NOAA's latest U.S. temperature dataset reveals that over last 20 years (including 1996), May temperatures have been on a cooling trend: a -0.8°F/century trend.
In addition, the same dataset for 12-month periods ending May shows a cooling trend over 19 years. That trend is a -0.4°F/century.
Regardless if one refers to these climate temperature dynamics as a 'pause,' a 'stall,' a 'hiatus,' or a 'plateau,' it was not expected - no alarmist hypothesis or theory-based scenario predicted this outcome.
Note: Temperature trends are for the continental U.S. The official climate agency source of trends and chart.