The answer to your original question is, yes it will.
It should not be the sole diagnostic test to be performed however. You must focus on moisture measurement that will identify its source, cause and location.
In the winter water becomes a solid and site drainage issues may not be evident. This doesn’t mean that you should put off your investigation for a particular season however.
This type of testing seldom is taken care of in one visit. Things that we don’t expect to happen happen in conditions we expect to be good turn out to be bad.
I was working for a forensic engineering company concerning water leakage into a public building. I performed an initial site assessment and took thermal imaging scans in the process just to see what was going on under those particular conditions.
I decided to wait until a significant weather event occurred.
I was monitoring some thunderstorms on the radar and watched two massive super cells collide directly over the building dumping 8 .76 inches of rain in 15 minutes!
My follow-up investigation the following morning revealed no significant change in water intrusion into the building in comparison to the initial assessment I conduct did on a clear cloudless day with no previous rainfall. waiting for the appropriate moment was a waste of time.
So my recommendation is to begin collecting data as soon as possible regardless of whether you feel the conditions are appropriate.