If you're going to be wearing a shirt I like the vuori strato shirts, new balance tech shirts, and lululemon running shirts. Pretty much anything polyester by the big running shoe and athletic apparel companies will work though, doesn't really matter too much.
I'm of Northern European decent and I reside in Florida. I take sun protection seriously.
When I run outdoors during daytime hours I wear a long sleeve shirt with UPF 50 protection, a pair of UPF 50 open finger gloves to protect my hands, a UPF 50 wide brim hat with neck drape, and I slather sunscreen on my exposed legs and also on my face and neck just for some added protection from UVA/B indirects. I also wear UVA/B blocking sunglasses.
My preference for tops are for 100% poly shirts with a waffle weave knit. This type of shirt has the best breathability and stays the driest in moderate conditions.
When it gets too hot in late summer I switch to night or pre-dawn running so that I can wear short sleeves.
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Lulu shirts are so underrated! I've ran in 75-80 degree weather and honestly feels cooler than having the sun burn on your body! Little pricey but if you snag them on sale it's a steal. "Metal Vent Tech"
Above 60 degrees, which is 9-10 months per year in FL, I usually go shirtless.
If I feel out of shape, or I’m doing a very easy run, cotton t shirt. I really don’t like dri-fit type shirts. Especially if it’s above 75 and humid. Dri-fit does nothing in those conditions. I try to avoid running from 10am to 4pm to minimize sun exposure.
The Soar hot weather t-shirt is amazing. It's so light you can't really tell it's there. But it costs a fortune, I managed to get one half price but that's extremely rare.
Otherwise, just go for a singlet. As soon as it hits 18C, I'm all-in on the vest and 3-inch split short combo
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