There are several factors that may lead to canker sore outbreaks during the cold months:

Dry Air and Dehydration

Cold weather often brings lower humidity, which can dry out your mouth. Dry, tissue in the mouth is more prone to irritation and injury, which can lead to canker sores.

Stress on the Immune System

Winter months can stress the immune system due to cold temperatures, less sunlight (reduced vitamin D levels), and seasonal illnesses like colds or flu. A weakened immune system may increase susceptibility to canker sores.

Dietary Changes

People may eat different foods in winter, such as hot beverages or acidic foods, which can irritate the mouth and trigger canker sores.

Viral Infections

Cold weather often coincides with an increase in viral infections like colds and flu. These can trigger immune responses that sometimes include the development of canker sores.

Stress and Fatigue

Winter can bring about seasonal stress or fatigue, which are known triggers for canker sores in susceptible individuals.