In your area your not gonna see much of a difference in oil flow with 5w30 vs. 10w30. If it were my car i would use 10w30 year round. 5w30 has the advantage in flow when temperature drops to below 10F.
Is it a dino or synthetic oil depends the 5w-30 synthetic does well in higher temperature...if using dino in your area either weight would do fine. If you strain the oil a bit go with the 10w-30 as it is perfered in warmer weather.
I think you should stay with the 10/30 in a hot climate. My truck has never seen 5/30 till now during the cleaning faze of ARX.Driving back from Miami (about 76 miles) my temp.gague was past the middle till I got off the XWAY.I am now in the rince cycle with Chevron Supream 10/30 and plan on driving the highway soon.We'll See!
Another vote for the M1 10W-30, but it isn't major and depends on how/where you drive.
I checked the oil temp in my '04 Camry 4 cyl after driving 80 MPH on hwy 40, AC on, 107 degree ambient. The last 10 miles of driving did not have any hard or sustained grades. I shot IR thermometer on oil filter and oil pan. My oil temp readings were between 225 and 229 degrees. The front of the cylinder head was at 188 degrees and the coolant discharge from the engine was at 200 degrees. The engine was idling when these temps were taken.