I had a ride today that started out with very light W winds but the wind came up over the afternoon and I ended the ride with 18 miles into a 15 mph N headwind. I got home and uploaded the ride to Strava. The overall results were disappointing. I knew that my overall speed suffered during the last leg but my estimated wattage was way down as well. I created a couple of segments and the first two-thirds of the ride were as expected. The wind picked up during the last third of the ride and as mentioned was head-on for the last quarter. I knew what my speed over that segment was going to be but the wattage was also way down even though this was the most difficult segment of the ride. Is there any way to input wind speed and direction to get more accurate power estimates from Strava?

I've run into this before when I've had to shift down and power into the wind like a steep grade, but the wattage reads as if I was out for a leisurely cruise on a calm day.

No, there's nothing you can do about changing Strava's algorithm for wattage estimates. What you can do is give Strava better data, e.g. by using a heart rate monitor, or better yet, by using a power meter. Or get both with Cycleops' Powercal strap. I don't know for a fact, but I suspect that Powercal, while it estimates power too, is more accurate than the Strava.

I couldn't help but smile when I read the OP. ( Does no one ride for sheer enjoyment anymore? )...I would think there would be a way but it would involve mounting a wind speed sensor on your bike that had a way to link up with your smart phone app. Then the program you're running would have to be set-up to make the proper calculations. Strava probably doesn't currently do this.

Now if Jim Lovell ( Apollo 13 ) happens to be your next door neighbor, maybe he might be able to help you do the calculations necessary to account for high winds. Otherwise, you could just delete the ride which might be the easier way to go.

You could just copy the Strava graph into a photo editing program and then modify the power axis to show whatever power you think you were producing. If this sounds ridiculous, it's only because you're giving the Strava calculation far more credibility than it deserves.

If you want power data, get a power meter.

or just buy an iBike Newton, which measures wind resistance.