I live a hot weather country 26c to 35c.
Is it good to use 5w30 oil for 2016 Lexus is200t f sport ??

The owner manual and oil cover said to use 0w20

5w30 vs 0w20

Which one is better at running in hot weather country ?

 

just use 0w20

 

Depends on how much you want to pay, Amsoil makes 0w30 and 0w40 motor oil.

 

This thread could go on for days with discussion about what oil to use.
In other parts of the world (where it's hotter) the 3IS recommended oil is actually 5W30.

W30 is good for about +35C...which by the OP's confirmation is at the top of his temp range.
For some margin of error, a 0W40 or 5W40 would be better suited...in case the ambient temp does climb a little past the max range.
I'm not suggesting you switch oil viscosity, just putting the info out there.
Since it doesn't seem to get cold where you are, the 0W and 5W aren't really that critical.

 

5w30 for your hotter weather.. that's what the dealers use in such climate.