In Australia, I often joke that we have Two Seasons. Given Spring just started, and we're seeing highs of 30C during the day, I continue to feel validated at this assessment. We have Winter and Summer, which Aboriginal Australians break up variably into between four to six different seasons based on common weather events like storms/rains/blooms and fauna habits and such.
When the Banbai people (towards the east coast Aus) refer to almost any season outside of July as 'Burning Time' or 'Wildfire Time', or how Kaurna people (south central coast Aus) have 'Hot', 'Windy', Wet', and 'Warm', it's pretty much always been this way, Down Under.
Beach, just like Halloween, and Christmas, and New Year's, and all other Hot Events, occur in Summer here, when it is Hot Times.
Hot Times mean Beach. Beach is more Cold And Bracing during Early Summer (Spring) or Late Summer (Early Autumn), but the Hottest Times are when the Beach is the most Beach.
The peak of Summer is Beach Time here, which is December/Jan/Feb. Where flinging ourselves into the salty undulating mass of darkness and unknowable horror that is the ocean is safer than staying on the sand, despite what waits beneath.
There's no 'globally' for it though, because of the hemispheres.
December is clearly CRISMUS up top, it's all jangly and wintry and there's often white shit everywhere. It feels horrifically off-kilter and wrong to think of July as Beach Month, but it sure as heck is for other population bodies. But then it might be different again depending on distance from the Equator, where it all evens out into Warm Soup for most of the year.