Summer/hot season makes everyone agressive. I notice people drive more agressive on the streets and highway compared to cold/rainy (duh) season.
And being stuck in traffic at a temperature of 90 degrees or higher will make everyone stressful and agressive. So, that's one cons for high temperature.
And for those who plan on going to Las Vegas, try to avoid driving on daytime when the road is extremely hot, in which your tire(s) can rupture.
We don't want that.