The Korea Meteorological Administration announced that this summer (June–August) recorded the highest average temperatures since national records began in 1973.

The national average temperature reached 25.7°C, edging past last year’s 25.7 °C and setting a new record.

The season’s daily average high was 30.7°C, the highest on record, while the daily average low was 21.5°C, the second highest. The average nighttime low between 6:01 pm and 9:00 am was 21.9°C, tying with 2024 but ranked first due to its recency.

Heat wave days, defined as days with highs of 33 degrees or above, averaged 28.1 days, third only to 2018 (31.0) and 1994 (28.5).

Tropical nights, when lows stay at 25 degrees or higher, averaged 15.5 days, placing fourth behind 2024 (20.2), 2018 (16.5), and 1994 (16.5).

The findings confirm that 2025 has been the hottest summer in modern Korean meteorological history.