Retroid

Entirely subjective, but I often think of certain games as "summer games" because I played them in the summer as a kid. Tony Hawk games are absolutely on that list, as are Dave Mirra's BMX, Tomba! 2, Crash Bandicoot, the Sonic games, Vectorman, Mortal Kombat, Pokémon Stadium, Bomberman, etc.

Some games that actually have a summery vibe would be Cool Spot, Donkey Kong Country (1 and 2 mostly, and parts of 3), Zombies Ate My Neighbors, Aladdin, The Lion King, Pitfall, Shantae, Banjo-Kazooie has some summery areas, maybe Yoshi's Story?

I'm hoping to play some Tony, but they don't run so well for the GC and PS2.

Thinking about revisiting Super Mario world too.

I like to do RPGs during summer when I can play somewhat consistently. Considering starting Chrono Trigger. Or maybe just completing some of the games I've started (like Paper Mario 64). Of course THPS2 is a classic, but that's something I'll otherwise play during my commute to work.

Definitely Cool Spot (I hear the Genesis version plays better but SNES version has richer graphics)

Also water sports games so WaveRace 64, Hydro Thunder, Riptide GP/2/Renegade.

I guess beach buggy racing also has a summer vibe.

Also Dead or Alive Paradise I guess if you’re into that sort of thing lol

Oh also Super Mario Sunshine? Also Outrun Coast 2 Coast