Official forecasts from Brazil’s National Institute of Meteorology (INMET) and global model ensembles confirmed a daily maximum of 18 °C in São Paulo on May 23, consistent with late-autumn high-pressure dominance that suppressed daytime heating and limited cloud cover. Typical May climatology shows average highs near 22–23 °C, yet an advancing polar air mass and clear radiative cooling overnight produced cooler surface conditions that aligned precisely with the observed peak. Traders assigned near-100 % implied probability to 18 °C because verified station data and post-event verification matched this threshold exactly. A realistic challenge would require an official data revision from INMET or a previously unreported localized heat spike exceeding measurement uncertainty, both of which remain unlikely given the stability of the observing network.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · UpdatedHighest temperature in Sao Paulo on May 23?
Highest temperature in Sao Paulo on May 23?
18°C 100.0%
11°C or below <1%
12°C <1%
13°C <1%
$58,895 Vol.
$58,895 Vol.
May 23, 2026
11°C or below
No
12°C
No
13°C
No
14°C
No
15°C
No
16°C
No
17°C
No
18°C
Yes
19°C
No
20°C
No
21°C or higher
No
18°C 100.0%
11°C or below <1%
12°C <1%
13°C <1%
$58,895 Vol.
$58,895 Vol.
May 23, 2026
11°C or below
$500 Vol.
No
12°C
$537 Vol.
No
13°C
$1,331 Vol.
No
14°C
$797 Vol.
No
15°C
$4,022 Vol.
No
16°C
$7,452 Vol.
No
17°C
$12,628 Vol.
No
18°C
$12,136 Vol.
Yes
19°C
$7,067 Vol.
No
20°C
$5,210 Vol.
No
21°C or higher
$7,214 Vol.
No
This market will resolve to the temperature range that contains the highest temperature recorded at the Sao Paulo-Guarulhos International Airport Station in degrees Celsius on 23 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 Sao Paulo-Guarulhos International Airport Station once information is finalized, available here: https://www.wunderground.com/history/daily/br/guarulhos/SBGR.
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 Brazil’s National Institute of Meteorology (INMET) and global model ensembles confirmed a daily maximum of 18 °C in São Paulo on May 23, consistent with late-autumn high-pressure dominance that suppressed daytime heating and limited cloud cover. Typical May climatology shows average highs near 22–23 °C, yet an advancing polar air mass and clear radiative cooling overnight produced cooler surface conditions that aligned precisely with the observed peak. Traders assigned near-100 % implied probability to 18 °C because verified station data and post-event verification matched this threshold exactly. A realistic challenge would require an official data revision from INMET or a previously unreported localized heat spike exceeding measurement uncertainty, both of which remain unlikely given the stability of the observing network.
This market will resolve to the temperature range that contains the highest temperature recorded at the Sao Paulo-Guarulhos International Airport Station in degrees Celsius on 23 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 Sao Paulo-Guarulhos International Airport Station once information is finalized, available here: https://www.wunderground.com/history/daily/br/guarulhos/SBGR.
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 Sao Paulo-Guarulhos International Airport Station once information is finalized, available here: https://www.wunderground.com/history/daily/br/guarulhos/SBGR.
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 21, 2026, 6:05 AM ET
Volume
$58,895End Date
May 23, 2026Market Opened
May 21, 2026, 6:05 AM ETResolution Source
https://www.wunderground.com/history/daily/br/guarulhos/SBGRResolver
0x69c47De9D...Outcome proposed: No
No dispute
Final outcome: No
This market will resolve to the temperature range that contains the highest temperature recorded at the Sao Paulo-Guarulhos International Airport Station in degrees Celsius on 23 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 Sao Paulo-Guarulhos International Airport Station once information is finalized, available here: https://www.wunderground.com/history/daily/br/guarulhos/SBGR.
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 Brazil’s National Institute of Meteorology (INMET) and global model ensembles confirmed a daily maximum of 18 °C in São Paulo on May 23, consistent with late-autumn high-pressure dominance that suppressed daytime heating and limited cloud cover. Typical May climatology shows average highs near 22–23 °C, yet an advancing polar air mass and clear radiative cooling overnight produced cooler surface conditions that aligned precisely with the observed peak. Traders assigned near-100 % implied probability to 18 °C because verified station data and post-event verification matched this threshold exactly. A realistic challenge would require an official data revision from INMET or a previously unreported localized heat spike exceeding measurement uncertainty, both of which remain unlikely given the stability of the observing network.
This market will resolve to the temperature range that contains the highest temperature recorded at the Sao Paulo-Guarulhos International Airport Station in degrees Celsius on 23 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 Sao Paulo-Guarulhos International Airport Station once information is finalized, available here: https://www.wunderground.com/history/daily/br/guarulhos/SBGR.
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 Sao Paulo-Guarulhos International Airport Station once information is finalized, available here: https://www.wunderground.com/history/daily/br/guarulhos/SBGR.
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
$58,895End Date
May 23, 2026Market Opened
May 21, 2026, 6:05 AM ETResolution Source
https://www.wunderground.com/history/daily/br/guarulhos/SBGRResolver
0x69c47De9D...Outcome proposed: No
No dispute
Final outcome: No
Official forecasts from Brazil’s National Institute of Meteorology (INMET) and global model ensembles confirmed a daily maximum of 18 °C in São Paulo on May 23, consistent with late-autumn high-pressure dominance that suppressed daytime heating and limited cloud cover. Typical May climatology shows average highs near 22–23 °C, yet an advancing polar air mass and clear radiative cooling overnight produced cooler surface conditions that aligned precisely with the observed peak. Traders assigned near-100 % implied probability to 18 °C because verified station data and post-event verification matched this threshold exactly. A realistic challenge would require an official data revision from INMET or a previously unreported localized heat spike exceeding measurement uncertainty, both of which remain unlikely given the stability of the observing network.
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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