To isolate the issue, identify the specific circuit that is tripping and turn its breaker to the fully “off” position. A circuit breaker that trips when it rains indicates a serious electrical fault caused by water intrusion. This confirms a ground fault or a short circuit is occurring, meaning the breaker is functioning correctly to protect your home from fire or electrocution hazards. Moisture can damage insulation in underground cables. This may lead to short circuits. From outdoor outlets to buried cables, moisture can slip in through small cracks or gaps, setting off your system's safety response. What Can You Do About It? Inspect Your Outdoor Outlets.