OISST warm-event overlap with 127 buoys rose from 1993-2006 to 2007-2019 under equal warm-day frequency

At 127 moored stations, mean event-day overlap between OISST v2.1 and buoy warm events rose from 0.496 in 1993-2006 to 0.604 in 2007-2019. The change was +0.108 (95 percent spatial-group interval +0.066 to +0.152). The OISST-minus-buoy duration change was -0.22 days (-2.07 to +1.76). Both networks showed better overlap. We compared warm events in daily OISST v2.1 and moored buoy records across input eras. We removed separate seasonal cycles and linear trends and gave each record the same warm-day fraction in each era. We measured event-day overlap, duration differences, and event joins on paired valid days. With a less strict coverage rule, 68 stations show no clear recent change of event-day overlap or event joining between 2016-2019 and 2022-2025. The results show that changes of variance and duration do not by themselves establish a loss of event agreement. The bundle gives paired-era estimates, spatial-group intervals, threshold and gap checks, code, and exact input hashes. Buoys are assimilated by OISST. The sample is regional, and the recent eras are short. These are warm-event diagnostics, not corrected global marine heatwave trends.