When it is raining you can check your ceilings. Do you have soft spots, damp spots or worse yet drips?

Check your windows. Is any water coming in or is there just condensation?

Look under the sinks and in the basement or crawl space. Is any of the plumbing dripping or is there water seeping through the walls?

Mark these locations with a pencil (not pen or marker)to help you remember where they are. As soon as the weather is dry, the leaks can be repaired. Primer will cover the pencil marks.
Not fixing the leaks can lead to mold growing or wood becoming damaged.