Field Notes · 23 August 2026 · ledger

Measured: heat-stress days in Obihiro, summer 2026

This week: how many days this summer did Obihiro, Hokkaido reach each WBGT heat-stress level. The result: 0 days at danger, 9 days severe, 29 days warning, 45 days caution, out of 54 days observed. The summer's highest reading was 30.2 on 16 July.

How I measured it

KUON GEO stores the Ministry of the Environment's WBGT readings for every point in Japan, every three hours in season, and keeps them. Once a day a normalisation job takes each point's daily maximum and its level. This note reads that layer for the Obihiro point (station 20432, 1.3 km from the city hall), from 1 July 2026, the first day in the archive, to 23 August.

The levels are the Ministry's own: caution from 21, warning from 25, severe warning from 28, danger from 31. A day counts for a level when its daily maximum reached that value.

One thing to keep in mind

This is one point, Obihiro, and the archive starts on 1 July 2026. It is not a climatology and it says nothing about other years. The numbers will change as the season runs; the page /here shows the same count for any place in Japan, updated daily.