Fog mixed with heavy downpours expected to saturate Ottawa further
Posted Apr 15, 2026 03:33:41 PM.
Last Updated Apr 16, 2026 09:21:52 AM.
The ground in the nation’s capital is nearly saturated with rainwater, the weather agency is warning, as more precipitation is on its way.
Environment Canada is warning that 10 to 20 millimetres of rain is Thursday, prompted by significant systems travelling across the region. The ground has a “limited capacity” to absorb the additional water, it notes in a statement. The increased moisture in the air has also created dense fog over the city, which is expected to dissipate over the day.
Further downpours are possible the forecast shows, possibly increasing rainfall amounts.
“Water will likely pool on roads and in low-lying areas,” it notes. “Don’t drive through flooded roadways. Avoid low-lying areas.”
It’s prompted the Rideau Valley Conservation Authority (RVCA) to issue a flood outlook for the Lower Ottawa River, which impacts communities from Arnprior to Hawkesbury. This is in response to the already high water levels from the previous rain over the weekend and the existing snowmelt that is moving from the north down the river.
“While there are currently no flooding indicators of concern, it is still too early to forecast peak river conditions which remain dependent on snowmelt and rainfall amounts,” the authority notes.
For communities near the Rideau River in Lanark County, like Perth, people are being asked to closely monitor the waterway. Levels have remained elevated since early April, and reservoirs have limited capacity which could increase the risk of localized flooding.
The Mississippi River watershed is also under a flood watch.
