Every single time I try and sail for any reason, the wind is always going the wrong way so I can't get the full sail effects. Speed 1 is good to get you somewhere but it just takes so damn long dude. When I sail it's like less than 20% of the time being at speed 3 with open sails and open water. And even if it does happen to be going my way, it usually just changes to a worse direction in 5min or less. Takes me like 15min just to sail around places when I need to transport ores or what have you. It's really frustrating, in a boring way.
I would kill for an item of some kind that let you "control" the wind for a bit. Even if it took resources or special resources or something, just so I could Wind Waker style change the wind once or twice a day so I could sail somewhere without it taking an hour. I set speed to 1 and then just stop playing because I can go take a piss, make an entire pot of coffee, drink it, and piss again, before coming back and seeing I'm still only halfway there.
Source: https://www.reddit.com/r/valheim/comments/m0rfqn/is_the_wind_programmed_to_always_be_facing_the/