Via the FAA, here is a list of the current airport delays:
JFK, 30 minutes
LaGuardia, 37 minutes
Philadelphia, 73 minutes
Toronto, 1 hr., 36 minutes
Newark, 15 minutes
Indianapolis, 15 minutes
Note: With thunderstorms developing, there will likely be delays in Memphis after 11am.
Other airports will be affected by thunderstorms later today.
This is an image, via Twitter, of aircraft having to circle the NYC-area airports due to the fog.