Heavy rain can be expected into Thursday night with a rainfall warning in effect for multiple parts of Vancouver Island and the Sunshine Coast.
Anywhere between 50 and 100 millimetres of rain is forecast for east Vancouver Island from Campbell River to Nanoose Bay and Powell River to Gibsons.
Environment and Climate Change Canada says a frontal system will make the rain at times heavy before easing off on Friday.
They add the downpours can cause flash floods, localized flooding in low-lying areas, water pooling on roads and reduced visibility while driving.
If visibility is reduced, they say to turn on your headlights and keep a safe following distance.
Drivers are also asked to watch out for possible washouts near rivers, creeks and culverts.