I hate the wind. Just completed my daily ride with a 2 mph lower average speed than I have been due to the wind.

This motivated me to do a bit of reading. I always knew that in an out and back course any wind, no matter the direction, would lead to increased completion time, but never really put too much thought in to it. On a very basic level, one would intuitively think that the tailwind would make up for the headwind, but this is not true.

Here are some nice graphs. I particularly like the last one. A 25 mph wind at 0 degrees to the course increases completion time by ~22 minutes on a 25 mile out and back course.

Sure, everyone knows that wind is bad unless you are going one way with a tailwind, but this helps understand just how bad it is.