When temperatures drop quickly I find that I need to do a few nose-only breathing workouts (low intensity, HR between 60-70% of max) in order to acclimate like this.
Nose breathing probably helps because your nose will warm up the air before it enters your lungs.
It takes some getting used to, but you probably should breath-in (nose) breath out (mouth) anyway, even in warmer weather. (Keep the CO2 on one side, and fresh O2 stream coming in with slightly better efficiency)
It takes some getting used to, but you probably should breath-in (nose) breath out (mouth) anyway, even in warmer weather. (Keep the CO2 on one side, and fresh O2 stream coming in with slightly better efficiency)