With summer on its way, I'm looking for kit that I can wear in the summer to keep myself cool. My typical routes don't have a lot of shade. What should I be looking for? I know I am going to want a full-length zip, but what else?
Short cycling jerseys are normally designed to be ridden in summer. Unless the conditions are really extreme (e.g., North Africa in summer), one should be fine with short jerseys and shorts and sunscreen.
Use modern synthetic materials that basically all manufacturers use now, they are made to enable evaporation of sweat. Look at what people who are paid to ride their bikes wear. They only put on long sleeves when it is colder or when using skin-suites for time trials. But they do not ride in extreme conditions in summer (southern France or Spain in summer is not extreme yet).
What they do in very hot stages is to pour water on their bodies or even to put packs of ice into their jerseys. Unfortunately, water is a sparse and heavy resource so we usually cannot waste it, but if you are at a water source, do get a wash, do wet your headscarf or a cycling cap in water, and so on. The evaporating water will cool you as nothing else could.
This is a matter of personal preference. I live in a hot climate. I've worn everything from sleeveless jerseys with perforated backs to long-sleeved jerseys in hot weather. My current preference is for long-sleeved jerseys, in order to get the added sun protection. There aren't a lot of lightweight long-sleeved jerseys, but there are some, and some advertise their SPF ratings.
Some clothing manufacturers advertise "coldblack" jerseys (black, but intended for hot weather). I've never tried one, and I'll admit I'm skeptical they'd be comfortable. I always wear lighter colors.
Jerseys are designed to wick sweat and breathe well. Modern performance textiles are pretty amazing.
Over the past 4-5 seasons I've had great success with UV-blocking, but very thin, arm- and leg-covers. Most of the major brands (e.g. Pearl Izumi, Castelli, Sugoi) have them now, and you can find non-brand ones online with all kinds of designs if that's what you're into.
The ones that are purely sun-protective, as opposed to warming, are actually very good at cooling; unless my arms are shaved, they're cooler with the sleeves on than not. I couldn't make the (possibly psychological) jump to wearing black ones, so mine are white, but I'm not sure I'd unreservedly recommend them. They do get dirty and the fine weave of the cloth tends to hold onto stains. (One person I cycle with has yellow ones and I've also seen blue; neither looked as dirty as mine look straight out of the wash.)
They're not cheap, but based on my math they're not more expensive than the avoided cost of multiple tubes of decent-quality SPF 50+ sunscreen over a couple of seasons. Plus you just peel them off at the end of a long ride and throw them in the wash, and you don't have to spend 10 minutes in the shower scrubbing off layers of sunscreen and road grime.
Avoid jerseys with mesh backs; they may be cooler, but it's a pain to keep a good application of sunscreen underneath them, and even more of a pain to get a pointillist sunburn.
I loved this durable cycling jersey. I rode my bike in hot weather. It was comfortable for me, of course, there is sweat, but the body is pleasant.
Material: Polyester. The fabric is lightweight and breathable. This T-shirt is made of synthetic fabric for effective moisture removal and air circulation. I have never experienced overheating while riding. This is very important for hot weather. In addition, a small price was important to me.
