Hi - I'm new to the forum and have visited the States a couple of times over the last 15 years (I'm from the UK). The most recent trips were to Florida but a group of us are thinking of spending 3 or 4 weeks on the West Coast next year. Part of the trip would be hiring an RV for 7-10 days and starting in Las Vegas we'd be visiting Grand Canyon, Monument Valley, Zion National Park, Bruce Canyon and Capitol Reef. I've not finalised details yet but we would have to come during July/August (school holidays) - would the temperatures in California/Utah/Neveda be far too hot to travel comfortably at that time of year - especially in an RV?