Why is the broadband always disconnected on rainy days?

In rainy weather, broadband data transmission will be affected by the weather, so the network will be disconnected. Especially in thunderstorm weather, the network at this time will inevitably be affected. In addition, broadband has been used for a long time, and the network is disconnected when it rains. Then you might as well change the network cable, which may try to avoid the phenomenon of network disconnection in rainy days.