Official forecasts from Environment Canada indicate sunny conditions and a daytime high near 31°C for Toronto on May 18, driving the market's tight clustering around 30°C and 31°C outcomes. Numerical weather prediction models show modest spread due to variable springtime steering flows and boundary-layer mixing, with some ensembles favoring slight cooling from lingering marine influences while others project modest warming under high pressure. Historical May climatology places average highs around 18–20°C, so current guidance reflects a notable positive anomaly supported by recent upstream ridging. Traders weigh these model discrepancies against potential afternoon convective development that could cap peak readings, leaving probabilities closely balanced ahead of final observational verification.
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?
30°C 28%
32°C or higher 22%
31°C 22%
29°C 21%
NEW
$16,497 Vol.
NEW
$16,497 Vol.
May 18, 2026
22°C or below
<1%
23°C
1%
24°C
<1%
25°C
1%
26°C
1%
27°C
3%
28°C
7%
29°C
21%
30°C
28%
31°C
22%
32°C or higher
22%
30°C 28%
32°C or higher 22%
31°C 22%
29°C 21%
NEW
$16,497 Vol.
NEW
$16,497 Vol.
May 18, 2026
22°C or below
$4,281 Vol.
<1%
23°C
$1,116 Vol.
1%
24°C
$1,608 Vol.
<1%
25°C
$837 Vol.
1%
26°C
$1,532 Vol.
1%
27°C
$873 Vol.
3%
28°C
$1,736 Vol.
7%
29°C
$1,495 Vol.
21%
30°C
$658 Vol.
28%
31°C
$878 Vol.
22%
32°C or higher
$1,522 Vol.
22%
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.Official forecasts from Environment Canada indicate sunny conditions and a daytime high near 31°C for Toronto on May 18, driving the market's tight clustering around 30°C and 31°C outcomes. Numerical weather prediction models show modest spread due to variable springtime steering flows and boundary-layer mixing, with some ensembles favoring slight cooling from lingering marine influences while others project modest warming under high pressure. Historical May climatology places average highs around 18–20°C, so current guidance reflects a notable positive anomaly supported by recent upstream ridging. Traders weigh these model discrepancies against potential afternoon convective development that could cap peak readings, leaving probabilities closely balanced ahead of final observational verification.
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
$16,497End 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.Official forecasts from Environment Canada indicate sunny conditions and a daytime high near 31°C for Toronto on May 18, driving the market's tight clustering around 30°C and 31°C outcomes. Numerical weather prediction models show modest spread due to variable springtime steering flows and boundary-layer mixing, with some ensembles favoring slight cooling from lingering marine influences while others project modest warming under high pressure. Historical May climatology places average highs around 18–20°C, so current guidance reflects a notable positive anomaly supported by recent upstream ridging. Traders weigh these model discrepancies against potential afternoon convective development that could cap peak readings, leaving probabilities closely balanced ahead of final observational verification.
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
$16,497End Date
May 18, 2026Market Opened
May 16, 2026, 12:03 AM ETResolution Source
https://www.wunderground.com/history/daily/ca/mississauga/CYYZOfficial forecasts from Environment Canada indicate sunny conditions and a daytime high near 31°C for Toronto on May 18, driving the market's tight clustering around 30°C and 31°C outcomes. Numerical weather prediction models show modest spread due to variable springtime steering flows and boundary-layer mixing, with some ensembles favoring slight cooling from lingering marine influences while others project modest warming under high pressure. Historical May climatology places average highs around 18–20°C, so current guidance reflects a notable positive anomaly supported by recent upstream ridging. Traders weigh these model discrepancies against potential afternoon convective development that could cap peak readings, leaving probabilities closely balanced ahead of final observational verification.
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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