There was an Ask Tom in the weather section of our newspaper today that intrigued me. The person asked for the etymology of "feeling under the weather." Tom Skilling had several theories:
1) Weather plays a role in moods, such as "sunny" day or disposition or "gloomy" day or disposition.
2) Nagging ailments, such as migraines and rheumatism (not a real diagnosis, but oh well) are related to the weather.
3) People become seasick when it's stormy and head below the deck.
4) Related to a nautical phrase "under the weather bow," which refers to the windward side of the ship that catches the brunt of the wind and high seas during a storm.

I was leery of all of them, and so I checked Quinion. Nothing. Then I put it in Google (which makes me leery, too), and found:

1) This site, which also has its theories. One reference there says it was first recorded in "Reveries of a Bachelor" in 1850, while another says it was first recorded in the Austin Papers in 1827.

2) This site says it is a nautical term that originated with the British Navy. When a sailor was ill, it said, he was kept below the decks and thus under the weather.

Does anyone have a better idea of the origin of this phrase?

According to the OED, it's a US phrase that first appeared in the Austin Papers.

I didn't even think to check the OED. I guess that's the answer then, as I always consider the OED the gold standard.

But it doesn't really explain the origin of the phrase, other than to rule out the British Navy theory.