Ontario weather in September

Are you planning a trip to Ontario in September and wondering what kind of weather to expect? This page has all the details you need.

What is the weather like in Ontario in September?

Ontario is a region in Canada. September in Ontario generally has temperatures that range from moderate to warm, with precipitation levels ranging from moderate to high. During September, summer is in full swing.

During the day temperatures vary from moderate in Niagara on the Lake at 17°C to warm in Chatham at 24°C. At night it cools down to 14°C in Chatham and 9°C in Niagara on the Lake.

In September, precipitation varies across different areas. From moderate rainfall in Niagara on the Lake with an average of 60 mm to high rainfall in Schreiber with 127 mm. The days are mostly sunny, with an average total of around 195 hours of sunshine in Toronto. The sunlight during this month doesn't just make the days brighter, it also seems to make everyone a bit more cheerful.

To learn more about the conditions in specific areas of Ontario in September, check out the map below. For more details on the yearly weather, visit our Ontario climate page.

Where to go in Ontario in September

Find the average weather conditions in September for the most popular destinations in Ontario on the map below. Click on a destination dot for more detailed information.

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Legend perfect weather pleasant tolerable unpleasant poor
Perfect weather is subjective. On this map perfect weather has been defined with temperatures between 20°C and 29°C and not too much precipitation (less than 90 mm a month).

Popular destinations in Ontario

What is the weather like in September for the 5 most popular destinations in Ontario?

Average weather in Toronto

In September Toronto generally has high temperatures with maximum daytime temperatures around 22°C, minimum nighttime temperatures around 15°C and moderate monthly rainfall. So on average the conditions are perfect that month.

Toronto
minimum temparatureMax temperature minimum temparatureMax temp
maximum temparatureMin temperature maximum temparatureMin temp
sun hoursMonthly sun hours sun hoursSun hours
precipitationMonthly rainfall precipitationRainfall
rain daysMonthly rainy days rain daysRainy days
conditionsWeather conditions conditionsWeather
<<   August August
<<  
26°C 
18°C 
245 hours 
68 mm 
10 days 
22°C 
15°C 
195 hours 
83 mm 
10 days 
October   >> October
>>  
16°C 
8°C 
160 hours 
91 mm 
11 days 
Climate in Toronto

Average weather in Ottawa

In September Ottawa generally has high temperatures with maximum daytime temperatures around 22°C, minimum nighttime temperatures around 10°C and moderate monthly rainfall. So on average the conditions are perfect that month.

Ottawa
minimum temparatureMax temperature minimum temparatureMax temp
maximum temparatureMin temperature maximum temparatureMin temp
sun hoursMonthly sun hours sun hoursSun hours
precipitationMonthly rainfall precipitationRainfall
rain daysMonthly rainy days rain daysRainy days
conditionsWeather conditions conditionsWeather
<<   August August
<<  
26°C 
14°C 
251 hours 
94 mm 
11 days 
22°C 
10°C 
178 hours 
99 mm 
12 days 
October   >> October
>>  
14°C 
4°C 
138 hours 
102 mm 
12 days 
Climate in Ottawa

Average weather in Niagara Falls

In September Niagara Falls generally has high temperatures with maximum daytime temperatures around 23°C, minimum nighttime temperatures around 13°C and moderate monthly rainfall. So on average the conditions are perfect that month.

Niagara Falls
minimum temparatureMax temperature minimum temparatureMax temp
maximum temparatureMin temperature maximum temparatureMin temp
sun hoursMonthly sun hours sun hoursSun hours
precipitationMonthly rainfall precipitationRainfall
rain daysMonthly rainy days rain daysRainy days
conditionsWeather conditions conditionsWeather
<<   August August
<<  
26°C 
17°C 
268 hours 
67 mm 
11 days 
23°C 
13°C 
206 hours 
86 mm 
12 days 
October   >> October
>>  
15°C 
7°C 
158 hours 
103 mm 
15 days 
Climate in Niagara Falls

Average weather in Mississauga

In September Mississauga generally has high temperatures with maximum daytime temperatures around 23°C, minimum nighttime temperatures around 13°C and moderate monthly rainfall. So on average the conditions are perfect that month.

Mississauga
minimum temparatureMax temperature minimum temparatureMax temp
maximum temparatureMin temperature maximum temparatureMin temp
sun hoursMonthly sun hours sun hoursSun hours
precipitationMonthly rainfall precipitationRainfall
rain daysMonthly rainy days rain daysRainy days
conditionsWeather conditions conditionsWeather
<<   August August
<<  
26°C 
17°C 
276 hours 
69 mm 
9 days 
23°C 
13°C 
216 hours 
80 mm 
9 days 
October   >> October
>>  
15°C 
7°C 
165 hours 
86 mm 
10 days 
Climate in Mississauga

Average weather in Niagara on the Lake

In September Niagara on the Lake generally has moderate temperatures with maximum daytime temperatures around 17°C, minimum nighttime temperatures around 9°C and moderate monthly rainfall. So on average the conditions are tolerable that month.

Niagara on the Lake
minimum temparatureMax temperature minimum temparatureMax temp
maximum temparatureMin temperature maximum temparatureMin temp
sun hoursMonthly sun hours sun hoursSun hours
precipitationMonthly rainfall precipitationRainfall
rain daysMonthly rainy days rain daysRainy days
conditionsWeather conditions conditionsWeather
<<   August August
<<  
20°C 
12°C 
268 hours 
47 mm 
8 days 
17°C 
9°C 
206 hours 
60 mm 
9 days 
October   >> October
>>  
12°C 
5°C 
158 hours 
64 mm 
11 days 
Climate in Niagara on the Lake

Is your destination not in the list? Have a look at other destinations in Ontario, in Canada.

Is September the best time to visit Ontario?

We consider September to be one of the best times to travel to Ontario. Typically, the climate in Toronto is perfect. However, the weather conditions may vary depending on your destination.

Generally speaking, the best visiting conditions can be found in June, July, August and September offering mostly perfect weather in Toronto. The weather in January, February, March, April, November and December, on the other hand, tends to be poor.

Interested in more climate information?

We have much more information about the climate in Ontario. Interested in the weather conditions in a specific month? Select the month below.

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  • Weather and climate has detailed information for every country in the world. Are you going to Canada? Get detailed historical weather averages for many cities in Canada.

    Not sure yet where to go? We now have a tool which recommends destinations that suit your ideal climate conditions. Find out where to go with our weather planner.