The Canadian Environmental Agency has issued a rain warning in Ottawa starting this morning, Saturday.

The meteorological agency expects rainfall between 40 to 60 mm over the weekend.

The meteorological agency stated in a press release that a low-pressure system will bring heavy rainfall to the area this weekend, and regions receiving multiple thunderstorms may exceed 60 mm locally.

"Heavy rainfall can cause flash floods and pooling of water on roads. Local flooding is likely in low-lying areas.

The rainfall follows a heatwave that lasted four days with temperatures exceeding 30 degrees Celsius and humidity making it feel like 40 degrees. The Canadian Environmental Ministry lifted the heat warning on Friday.

Temperatures are expected to reach 20 degrees Celsius, with a few showers starting early Saturday morning and ending in the afternoon, according to the Canadian Environmental Ministry, with a drop in temperatures to 16 degrees Celsius, with heavy rains occasionally starting this evening, and a thunderstorm is expected late tonight.

On Sunday, maximum temperatures in the capital are expected to reach 23 degrees Celsius with a humidity level of 32.

Heavy rainfall is also expected at times with a risk of thunderstorms. Temperatures are expected to reach 16 degrees Celsius, with a 60 percent chance of rain overnight.

The sky is expected to be cloudy, with a 40 percent chance of rain, and a maximum temperature reaching 24 degrees on Monday.

The sky is expected to be clear, with the lowest temperature expected to reach 16 degrees on Monday night into Tuesday.