When do most Southwest snowbirds leave?

We leave Arizona about the end of April. Around the 1st of May it starts getting nice and warm in central WA. I do notice that a lot of RV's hit the road about the 1st of April.

If you snowbird in NM you must like cold weather as it is not an ideal snowbirding location no matter how far south you are. In AZ most snowbirds stay through March and those that love major league baseball get to enjoy Cactus League action during that period.

We are full-time residents of AZ and live in a stick & mortar community where nearly 1/2 of the homes are Snowbirders. Most leave in April with all Snowbirds gone by May claiming 80 degrees is too hot. Us desert rats can't wait for the heat of May so we can enjoy our pools. The winds generally start and are strongest in April. Again we don't find the winds annoying, all tho we did have to chase a large patio umbrella down that landed over a mile away & a large C span type dish nearly a 1/4 mile (my fault, had taken it loose from the base to junk out). Both of these were caught up in what we call dust devils (baby tornadoes).

rocmoc n AZ/Mexico

When the snow is gone back home. Usually April 1st .... but not last year. This year we're gonna try April 15th.

March is to soon. The weather in Washington state is still wet in March and still nice in Yuma. End of May works for us. Getting hot in Yuma and drying out in Washington. Never had any serious wind issues.