Does Weather Affect Your menstrual cycle? 

If you’re not having your period every 28 days, don’t panic. A lot of things can mess with your menstrual cycle. And, if you’ve ever wondered if weather affects your period, the answer is yes, though not in the way that you might think. From stress to travel to synching up with your besties to the changing of seasons, a lot of factors can determine when you start your period.

While the weather itself might alter your menstrual cycle if you live in a climate with drastic seasonal changes, lifestyle changes during different seasons of the year are most likely the primary factor in determining when you get your period, and how it affects you. If your periods are worse in the winter, there’s actually a reason for that.

“When it’s nice out, we also tend to spend more time outdoors and more time moving,” Dr A. Nicky Hjort told Verily magazine. “Women who exercise regularly, and who have a higher level of fitness, are less likely to suffer from a severe form of PMS, aka premenstrual dysphoric disorder (PMDD), and are less likely to have heavy and irregular menstrual bleeding.”

Basically, if you instinctively hibernate during the winter months, being less active can lead to more cramps and PMS or PMDD symptoms. Additionally, climate change also reportedly affects your period, which — coupled with time zone changes messing with your body’s internal clock — is also why your period can become irregular when you travel.

“Climate changes have effects on woman’s menstrual cycles by varying the bodies’ metabolic rate which clues [in] to hormonal inequity,” the website Wear and Cheer explained. “When anybody geographically transfers to a place where the weather is hot or cold the body doesn’t regulate automatically.”

What’s more, seasonal activities can influence your overall vaginal health. You might find that you’re more likely to get a yeast infection in the summer, which can lead to irregular periods. While it may seem like the weather is to blame, it really has more to do with what you’re doing versus weather patterns.

“Weather changes can lead to frequent yeast vaginitis and bacterial infections,” Dr John Fejes told Verily. Though it’s not the hot weather itself that makes you yeasty, but rather increased activity in hot and humid environments that create an attractive place for yeast to thrive.

Stress can also affect your menstrual cycle, and may even cause you to skip a period. Typically, people are more stressed during times of extreme activity like the holidays, which coincides with the beginning of winter. So, while it might feel like the onset of winter is wreaking havoc on your lady parts, it’s more likely the stress that comes with that time of year that’s really to blame.

“Because it affects hormone balance and many other processes in the body, psychological stress can also interfere with the menstrual cycle,” Medicine.Net reported. “In fact, stress is considered to be a common cause of missed or late menstrual periods.”

The bottom line is that weather does influence your menstrual cycle, but it’s often a secondary factor to other things like stress, travel, and changes in diet, exercise, and sleep patterns that often coincide with changes in the seasons. You likely experience varying levels of stress and engage in different levels of activity throughout the year, especially if you live somewhere that has four distinct seasons.

People living in more stable climates are less likely to experience seasonal menstrual-cycle irregularities. On the flip side, living in a climate with drastic changes, like extended sunlight, or short dark days, can determine the length of your period.