I know it is not possible to get a perfect 90-deg but that sun on a bright clear Alaska day can be brighter than some people expect
I agree completely, I live pretty damn close to the tropic of Cancer and we have all sorts of problems with clarity of air. Humidity and dust cause a constant haze. I've found places with clearer air mean much greater risk of sun burn even if they are a long way from the tropics.
Your air should be pretty free of dust and humidity so air quality should be verging on excellent most of the time.
In 2009 I went to Lake Tittikaka and was staggered by the quality of the air. Its the first time I've ever noticed the air 'sparkle'. High altitude thin air, lack of pollution and very low humidity cause this I think. My group got really badly sunburnt that morning, it caught everyone out.
I know dubaiphil and myself are very jealous of your clear bright days, we get hot hazy and sweaty atm