This is so subtle that I don't know if I'm imagining it. I think I hear two different pronunciations of this word. Are these really distinguishable? Wikipedia says /wɪ ˈskɒnsɪn/, but their audio link sounds to me like Wis-consin. Wiktionary lists the two as separate pronunciations.
I think I say Wis-consin, but for example newscaster Robert Costa seems to say Wi-sconsin. I wonder if this is a regionalism or a difference between how locals say it and how other people say it. But my wife and I both seem to say Wis-consin, although I'm from California and she's from Buffalo.
I had always imagined that things like this were merely arbitrary rules used for hyphenation. In English, there are no smaller morphemes contained within the word, and the Algonquian etymology seems to be unknown. It came to English through French, which does have words like Scaramouche with word-initial "sc." If there is a difference that I'm hearing, is it a difference in the length of the first syllable, or a difference in how the "s" and "c" are articulated together?