You did great FM! With a temperature of 84F and dew point around 60F, on the pace calculators that is going to effect your pace by roughly 5%. So a 1:30:00 half in ideal weather would be modified by around 4-5 minutes with this heat. Add to it that you haven't really been running in heat like this means you are not acclimated to it, taking it cautiously was absolutely the right idea there.
Even taking it cautiously, you pretty much nailed your goal time once it is heat+dew point adjusted, so I think all of your hard work paid off for this race. Unfortunately we all are at the mercy of the weather, so here is to hoping your next race is in more ideal temperature
