I too live in a warm climate where the summer time tap water temp is 25-26C and even in winter it is 22C.
I found it was too much mucking about trying to cool things down so I just develop at the temp it comes out the tap.
I usually use Microdol X and Pyrocat HD and I can't say I see too much difference in my negs.
I guess I feel lucky to be in the northern US where the standard water temperature is 40-50 degrees F.
i dunno about that
when i lived in somerville
my tap water was about 74-76º in the summers.
i had a fridge i would keep a "cold" cylinder
to reduce my temps.
but then i started to use a glycin developer
and 72-75º was what it liked, so i stopped ...
I don't see any difference, except for shorter development times, when using a warmer processing temperature. It is simply easier for me to maintain a 75 deg. F (24C) year round so I've standardized on that. Kodak publishes development times at various temperatures for their products. Other manufacturers don't. Ilford publishes a cross reference time/temperature conversion chart that works well for common MQ and PQ type developers that you can find here.