Why Is My Period Irregular In Summer? A Doctor Explains Seasonal Cycle Changes

As someone with endometriosis, fibroids and adenomyosis, I have a LOT of beef with my menstrual cycle. I don’t ever have a calm period and I usually am confined to the sofa until it’s over with. It’s grim.

This summer, however, it has been WILD. The one thing I can always rely on is my period being on around the same day every single month. It’s a small win but a significant one in terms of understanding where I am in my cycle, what to expect and when it’s safe to make plans. Until these past couple of months when that has gone OUT the window.

My periods this summer have been late. My last period was very, very light to the point that I wondered if it was implantation bleeding and I was actually pregnant. This month? It’s diabolical. I am getting through sanitary towels faster than I thought possible and my cramps are unbelievable. Energy levels? Depleted. RIP to feeling awake.

I wondered if this could have anything to do with the heatwaves we’ve been experiencing and while there is limited research on this matter, Dr Suzanne Wylie, GP and medical adviser for IQdoctor did have some insights for me.

Dr Wylie says: “When it comes to heatwaves and periods, the research is still relatively limited, but that doesn’t mean women’s experiences should be dismissed. We know that the reproductive hormone system is closely linked to the rest of the body, so anything that places additional stress on it, including prolonged periods of very hot weather, has the potential to influence the timing of ovulation and, in turn, the menstrual cycle.

“During a heatwave, people may become dehydrated, sleep less well, feel physically exhausted or experience higher levels of physiological stress, all of which could contribute to temporary changes in hormone regulation in some individuals. That means some women may notice their period arriving earlier than expected, later than usual, experiencing a lighter or heavier bleed, or even spotting between periods.”

She advised that while we don’t have strong evidence showing that heatwaves directly cause widespread menstrual disruption, “it is certainly plausible that extreme heat may affect some women more than others, particularly when combined with other factors such as stress, travel or illness, and this is an area where more research would undoubtedly be helpful.”

Honestly, this makes a lot of sense. I am definitely struggling with the temperatures this summer and have been well out of my usual routine as I am throwing myself into summer socialising. My body is likely completely out of whack and I’m not surprised on reflection that my periods have been impacted by this.

Dr Wylie urges, though, that if you’re concerned about your periods, you should speak to your GP, saying: “I would also advise seeking medical advice if several periods have been missed without an obvious explanation, if menstrual cycles suddenly become much more irregular than usual, if bleeding is unusually heavy, persistent or occurring between periods, or if there is a positive pregnancy test accompanied by pain or bleeding, as these are situations where we would want to investigate further to rule out any underlying medical concerns.”