Why does my GFCI periodically trip, especially after a few days’ rain?

Moisture – Moisture anywhere in the line will trip the GFCI. This is the most common problem for outside outlets. Water can get into outdoor electrical boxes if they’re uncovered or if there’s an excessive amount of rain or high humidity. Moisture can also get inside the wiring of an appliance.

How do you fix a GFCI outlet that keeps tripping?

Solution:

1. Remove the GFCI outlet and replace it. If the problem is fixed, then you know that the GFCI was the initial cause of the tripping.
2. If removing the outlet, and the problem persists, it is likely that it could be another outlet on the line, or the circuit breaker itself.