Areas hardest hit will be between Port Moody and Maple Ridge which are expected to receive 50 mm of rain.
The weather forecaster says the rain should ease by Tuesday morning.
Environment Canada issued the warning Sunday.
Heavy downpours can cause flash floods and pooling water on roads.
Environment Canada meteorologists will update weather alerts as required.
Reports of severe weather can be emailed to firstname.lastname@example.org or tweeted with the hashtag #BCStorm.