Meteorologists (weather forecasters). It's defined by the calendar months of December, January and February. Turn the page into March 1 and we're in meteorological spring.
Astronomical Winter is defined by the solstices. The spring solstice starts this year on March 20th 2023
We had a fine discussion about this last winter. The southern states would probably go by meteorological spring and the northern states (with a later spring) would probably go by astronomical spring. Last year, spring bloomed in my part of Massachusetts in very early March 2022.