Humidity 85% when lights off any help?

Hi all

I used to grow in my garage but got fed up of mould so I gave up,
To buy weed is turning into a nightmare so i'm having another go at growing!

I have a wardrobe with a 400 HPS light and 2 silver haze from greenhouse seeds which have been vegging in the greenhouse for a couple of months. There not a great size but will do for now.

I have been taking readings of temperature and humidity before I put my girls in last night. when the light was on the humidity was 62% and temperature was 22 degrees, which i think is ok.

When the light is off the temperature is only 8.5 degrees with 85% humidity.
I had an old heat mat so I put that in and the temperature rose to 13 degrees within an hour and 15 degrees after 3 hrs, the humidity was now 87%.

so as it stands my light on temps are ok but when the light goes off the humidity is terrible.
question1: will my girls be ok?
question2: any ideas to change humidity?

What are you using for ventilation when the lights are off in the wardrobe? A constant exchange of air with fresh air coming in should help as long as the air coming in is not 85% humidity.

Hi
no ventilation at all, the garage is 8.5 degrees and same humidity as wardrobe
I have the fan running most of the time to circulate the air

Little Tommy is right, fresh air but if the room air coming in is that high you can use small dehumidifiers that come in a can or a sac, usually silica gel that absorbs moisture. Usually available at Wal-Mart and such, very cheap.