Unfortunately, yes, as it seems as if cold sore outbreaks are linked to temperature changes. It is possible that an increase in cold sore outbreaks occurs because the colder weather tends to re-activate a virus linked to cold sores, the HSV-1 virus. When you are exposed to the colder weather outdoors and then enter a nice warm home, it can be enough to trigger an outbreak.
There are several reasons why cold sores can be more prevalent in the winter, as the harsh sun and wind can dry out your lips, creating more hospitable conditions for the virus responsible for cold sores. The dry, warm air indoors can encourage the virus to spread and may lead to more frequent outbreaks. Additionally, you might receive less vitamin D during the winter, and which can also increase the risk.
Even something as simple as planning a holiday can make it more likely you will develop cold sores because of elevated stress levels. Seasonal ailments like colds and flu can leave you more vulnerable to an attack as your body will already be busy fighting other viruses.
If cold sores are a problem, make sure your diet is rich in vitamin C, E and l-lysine. Try to keep your stress levels to a minimum and make sure your lips are well moisturised.