Official observations from Environment Canada at Toronto Pearson International Airport confirm a daily maximum of 27°C on August 18, 2026, aligning with pre-event model consensus that placed mid-August highs in the 27–28°C range under sunny skies and light winds. Lake Ontario’s moderating effect typically limits peaks relative to inland areas, consistent with climatological norms for the period. This measured outcome drove the market-implied probability to 100% once data were verified. Only revised station records, instrument calibration issues, or a shift to a different official reporting site could realistically alter the resolution.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · UpdatedHighest temperature in Toronto on August 18?
Highest temperature in Toronto on August 18?
27°C 100.0%
22°C or below <1%
23°C <1%
24°C <1%
$32,680 Vol.
$32,680 Vol.
Aug 18, 2026
22°C or below
No
23°C
No
24°C
No
25°C
No
26°C
No
27°C
Yes
28°C
No
29°C
No
30°C
No
31°C
No
32°C or higher
No
27°C 100.0%
22°C or below <1%
23°C <1%
24°C <1%
$32,680 Vol.
$32,680 Vol.
Aug 18, 2026
22°C or below
$45 Vol.
No
23°C
$735 Vol.
No
24°C
$1,630 Vol.
No
25°C
$2,852 Vol.
No
26°C
$7,070 Vol.
No
27°C
$8,824 Vol.
Yes
28°C
$6,571 Vol.
No
29°C
$2,343 Vol.
No
30°C
$1,693 Vol.
No
31°C
$798 Vol.
No
32°C or higher
$120 Vol.
No
This market will resolve based on the highest temperature recorded in the 'Daily Observations' table on Weather Underground, not the figure displayed in the 'Day High & Low' summary section; in the event of any discrepancy between the two, the Daily Observations table shall be the primary resolution source not the Day High & Low section.
This market will resolve to the temperature range that contains the highest temperature recorded at the Toronto Pearson Intl Airport Station in degrees Celsius on 18 Aug '26.
The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day for the Toronto Pearson Intl Airport Station, available here: https://www.wunderground.com/history/daily/ca/mississauga/CYYZ.
To toggle between Fahrenheit and Celsius, click the gear icon next to the search bar and switch the Temperature setting between °F and °C.
This market can not resolve until the first data point for the following date has been published on the resolution source.
The resolution source for this market measures temperatures to whole degrees Celsius (eg, 9°C). Thus, this is the level of precision that will be used when resolving the market.
Revisions to temperatures recorded within this market's timeframe will be considered until the first datapoint for the following date has been published, after which any alterations will not be considered.Official observations from Environment Canada at Toronto Pearson International Airport confirm a daily maximum of 27°C on August 18, 2026, aligning with pre-event model consensus that placed mid-August highs in the 27–28°C range under sunny skies and light winds. Lake Ontario’s moderating effect typically limits peaks relative to inland areas, consistent with climatological norms for the period. This measured outcome drove the market-implied probability to 100% once data were verified. Only revised station records, instrument calibration issues, or a shift to a different official reporting site could realistically alter the resolution.
This market will resolve based on the highest temperature recorded in the 'Daily Observations' table on Weather Underground, not the figure displayed in the 'Day High & Low' summary section; in the event of any discrepancy between the two, the Daily Observations table shall be the primary resolution source not the Day High & Low section.
This market will resolve to the temperature range that contains the highest temperature recorded at the Toronto Pearson Intl Airport Station in degrees Celsius on 18 Aug '26.
The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day for the Toronto Pearson Intl Airport Station, available here: https://www.wunderground.com/history/daily/ca/mississauga/CYYZ.
To toggle between Fahrenheit and Celsius, click the gear icon next to the search bar and switch the Temperature setting between °F and °C.
This market can not resolve until the first data point for the following date has been published on the resolution source.
The resolution source for this market measures temperatures to whole degrees Celsius (eg, 9°C). Thus, this is the level of precision that will be used when resolving the market.
Revisions to temperatures recorded within this market's timeframe will be considered until the first datapoint for the following date has been published, after which any alterations will not be considered.
This market will resolve to the temperature range that contains the highest temperature recorded at the Toronto Pearson Intl Airport Station in degrees Celsius on 18 Aug '26.
The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day for the Toronto Pearson Intl Airport Station, available here: https://www.wunderground.com/history/daily/ca/mississauga/CYYZ.
To toggle between Fahrenheit and Celsius, click the gear icon next to the search bar and switch the Temperature setting between °F and °C.
This market can not resolve until the first data point for the following date has been published on the resolution source.
The resolution source for this market measures temperatures to whole degrees Celsius (eg, 9°C). Thus, this is the level of precision that will be used when resolving the market.
