A total of 99 flights were affected in some way Monday morning when thick mist enveloped the Guadalajara International Airport from around 6 a.m.
Air traffic controllers reprogrammed or redirected 32 flights, most of them to Puerto Vallarta. Another 67 flights were unable to leave on time due to the foggy conditions.
Normal operations resumed around 10 a.m. once the mist had lifted.
Fog is not an unusual occurrence in the area to the south of Guadalajara in the early morning winter months. The mist often mixes with contaminants that become trapped in thermal inversions, which occur when cool surface air is overlain by warmer air.
Fliers should be aware that early morning delays at the Guadalajara airport are a real possibility in December and January.
Meanwhile, Puerto Vallarta is bracing for a massive influx of tourists over the coming week. Tourism authorities report that hotel occupancy will be approaching 100 percent. Around a half a million visitors are expected in the port between Christmas and the New Year, according to Tourism Secretary Enrique Ramos.