https://www.wunderground.com/cat6/Wutip-Hits-160-mph-First-Category-5-Typhoon-Ever-Recorded-February?cm_ven=cat6-widget

We might be seeing some unsettling warmth but fancy facing down a 160 mph storm instead?

The report says the critical factor was favourbable conditions aloft, with minimal wind shear; SSTs were not exceptional. Nonetheless, an unusual event.

Maybe that stagger toward ever stronger storms in Feb , that we see reported,does have something else 'helping it along'

https://www.theguardian.com/environment/2019/mar/04/heatwaves-sweeping-oceans-like-wildfires-scientists-reveal

"The research found heatwaves are becoming more frequent, prolonged and severe, with the number of heatwave days tripling in the last couple of years studied. In the longer term, the number of heatwave days jumped by more than 50% in the 30 years to 2016, compared with the period of 1925 to 1954."

The 'Threefold increase' over recent years seems to point toward a little 'something extra' that would first see our first Cat 4 ,a couple of Feb's back, and now this first Cat5?