Anything over 70 per cent is considered high humidity, with Londoners set to sweat in the moist conditions.
As well as making life uncomfortable, high humidity conditions have various knock-on effects on your health.
You need to drink more to replace the water you’ll be sweating out, as well as avoid strenuous activity during the hottest parts of the day.
Humidity will be at its highest at around 6am on Friday, but will remain higher than usual throughout the day, according to the forecast.
As well as affecting hydration levels, you might find that humidity affects your skin, with spots and pimples more common during periods of high humidity.
“Humidity can make breakouts more likely,” explained Dr Thuva Amuthan, founder of Dr. Derme Skin Clinics. “Warm, moist air increases sweating and oil (sebum) production, which can mix with dead skin cells to clog pores.
“Humid conditions also make it easier for acne-causing bacteria to thrive on the skin’s surface. This combination can lead to more frequent or inflamed spots, especially in areas like the forehead, back, and chest.”
If you’re breaking out more than usual, resist the urge to pop or pick your spots and pimples, as this increases the risk of scarring and long-term masks.
Instead, take Dr Thuva’s tips on how to combat pimples during humid periods.
What to do to combat pimples during humid periods
You can add some extra steps to your skincare routine to help counteract the greater risk of pimples.
Dr Thuva recommends washing your skin gently twice a day with a mild, non-comedogenic (one designed to prevent clogging of pores) cleanser.
When moisturising, be sure to use lightweight, oil-free products to similarly avoid clogging up your pores artificially.
Try to avoid heavy creams or makeup that trap sweat and oil. Many suncreams can be heavy on the skin, so if you’re spending time in the sun during the humid periods, consider switching to a chemical rather than a mineral suncream, which is lighter for your skin.