Revisions to temperatures recorded within this market's timeframe will be considered until the first datapoint for the following date has been published, after which any alterations will not be considered.
Market Opened: Aug 16, 2026, 9:55 PM ET
Volume
$32,680End Date
Aug 18, 2026Market Opened
Aug 16, 2026, 9:55 PM ETResolution Source
https://www.wunderground.com/history/daily/ca/mississauga/CYYZResolver
0x69c47De9D...Outcome proposed: No
No dispute
Final outcome: No
This market will resolve based on the highest temperature recorded in the 'Daily Observations' table on Weather Underground, not the figure displayed in the 'Day High & Low' summary section; in the event of any discrepancy between the two, the Daily Observations table shall be the primary resolution source not the Day High & Low section.
This market will resolve to the temperature range that contains the highest temperature recorded at the Toronto Pearson Intl Airport Station in degrees Celsius on 18 Aug '26.
The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day for the Toronto Pearson Intl Airport Station, available here: https://www.wunderground.com/history/daily/ca/mississauga/CYYZ.
To toggle between Fahrenheit and Celsius, click the gear icon next to the search bar and switch the Temperature setting between °F and °C.
This market can not resolve until the first data point for the following date has been published on the resolution source.
The resolution source for this market measures temperatures to whole degrees Celsius (eg, 9°C). Thus, this is the level of precision that will be used when resolving the market.
Revisions to temperatures recorded within this market's timeframe will be considered until the first datapoint for the following date has been published, after which any alterations will not be considered.Official observations from Environment Canada at Toronto Pearson International Airport confirm a daily maximum of 27°C on August 18, 2026, aligning with pre-event model consensus that placed mid-August highs in the 27–28°C range under sunny skies and light winds. Lake Ontario’s moderating effect typically limits peaks relative to inland areas, consistent with climatological norms for the period. This measured outcome drove the market-implied probability to 100% once data were verified. Only revised station records, instrument calibration issues, or a shift to a different official reporting site could realistically alter the resolution.
This market will resolve based on the highest temperature recorded in the 'Daily Observations' table on Weather Underground, not the figure displayed in the 'Day High & Low' summary section; in the event of any discrepancy between the two, the Daily Observations table shall be the primary resolution source not the Day High & Low section.
This market will resolve to the temperature range that contains the highest temperature recorded at the Toronto Pearson Intl Airport Station in degrees Celsius on 18 Aug '26.
The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day for the Toronto Pearson Intl Airport Station, available here: https://www.wunderground.com/history/daily/ca/mississauga/CYYZ.
To toggle between Fahrenheit and Celsius, click the gear icon next to the search bar and switch the Temperature setting between °F and °C.
This market can not resolve until the first data point for the following date has been published on the resolution source.
The resolution source for this market measures temperatures to whole degrees Celsius (eg, 9°C). Thus, this is the level of precision that will be used when resolving the market.
Revisions to temperatures recorded within this market's timeframe will be considered until the first datapoint for the following date has been published, after which any alterations will not be considered.
This market will resolve to the temperature range that contains the highest temperature recorded at the Toronto Pearson Intl Airport Station in degrees Celsius on 18 Aug '26.
The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day for the Toronto Pearson Intl Airport Station, available here: https://www.wunderground.com/history/daily/ca/mississauga/CYYZ.
To toggle between Fahrenheit and Celsius, click the gear icon next to the search bar and switch the Temperature setting between °F and °C.
This market can not resolve until the first data point for the following date has been published on the resolution source.
The resolution source for this market measures temperatures to whole degrees Celsius (eg, 9°C). Thus, this is the level of precision that will be used when resolving the market.
Revisions to temperatures recorded within this market's timeframe will be considered until the first datapoint for the following date has been published, after which any alterations will not be considered.
Volume
$32,680End Date
Aug 18, 2026Market Opened
Aug 16, 2026, 9:55 PM ETResolution Source
https://www.wunderground.com/history/daily/ca/mississauga/CYYZResolver
0x69c47De9D...Outcome proposed: No
No dispute
Final outcome: No
Official observations from Environment Canada at Toronto Pearson International Airport confirm a daily maximum of 27°C on August 18, 2026, aligning with pre-event model consensus that placed mid-August highs in the 27–28°C range under sunny skies and light winds. Lake Ontario’s moderating effect typically limits peaks relative to inland areas, consistent with climatological norms for the period. This measured outcome drove the market-implied probability to 100% once data were verified. Only revised station records, instrument calibration issues, or a shift to a different official reporting site could realistically alter the resolution.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · Updated
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