Why would a 2004 Mazda 6 not run right when it rains?

A 2004 Mazda 6 may not run properly in the rain due to water intrusion in the ignition system, such as the spark plugs, ignition coils, or wiring, which can cause misfires. Another possibility is that moisture is affecting the fuel system or electrical connections, leading to poor engine performance. Additionally, clogged drainage channels or a malfunctioning weather seal could allow water to enter areas where it shouldn't, exacerbating the issue. Regular maintenance and inspections can help identify and resolve these problems.