Overview
- An online, anonymous questionnaire on the JMA website runs through March 29 to gather preferences on the shortlist.
- Survey results will be combined with expert input to select the official term by the end of May for use in forecasts this summer.
- Candidates include 「超猛暑日」, 「炎暑日」, 「酷暑日」—a label coined by the Japan Weather Association in 2022—along with 「大暑日」 and 「烈暑日」, and respondents can also propose other names.
- Japan’s forecast terminology set in 2007 defines 「夏日」 (25°C+), 「真夏日」 (30°C+), 「猛暑日」 (35°C+), and 「真冬日」 (below 0°C).
- JMA notes 40°C-plus days have occurred annually since 2018, and Japan’s record high of 41.8°C was observed in Isesaki, Gunma, on August 5, 2025.