Fig 2. A time series of thermal stress in the Pacific Ocean from 1982 to 2020 at Palau, Yap, Pohnpei, Kosrae, Majuro, and Kiritimati, expressed as degree heating weeks (DHWs), which is the cumulative measure of the intensity and duration of heat stress that exceeds the average summertime maximum temperature (i.e., local climatology) by 1°C, culminated over 12 weeks and expressed in the unit °C-weeks.

The timing of El Niño events are indicated with vertical dashed lines and the thickness of the lines are in proportion to the intensity of the event.