Water boiled in a microwave is generally not at an even temperature
But microwaves don’t heat water evenly, so the boiling process is
difficult to control. Microwave ovens shoot tiny waves into the liquid
at random locations, causing the water molecules at those points to
vibrate rapidly. If the water isn’t heated for long enough, the result
is isolated pockets of very hot or boiling water amid a larger body of
water that’s cooler. Such water may misleadingly exhibit signs of
boiling despite not being a uniform 212 degrees.
