I was a sailor for about 30 years before i took up kayaking and regularly checked wind speed. Other than that, i have ridden and still do ride motorcycles for more than 58 years. I know what 40 mph winds feel like. When the waves are 8 feet high (bottom of trough to wave top) and the tops are blowing off them, you have to have a death grip on your paddle to keep it from being blown away and forget trying to keep a hat on--that's a lot of wind. When limbs are being blown out of trees on shore and all the fishermen have hung it up--that's a lot of wind. By the way, I don't mean that all the waves were that size, because under those conditions, waves are very irregular--except in tidal race patches. Those can get downright spooky.
I didn't have an anemometer with me and wouldn't have been able to use it if I had; I was kind of busy. I would venture that in these conditions the waves actually offer some shielding of the wind for kayakers. That might sound kind of nuts, but think about it; when you're down in the trough the wind can't be the same as it is at the crest. In a strange way, the waves actually help to propel a kayak into the wind, because of the upward current on the face of the waves.
Yesterday, I was going downwind in some pretty good sized waves, which were great for surfing and the wind was probably less than 15 mph. The waves were very much enhanced by the opposing current and a bunch of ships tug boats and especially by very large high speed motor yachts. What does that have to do with anything? I don't know, but it was fun and that's really why we're out there.