Ottawa's taste of warm spring weather is taking a sharp detour this week, with Thursday temperatures expected to come in at roughly half of what the city basked in just two days ago on Tuesday — and a frost warning overnight making things even chillier.
From Shirtsleeves to Frost in 48 Hours
If you were out enjoying Ottawa's warmth earlier this week, you're not imagining the whiplash. The city is seeing a classic late-May cold snap — the kind that Ottawa residents know all too well — as a cooler air mass pushes through the region and sends the mercury tumbling. Going from unseasonably warm to overnight frost in just two days is a reminder of why locals say you should never put away your winter layers before June.
What This Means for Overnight Hours
The frost risk overnight is the more pressing concern for many Ottawa residents. Gardeners who have already planted tender annuals, herbs, or warm-weather vegetables should take precautions — cover plants with frost cloth, bring in potted plants, or hold off on any new planting until the cold snap passes. The Rideau Valley and rural areas just outside the Greenbelt are typically the most frost-prone, so residents in Kanata, Barrhaven, and Orleans should keep a close eye on overnight lows in their specific area.
Spring in Ottawa: Always a Wild Ride
This week's temperature swing is pretty on-brand for Ottawa springs. The capital sits in a zone where cold Arctic air can still push down well into May, clashing with the warmer air building up from the south. It makes for dramatic swings — warm enough to be in a T-shirt one day, scraping frost off the car the next. Meteorologically speaking, these late-season cold snaps are normal, even if they're frustrating.
How to Ride It Out
A few tips for getting through the cold snap:
- Gardeners: Cover sensitive plants tonight and keep seedlings indoors until overnight lows stabilize above 5°C consistently.
- Cyclists and walkers: Dress in layers — mornings and evenings will feel significantly colder than midweek.
- Drivers: Watch for patchy frost on bridges and overpasses overnight, which can create slippery conditions even when roads otherwise look clear.
- Everyone else: Dig the jacket back out of wherever you shoved it at the back of the closet.
When Does It Warm Up Again?
The good news is that late-May cold snaps in Ottawa tend to be short-lived. Once this system moves through, seasonal warmth typically returns. Keep an eye on Environment and Climate Change Canada's forecast for Ottawa for the latest update on when temperatures are expected to rebound.
In the meantime, this is Ottawa — and as any long-time resident knows, you never fully trust the forecast until you're actually outside.
Source: CTV News Ottawa via Google News
