A tea kettle with boiling water inside
The Difference Between Boiling Water And Microwaving It
Microwaving hot water is much easier and quicker than using a stovetop kettle, but if you're expecting the same results, you may be disappointed.
According to a 2020 study by AIP Advances, liquids warmed in the microwave will end up hotter on the top than on the bottom. Research showed a difference of 14.04 degrees F.
With boiling water, the water is warmed from the bottom, which causes it to naturally rise and increase the temperature of the surface liquid much more evenly.