Uff da! (sometimes also spelled huffda, uff-da, uffda, uff-dah, oofda, ufda, ufdah, oofta, offtah, or uf daa) is an exclamation or interjection expressing bafflement, surprise, or dismay. Of Norwegian origin, the phrase was brought by Scandinavian Americans in the Upper Midwest, New England, and Pacific Northwest regions of the United States during the 19th century. The Swedish exclamation ojdå is similar in meaning and usage.  
In Norwegian, uff or huff is an interjection used when something is unpleasant, uncomfortable, hurtful, annoying, sad, or irritating. Uff da is most often used as a response when hearing something lamentable (but not too serious), and could often be translated as "Oh, I'm sorry to hear that".
North American usage
Uff da can be used as an expression of surprise, astonishment, exhaustion, relief and sometimes dismay. Within Scandinavian-American culture, Uff da frequently translates to: "I am overwhelmed", somewhat similar to the Yiddish phrase oy vey. Uff da can often be used as an alternative for many common obscenities. 
The phrase has become a marker of Scandinavian heritage. The term is predominantly prevalent in the upper northwest regions of the United States. Uff-Da Airport is located in Stoughton, Wisconsin.  Various communities have incorporated the term into local festivals. The community of Spring Grove, Minnesota holds an annual Uffda Fest!. The town of Ostrander, Minnesota holds an annual Uff Da Days event. The city of Rutland, North Dakota holds an annual Uffda Day Fall Festival.
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