I sweat the most in the winter, and in the summer commutes home.

In the winter, it's because I don't have a wind-proof shell that breathes worth a damn. Doesn't matter what I wear under it, or if it's 40 or 30 or 20 out.

In the summer, it's the 10 miles in 102 degree temps and sunshine that do it.

I don't care though, my commute IS my workout, and I have showers at both ends of the ride.

I sweat A LOT. I'm of Eastern European descent (pale white skin, grew up in cool, dry climate) so hot, humid summers in NY don't make it easier. I have little problem with sweating though. I follow some elaborate procedures to stay dry, fresh and clean at work and that works. Other than that, I don't care. I 'd change clothes and shower a few times a day if it gets really bad. As long as I don't stink offensively I can sweat a river so I follow my anti-stink procedures and I keep sweating

Try avoiding caffeine, alcohol, carbonated drinks (soda) and spicy food on hot days, they'd make some people sweat and/or stink more.

I don't sweat too much DURING the bike ride, but I start pouring out rivers of sweat just AFTER I stop. Takes about a half hour or so of cooldown time for the sweating to taper off, so I usually wait at least 15 minutes before I shower - otherwise I'm still sweating in my clean clothes after the shower.

I sweat like a pig no matter the temperature, even when I lived up north I would ski in a light sweatshirt because anything that broke the wind turned me into an oven. However, I ride my 9m commute with ~20lbs of extra weight at around 16-20 mph, so it doesn't exactly help the situation.

Luckily, there's a gym on campus that has showers that I use, so sweat isn't too much of an issue after the ride.

Commute... plenty... it is very hilly, so I am up and down and up and down, and I tend to sweat from my head a lot.

Obviously it is the same for workouts... Only I also tend to use part of my water bottle contents to wash off my face from time to time so the sweat doesn't blind me... but it makes me look really wet.

Errands... hey I take it easy on those... just cruise along and I tend to avoid hilly routes when running errands... I will go longer distances to "go around" when and where I can. So I tend to look fresher when I run errands or make a pub run. I figure I have to deal with clerks and help in stores... so best to not look like a sweaty mess during those times.