Why does your internet slow down when it rains?

DSL internet can be a pain in the butt. You're running your internet over copper phone cables that have possibly been in the ground or hanging off power poles for decades. They could be over a century old. The speeds can seriously suck, and when it rains the speed can drop exponentially.

It's not an effective material for transmitting internet signal over long distances - it was designed for voice communication only when switchboards would effectively connect telephones to each other via one very long cable.

Remember using old dialup modems? The concept is the same for them - they just used a digital signal rather than an analogue one.

Unlike fibre optic cable which transmits using light, or wireless which uses radiation in the form of radio frequencies through the air, the copper system uses electricity as the old phones did.

So that explains why copper's the least desirable option in general, but why do speeds tank when it rains?

If you're one of the many that has below-ground cabling, then these are the two main reasons:

  • Copper conducts electricity

  • It's buried below ground or it’s hanging off telephone poles

A shiny new example of a trap installed by the NBN

A shiny new example of a trap installed by the NBN


When rainwater enters the cable 'traps' your cable connects to, it limits the conductivity of your cable. When submersed in water - which is an electrical conductor - then the current breaks down and dilutes the electrical signal. This effectively means that your connection gets weaker and your speed slows.

The solution?

Replace your copper or FTTN internet connection with a wireless system - cut the cord and ditch the copper cable network. Switchnode can help you with that so get in touch for full details!

Nathan Smith Author for Switchnode

Nathan Smith
Author for Switchnode