Latest INMET and ECMWF ensemble forecasts drive the tight Polymarket odds clustering around 28°C (26.5%) to 31°C (18.5%) for Sao Paulo's March 25 high temperature, projecting a peak near 28-29°C under a persistent high-pressure ridge suppressing clouds and favoring diurnal heating. Historical airport station data (e.g., GRU) shows March averages of 27.5°C, amplified 1-2°C by urban heat island effects, but sea breeze timing introduces key differentiation—earlier onshore flow could limit peaks to 27°C, while delayed incursions align with GFS warmer biases toward 30°C. Model spread of ±2°C reflects uncertainty in afternoon convective triggers, with final hourly guidance expected to sway trader positions before measurement.
Experimental AI-generated summary referencing Polymarket data · UpdatedHighest temperature in Sao Paulo on March 25?
Highest temperature in Sao Paulo on March 25?
28°C 26%
27°C 21%
29°C 20%
30°C 20%
24°C or below
2%
25°C
5%
26°C
8%
27°C
21%
28°C
26%
29°C
20%
30°C
20%
31°C
19%
32°C
5%
33°C
5%
34°C or higher
5%
28°C 26%
27°C 21%
29°C 20%
30°C 20%
24°C or below
2%
25°C
5%
26°C
8%
27°C
21%
28°C
26%
29°C
20%
30°C
20%
31°C
19%
32°C
5%
33°C
5%
34°C or higher
5%
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: Mar 21, 2026, 6:01 AM ET
Resolution Source
https://www.wunderground.com/history/daily/br/guarulhos/SBGRResolver
0x69c47De9D...Resolution Source
https://www.wunderground.com/history/daily/br/guarulhos/SBGRResolver
0x69c47De9D...Latest INMET and ECMWF ensemble forecasts drive the tight Polymarket odds clustering around 28°C (26.5%) to 31°C (18.5%) for Sao Paulo's March 25 high temperature, projecting a peak near 28-29°C under a persistent high-pressure ridge suppressing clouds and favoring diurnal heating. Historical airport station data (e.g., GRU) shows March averages of 27.5°C, amplified 1-2°C by urban heat island effects, but sea breeze timing introduces key differentiation—earlier onshore flow could limit peaks to 27°C, while delayed incursions align with GFS warmer biases toward 30°C. Model spread of ±2°C reflects uncertainty in afternoon convective triggers, with final hourly guidance expected to sway trader positions before measurement.
Experimental AI-generated summary referencing Polymarket data · Updated
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