Where I live, its 99% outside most days, some days its 99% humidity
for 24 hours a day.
That doesn't mean its raining!
It can be sunny not raining and still 99%.
Indoors it varies from 23 to 75%.
Humidity indoors, is the result of our breathing and sweating,, we
give out one and a half litres of water vapour every 24 hours and 350
ml of that is when we are regulating our temperature while in bed
Excess water vapour leads to mould on the walls, damp cold beds and in
the long term ill health, spores emitted by the mould get into our
chest and make us ill.
We put this water vapour in the air by breathing, sweating, drying
clothes indoors, not running the ventilator while cooking and washing,
not closing the kitchen and bathroom doors.
The simple solution is to open the windows for five minutes in the
morning and evening.
If you don't want to let the place get cold by opening the windows,
then buy a de-humidifier and keep it running 24 hours a day, after
about two or three weeks the problem should be solved.
Just make sure that the de-humidifier can deal with the amount of
water vapour you your family and animals are adding to the home every
A small active child or dog will add more water vapour to your home
per 24 hours than you do.