Recent forecast models from Environment Canada and major meteorological agencies show a warming trend across southern Ontario driven by a strengthening high-pressure system and southerly flow of warmer air, positioning Toronto's May 18 daytime high near 29–30 °C. Ensemble guidance indicates limited cloud cover and minimal precipitation risk, supporting the market's tight clustering between 28 °C and 31 °C outcomes while assigning lower probability to 32 °C or higher due to modest model spread on peak mixing ratios. Historical May climatology for the region places typical highs around 18–20 °C, so the current anomaly reflects a transient ridge that could shift with any late adjustment in the 500 hPa pattern. Updated model runs expected within the next 24 hours will further refine the exact maximum.
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 May 18?
Highest temperature in Toronto on May 18?
29°C 29%
30°C 26%
31°C 16%
28°C 14%
NEW
NEW
May 18, 2026
22°C or below
<1%
23°C
<1%
24°C
1%
25°C
1%
26°C
5%
27°C
8%
28°C
14%
29°C
29%
30°C
26%
31°C
16%
32°C or higher
12%
29°C 29%
30°C 26%
31°C 16%
28°C 14%
NEW
NEW
May 18, 2026
22°C or below
$963 Vol.
<1%
23°C
$548 Vol.
<1%
24°C
$453 Vol.
1%
25°C
$107 Vol.
1%
26°C
$109 Vol.
5%
27°C
$145 Vol.
8%
28°C
$314 Vol.
14%
29°C
$267 Vol.
29%
30°C
$145 Vol.
26%
31°C
$232 Vol.
16%
32°C or higher
$500 Vol.
12%
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 May '26.
The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day by the Forecast for the Toronto Pearson Intl Airport Station once information is finalized, 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 to "Yes" until all data for this date has been finalized.
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.
Any revisions to temperatures recorded after data is finalized for this market's timeframe will not be considered for this market's resolution.Recent forecast models from Environment Canada and major meteorological agencies show a warming trend across southern Ontario driven by a strengthening high-pressure system and southerly flow of warmer air, positioning Toronto's May 18 daytime high near 29–30 °C. Ensemble guidance indicates limited cloud cover and minimal precipitation risk, supporting the market's tight clustering between 28 °C and 31 °C outcomes while assigning lower probability to 32 °C or higher due to modest model spread on peak mixing ratios. Historical May climatology for the region places typical highs around 18–20 °C, so the current anomaly reflects a transient ridge that could shift with any late adjustment in the 500 hPa pattern. Updated model runs expected within the next 24 hours will further refine the exact maximum.
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 May '26.
The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day by the Forecast for the Toronto Pearson Intl Airport Station once information is finalized, 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 to "Yes" until all data for this date has been finalized.
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.
Any revisions to temperatures recorded after data is finalized for this market's timeframe will not be considered for this market's resolution.
The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day by the Forecast for the Toronto Pearson Intl Airport Station once information is finalized, 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 to "Yes" until all data for this date has been finalized.
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.
Any revisions to temperatures recorded after data is finalized for this market's timeframe will not be considered for this market's resolution.
Market Opened: May 16, 2026, 12:03 AM ET
Volume
$3,784End Date
May 18, 2026Market Opened
May 16, 2026, 12:03 AM ETResolution Source
https://www.wunderground.com/history/daily/ca/mississauga/CYYZThis 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 May '26.
The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day by the Forecast for the Toronto Pearson Intl Airport Station once information is finalized, 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 to "Yes" until all data for this date has been finalized.
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.
Any revisions to temperatures recorded after data is finalized for this market's timeframe will not be considered for this market's resolution.Recent forecast models from Environment Canada and major meteorological agencies show a warming trend across southern Ontario driven by a strengthening high-pressure system and southerly flow of warmer air, positioning Toronto's May 18 daytime high near 29–30 °C. Ensemble guidance indicates limited cloud cover and minimal precipitation risk, supporting the market's tight clustering between 28 °C and 31 °C outcomes while assigning lower probability to 32 °C or higher due to modest model spread on peak mixing ratios. Historical May climatology for the region places typical highs around 18–20 °C, so the current anomaly reflects a transient ridge that could shift with any late adjustment in the 500 hPa pattern. Updated model runs expected within the next 24 hours will further refine the exact maximum.
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 May '26.
The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day by the Forecast for the Toronto Pearson Intl Airport Station once information is finalized, 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 to "Yes" until all data for this date has been finalized.
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.
Any revisions to temperatures recorded after data is finalized for this market's timeframe will not be considered for this market's resolution.
The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day by the Forecast for the Toronto Pearson Intl Airport Station once information is finalized, 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 to "Yes" until all data for this date has been finalized.
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.
Any revisions to temperatures recorded after data is finalized for this market's timeframe will not be considered for this market's resolution.
Volume
$3,784End Date
May 18, 2026Market Opened
May 16, 2026, 12:03 AM ETResolution Source
https://www.wunderground.com/history/daily/ca/mississauga/CYYZRecent forecast models from Environment Canada and major meteorological agencies show a warming trend across southern Ontario driven by a strengthening high-pressure system and southerly flow of warmer air, positioning Toronto's May 18 daytime high near 29–30 °C. Ensemble guidance indicates limited cloud cover and minimal precipitation risk, supporting the market's tight clustering between 28 °C and 31 °C outcomes while assigning lower probability to 32 °C or higher due to modest model spread on peak mixing ratios. Historical May climatology for the region places typical highs around 18–20 °C, so the current anomaly reflects a transient ridge that could shift with any late adjustment in the 500 hPa pattern. Updated model runs expected within the next 24 hours will further refine the exact maximum.
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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