Ottawa Rainfall Warning in Effect
Ottawa is being put on notice: Environment Canada has issued an official rainfall warning for the city, with forecasters calling for 30 to 50 millimetres of rain to fall overnight into Thursday morning. That's a significant amount of precipitation in a short window — the kind that can quickly overwhelm storm drains, flood low-lying areas, and make commuting genuinely miserable.
The warning covers Ottawa and surrounding communities, meaning whether you're in Kanata, Gloucester, Barrhaven, or the downtown core, you'll want to plan accordingly before the rain rolls in tonight.
What to Expect
Heavy rainfall in the 30–50 mm range over such a short period puts stress on Ottawa's drainage infrastructure. Residents in areas prone to basement flooding or near waterways like the Rideau River and Ottawa River tributaries should take extra precautions.
Here's what forecasters are warning about:
- Rapidly accumulating water on roads and in low-lying neighbourhoods
- Reduced visibility during the heaviest downpours, particularly overnight and during Thursday's morning rush
- Slippery surfaces and standing water on major routes, bike paths, and sidewalks
- Possible localized flooding in basements and underpasses
If you have a sump pump, now's the time to make sure it's working.
Getting Around Ottawa on Thursday
Thursday's morning commute could be rough. OC Transpo routes and LRT service typically hold up in rain, but street-level delays from traffic and flooding on surface roads are always possible during heavy events. If you're driving, give yourself extra time and watch for ponding water — it's deeper than it looks.
Cyclists on the NCC pathways and recreational trails should expect waterlogged conditions. Many multi-use paths along the canal and river fronts drain slowly after heavy rain, so muddy or flooded sections are likely by morning.
How to Prepare
A few simple steps can make a big difference when a significant rainfall event is headed your way:
- Move valuable items out of basements or off of basement floors
- Clear leaves and debris from your eavestroughs and downspouts
- Avoid parking in known flood-prone underpasses or low-lying lots
- Keep an eye on the City of Ottawa's social media and Ottawa Police Service accounts for any road closure updates
- If you live near the Rideau or Ottawa rivers, check Ottawa Riverkeeper and the City's flood status page for water level updates
When Will It Clear?
The bulk of the rainfall is expected overnight and through Thursday, with conditions gradually improving heading into the weekend. After a wet stretch, Ottawa typically bounces back quickly — but that first dry day after a big rain event is prime time for pothole complaints on social media, so fair warning there too.
Stay dry, Ottawa. Grab an umbrella, bookmark the weather radar, and maybe hold off on that patio dinner until Friday.
Source: CTV News Ottawa / Google News Ottawa. Rainfall warning information sourced from Environment Canada.
