Average Daily Maximum Temperature – Minimum – Sunshine – Raindays – Snowdays – Snowdepth – Windspeed
Ottawa lies farther north than Toronto, resulting in significantly colder winters.
Unlike many of Ontario’s cities, Ottawa does not sit on the shores of Lake Ontario. This results in higher summer temperatures in Ottawa but increases the harshness of the winters.
Ottawa has a semi-continental climate, with a warm, humid summer and a very cold winter.
Winters in Ottawa are severe. Snow depths of greater than 1 cm are seen on about 120 days each year compared with about 65 days in Toronto. Much greater depths of snow are also found in Ottawa than Toronto.
Ottawa, like other cities in Ontario, enjoys a sunny climate. Summers usually have a generous number of warm or hot sunny days.
Winters are rather less sunny than in the prairie cities of Calgary and Winnipeg.
Ottawa suffers less smog than Toronto. Air quality can be classed as very good, good, moderate, poor or very poor. In 2012, Ottawa had 29 days of moderate air quality. The rest were good or very good.
Ottawa’s day-to day-weather can be changeable throughout the year.
Ottawa, Ontario
| Month of year  |
Av. Daily Max. Temp. (°C)  |
Av. Daily Min. Temp. (°C)  |
Av. hours Sun (per day)  |
Av. Days with Rain  |
Av. Days with Snowfall  |
Av. Depth Snow on Ground (cm)  |
Av. Wind Speed (km per hr)  |
|---|---|---|---|---|---|---|---|
| Jan. | -6 | -15 | 3.3 | 4 | 15 | 21 | 14 |
| Feb. | -4 | -13 | 4.4 | 3 | 11 | 25 | 14 |
| Mar. | 2 | -7 | 5.2 | 6 | 8 | 20 | 14 |
| Apr. | 11 | 1 | 6.3 | 11 | 3 | 2 | 14 |
| May | 19 | 8 | 7.4 | 13 | 0 | 0 | 12 |
| Jun. | 24 | 13 | 8.4 | 13 | 0 | 0 | 11 |
| Jul. | 26 | 15 | 8.9 | 12 | 0 | 0 | 10 |
| Aug. | 25 | 14 | 8.0 | 12 | 0 | 0 | 9 |
| Sep. | 20 | 10 | 5.7 | 14 | 0 | 0 | 10 |
| Oct. | 12 | 4 | 4.4 | 14 | 1 | 0 | 12 |
| Nov. | 5 | -2 | 2.8 | 11 | 5 | 1 | 13 |
| Dec. | -3 | -10 | 2.6 | 5 | 13 | 11 | 13 |
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Most of eastern Ontario’s moisture gets pulled up from the Gulf of Mexico and the eastern U.S. seaboard, and a lesser amount from the Great Lakes and James Bay. https://www.canada.ca/en/environment-climate-change/services/sky-watchers/publications/guide/chapter-2.html
I think the humidity is caused by the fact that most of the air massed that move into the area are from the gulf of Mexico and the fact that the temperature of this air declines as it moves north, raising the relative humidity to close to 100%
I think the humidity in the summer is worse because we live in a valley and the air gets trapped. Try driving home in the summer after being out of town, you can feel it descending like a heavy blanket! But our summers are gorgeous anyway. I find the winters long, but that’s because I’m older and don’t do winter activities. Ottawa is a very good and safe city to live in and raise a family.
I find the weather in Ottawa can be awful or wonderful depending on the activities. Summers are humid and hot – but if you have air conditioning at home and spend your time outside mostly on the water (boating, swimming) then it’s really perfect weather.
Fall is wonderful (foliage colors and weather make hiking pure enjoyment).
Winters can be harsh and long with lots of snow. But if you are into skiing – both cross-country and downhill – you would appreciate all that snow.
I also find that Ottawa is less windy than Toronto or Montreal
Ottawa summers are perfect for pool, beach and cottages. Being by the water with hot sunny humid days is second to none. Winters can be hard but it changes nearly every year. Winter 2020 was a breeze to go through. Mostly mild and enough snow to have tons of fun but it all disappeared by the beginning of April. Summer 2020 was amazing and would’nt of wanted to be locked down anywhere else. I anticipate summer 2021 to be similar. Things are good in Ottawa overall as city. Being surrounded by huge parks, mountains and beautiful air quality make a very likable and livable city.
What are the “mountains” that Ottawa is
“surrounded by”?
Gatineau hills (ancient mountains) on the north side. And the city is in a valley so going south or southwest you climb out of the city.
Born and raised in Ottawa, I love this clean city. But when it comes to weather, we have to admit it is usually not good. It’s like hurry up to mow the lawn before sucky weather comes back.
I so agree with you on all aspect I lived in Ottawa and surroundings all my life and have no complaints whatsoever about our weather which is a perfect 4 season. My only drawback is the time change. I only hope that someday we will get that extra hour of daylight in autumn
Ottawa has the worst weather year round. Winters are cold and harsh, Spring is rainy to the point of flooding, Summer is humid and miserable and Fall is more rain, damp and cold. It is accurate to say Ottawa has the worst weather of all cities in Canada.
Huh??? I’ve lived in Ottawa 50 years and I think you exaggerate. Rainy til it floods? 🤦♀️Any floods in the spring are from melting snow, not rain.
An utterly absurd comment – in Edmonton and Calgary temperatures plummet to minus 45.
I’ve lived in Ottawa for 45 years and I’ve noted that no matter how dull and dreary days are for sometimes mes 7 days in a row but ever day at around 5-6pm, the sun comes out and then it’s gone? I have been curious about this forever so I thought it wouldn’t hurt to ask an expert because it has boggled my mind forever and wonder if there’s a reason why this happens
2nd question is why is Ottawa humidity level mostly always high no matter if the suns out… it’s snowing or raining out or if it’s a clear day. The reason I ask is that I suffer from Rheumatoid arthritis, osteoarthritis and fibromyalgia and I really believe I suffer to death nearly everyday but because the humidex is always so high… does that play a part in my pain threshold? I was born and raised inNorth Bay, Ontario and did not suffer like I’ve suffered since moving to Ottawa 45 years ago. The older I get the worse it gets for me…..would the weather be playing a big part in why I suffer so severely?
I want to Thankyou in advance for a response to these dilemmas and tell you how much I appreciate you looking into this problem for me
Sincerely,
Laurie L Collins
I believe the high humidity is caused from being North East of the massive fresh water deposits of the Great Lakes as the jet stream carries through them and towards Ottawa a lot of the time.