December 20-21 trough March 20-21 of the following year, depending on the specific years. It has the same starting and ending dates all northern hemisphere countries like the United States, England or Russia have.
Mexico is in the Northern Hemisphere so when it is winter in the U.S. it is also winter in Mexico.
Paris, of course. Mexico has a large range of temperatures, but only few places in Mexico receive winter snowfalls, as Paris usually does.
once every winter
winter, to Mexico
no
Summer: Mexico City, Mexico Winter: Grenoble, France
They go about their daily business.
mexico
it is so cold
they migrate to mexico for the winter
mexico
Winter. Yeah, Mexico is still in the Northern Hemisphere. The half of the world above the Equator. You have to go below that line before the seasons switch.