This means double and triple check your flight status if you are heading that way!
RELATED: Polar vortex brings subzero temps to Midwest
For example, at San Francisco International Airport, there about 30 flights to and fro Chicago everyday.
On Wednesday about one-third of those flights were either cancelled or delayed.
Lori O'connor and her husband landed at SFO and tell ABC7 they're among the lucky ones who left Chicago just in time. The O'Connors are in town celebrating their 25th wedding anniversary in Napa Valley.
POLAR VORTEX 2019: Here's how planes get de-iced
"We got very lucky to get out of there. Unfortunately, there are a lot of people who are still there," Lori said.
Airports spokesperson Doug Yakel says the situation could actually be much worse.
"This is a very light volume time of the year for us at the airport, so if airlines can combine flights with the next flight, that reduces the delay effect overall. So, that's what we are seeing in Chicago right now" he said.
Yakel says they are already expecting delays for later tonight due our own storm coming through the Bay Area, which could impact flights up and down the west coast.
Check out more weather-related stories, video, and images.