How reliable is Ottawa Macdonald-Cartier International Airport?
Month-by-month weather risk and connection guidance for Ottawa Macdonald-Cartier International Airport. We don’t yet have on-time performance history here — see why below.
Weather favorability
year-round climate
On-time performance data isn’t available for YOW yet
Our historical on-time and cancellation record currently covers the US, UK, Brazil, and Australia, so we don’t score departure reliability at Ottawa Macdonald-Cartier International Airport yet. Weather climatology below comes from global airport observations and still applies.
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Weather by month
When the weather works for you at Ottawa
A calm-weather score (0–100) for each month from decades of airport observations — how often conditions disrupt flying, not temperature. Higher is calmer.
Calmest month
Calmest flying weather of the year · 97/100 favorability
Roughest month
Most disruptive — snow, low visibility & fog · 77/100 favorability
The read on YOW
What the numbers say about flying through Ottawa Macdonald-Cartier International Airport
PlaneSane doesn't yet have on-time and cancellation history for Ottawa Macdonald-Cartier International Airport, so it isn't scored for departure reliability here — that record currently covers the US, UK, Brazil, and Australia. The weather and connection context below comes from separate global sources and still applies.
On weather, Ottawa is an unusually calm-weather airport year-round. May is the calmest stretch for flying, scoring 97 out of 100 for favorable conditions, while December is the most disruptive at 77, driven mainly by snow and low visibility & fog. The seasonal swing is real but manageable; favor the calmer months when your dates are flexible.
None of this guarantees your specific flight — it’s the backdrop. To turn it into a booking, score real flights to Ottawa, read how we weigh it all in how the PlaneSane Score works, and brush up with how to pick a reliable flight and avoiding weather delays.
Common questions about YOW
- What is the best month to fly from YOW for good weather?
- May has the calmest flying weather at Ottawa Macdonald-Cartier International Airport. December is the most disruptive, mainly from snow and low visibility & fog.
Planning a trip through Ottawa?
Score real flights to and from YOW on reliability, weather, and connection safety — not just price.