No I'm not talking about the weather but about the lighting in your darkroom. Is it safe? Is it the right colour? Is it to close to the enlarger or developing dishes? How do you find out?
There is a simple test, you will need to cut some photographic paper into about 6x6 (150 x150mm) and lay them flat in various places with the lights off around the darkroom with a small object like a coin on the top. Don't forget to mark each piece with the location you have placed it in. Switch on the safe light(s) and leave them for five minutes.
Then develop all the pieces as you would normally, if they all come out blank then there is not a problem. However if you can see the image of the object/coin on any of them you know that the light is too strong in that place and will fog any paper you leave out. You could move the light further away. Now if all the bits of paper show signs of an image it means that the safe light is the wrong colour and will need to be changed or your darkroom is not light tight.