Trading at some Chicago-based markets will be closed tomorrow as Hurricane Sandy hits the East Coast, according to statements from the CME Group and the CBOE.

Equity index futures and options on futures markets will close tomorrow morning “in coordination with the announced closure of U.S. equity markets,” the statement read. CME’s New York City trading floor, which is located inside of a mandatory evacuation zone, will also be closed.

All other CME futures and options will remain open, the statement read.

CBOE Holdings, Inc. also announced in a statement “trading on Chicago Board Options Exchange (CBOE), CBOE Futures Exchange (CFE), C2 Options Exchange (C2) and CBOE Stock Exchange (CBSX) will remain closed” tomorrow.

“Chicago’s linked to New York, New York’s linked to the rest of the world. And, unfortunately, this seems to be one of the worst weather-related incidents we’ve seen in some time,” said David Stowell, Professor of Finance at Northwestern University.

Stowell, however, called the closures “an incovenience, but it probably doesn’t create irreparable harm.”

A CME spokesperson said trading on U.S. equity futures and equity options on futures had closed early Monday. Trading at the CBOE also came to a halt Monday, a spokeswoman for that group said.

A CME spokesperson said the last time stock trading was closed unexpectedly was after the September 11, 2001 terrorists attacks.