend and holidays [1]. The central region remains the primary area of concern as officials encourage residents to monitor rainfall rates closely to avoid being trapped by sudden urban flooding.

“When it exceeds 30mm per hour, using an umbrella becomes meaningless.”

By breaking down rainfall into hourly thresholds, authorities are shifting from general weather warnings to actionable risk assessments. This allows citizens to recognize the immediate danger of 'extreme heavy rain'—defined here as 70 mm per hour—which typically overwhelms urban drainage systems and leads to rapid flash flooding.