racing it is hot, but it's dry hot, so much more comfortable & from my point of view, with health problems its brilliant for any aches & pains, we've been at different times & first time we went was November, which has a cooler breeze, but still very hot, but the water in pools can be cold, though the sea is still warm - DD was only 3 at the time & she coped fine with the heat & that was even doing the Valley of The Kings, which is dessert & very hot, well over 100 degree if I remember it correctly.
From the South Sinai area you can get to lots of places, St Catherine's Monastery, Petra (Jordan) Jerusalem, Dead Sea etc & all of the Egyptian sights, though some are long days travelling & early starts but comfortable & well worth it - we did TaBa last April, which is further up the coast, but Dahab is still our favourite beach, something about the place it's like having a giant massage, you just instantly relax there - Pyramids & Sphinx are on the other side of Egypt, so a long trip, but there are lots of trips that do go there, Valley of Kings, Abu Simbal temples, Luxor etc are all nearer, so early start day trips, as is Petra etc.
If you go to Dahab, go into town & book trips with local tour companies, lots of them about & MUCH cheaper & you get exactly the same, but without the very hefty commission charged by your tour operator - TaBa sadly as this sewn up, so you have to go with your tour operator - if you go to Petra - beyond amazing, i want to go back - then go the by ferry to aquaba route - you can go via Israel, looks cheaper but we were warned by friends who were there before us that you can waste half a day getting through Israeli customs - borne out by people in our hotel who went that route too - Jordan on the other hand was a breeze & the people were so lovely & welcoming.
HTH