Travel issues continued to snowball at Denver International Airport on Monday after over 600 flights were canceled or delayed because icy conditions and poor visibility plagued the runway, according to reports.

The Denver Post reported roughly 650 flights were affected, which could not have come at a worse time.

In fact, Denver International Airport was on its way to recovery after a tumultuous week of holiday travel, when Southwest Airlines stranded thousands of passengers in airports across the country, including Denver.

Snow showers were expected to continue through most of the day and into the evening on Monday, Fox station KDVR in Denver reported.

At 7:30 p.m. EST on Monday, Denver International reported 139 flights canceled and 418 delayed.

Across the country, there were 7,077 flight delays within, into, or out of the U.S., according to flight tracking website FlightAware.com, and 710 cancelations.

Denver’s airport also led the nation in cancelations and delays during the day, according to FlightAware’s data.

Southwest Airline is a major carrier that flies in and out of Denver.

Two days before Christmas, a winter storm that swept across the country crippled air travel, leaving many passengers stranded in airports across the country.

Delays continued through the weekend and into the following week.

The major disruption caught the attention of the US Department of Transportation and the Biden administration on Tuesday, both stating airlines will be held accountable if customer service plans aren’t followed during the cancelations and delays.

As of Thursday morning, Southwest accounted for 58 % of canceled flights in the world with 2,356 cancelations.