humid weather in the rainy season provides fertile environment for various fungal & bacterial infections of skin. It can be avoided by
Ultraviolet rays can pierce clouds as well; so use of sunscreen is must. Use a water resistant lotion as it can give better protection in case you get wet.
Proper use of moisturizers is must during monsoons as weather can adversely affect your skin. Use an oil based moisturizer if you have a dry skin & water based ones if you have already oily skin. Also oily moisturizers will serve better if you tend to get wet often.
Preferably use a mild, non-soapy cleanser that ensures deep cleansing to wash away impurities from your skin.