OTTAWA -- The middle of the Civic Holiday long weekend is a rainy one.

Environment Canada's weather forecast for Ottawa includes showers throughout the day, with up to 25 mm expected.

To the west of Ottawa, rainfall warnings are in effect for parts of the Ottawa Valley, including Renfrew, Arnprior, Petawawa, Pembroke, and Calabogie. Environment Canada warns the region could see between 50 and 60 mm of rain Sunday, with the possibility of some regions seeing up to 75 mm.

"Heavy downpours can cause flash floods and water pooling on roads. If visibility is reduced while driving, slow down, watch for taillights ahead and be prepared to stop," Environment Canada warned.

Ottawa forecast

Sunday: 15 to 25 mm of rain with a high of 26°C, humidex of 34. There is a risk of a severe thunderstorm in the afternoon.

Overnight: Showers, with a few thunderstorms ending late in the evening, then cloudy with a 60 per cent chance of showers after midnight. Low 17°C.

Monday: Mainly cloudy with a 40 per cent chance of showers in the morning. High 23°C with a humidex of 30.

Tuesday: Cloudy with a 70 per cent chance of showers. High 21°C.

Wednesday: Sun/cloud mix with a 30 per cent chance of showers. High 22°C