Forecast models show a tight spread for Sao Paulo’s maximum temperature on September 25, with 27–28 °C outcomes leading because current GFS and ECMWF runs place the city near the boundary between a weakening subtropical ridge and an approaching frontal system. Daytime heating under partly cloudy skies, combined with the urban heat-island effect, supports readings in the upper 20s, while any earlier-than-expected moisture influx or increased cloud cover could cap the peak at 26 °C. Historical September maxima average near 26–27 °C, so the market-implied odds reflect both climatology and the remaining 48-hour forecast uncertainty. Updated high-resolution runs and INMET guidance expected later today will likely narrow the range before 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 Sao Paulo on September 25?
Highest temperature in Sao Paulo on September 25?
28°C 27%
27°C 26%
26°C 19%
29°C 17%
NEW
NEW
Sep 25, 2026
22°C or below
4%
23°C
4%
24°C
7%
25°C
13%
26°C
19%
27°C
26%
28°C
27%
29°C
17%
30°C
9%
31°C
6%
32°C or higher
2%
28°C 27%
27°C 26%
26°C 19%
29°C 17%
NEW
NEW
Sep 25, 2026
22°C or below
$0 Vol.
4%
23°C
$7 Vol.
4%
24°C
$0 Vol.
7%
25°C
$0 Vol.
13%
26°C
$0 Vol.
19%
27°C
$105 Vol.
26%
28°C
$0 Vol.
27%
29°C
$27 Vol.
17%
30°C
$0 Vol.
9%
31°C
$0 Vol.
6%
32°C or higher
$0 Vol.
2%
This market will resolve to the temperature range that contains the highest temperature recorded by NOAA at the Sao Paulo-Guarulhos International Airport Station in degrees Celsius on 25 Sep '26.
The resolution source for this market will be information from NOAA, specifically the highest reading under the "Temp" column for all times on this day, available here: https://www.weather.gov/wrh/timeseries?site=sbgr
If NOAA data for the observation date is unavailable by 11:59 PM ET on the day following the observation date, the Weather Underground Daily Observations table will be used as the resolution source.
In the event that there is no data for the observation date by 11:59 PM ET on the day following the observation date, this market will resolve to the lowest bracket.
To toggle between Fahrenheit and Celsius, click the "Switch to Metric Units" button until the relevant table displays °C.
This market will resolve once the first data point for the following date has been published on the resolution source, or by 11:59 PM ET on the day following the observation date, whichever comes first.
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.Forecast models show a tight spread for Sao Paulo’s maximum temperature on September 25, with 27–28 °C outcomes leading because current GFS and ECMWF runs place the city near the boundary between a weakening subtropical ridge and an approaching frontal system. Daytime heating under partly cloudy skies, combined with the urban heat-island effect, supports readings in the upper 20s, while any earlier-than-expected moisture influx or increased cloud cover could cap the peak at 26 °C. Historical September maxima average near 26–27 °C, so the market-implied odds reflect both climatology and the remaining 48-hour forecast uncertainty. Updated high-resolution runs and INMET guidance expected later today will likely narrow the range before resolution.
This market will resolve to the temperature range that contains the highest temperature recorded by NOAA at the Sao Paulo-Guarulhos International Airport Station in degrees Celsius on 25 Sep '26.
The resolution source for this market will be information from NOAA, specifically the highest reading under the "Temp" column for all times on this day, available here: https://www.weather.gov/wrh/timeseries?site=sbgr
If NOAA data for the observation date is unavailable by 11:59 PM ET on the day following the observation date, the Weather Underground Daily Observations table will be used as the resolution source.
In the event that there is no data for the observation date by 11:59 PM ET on the day following the observation date, this market will resolve to the lowest bracket.
To toggle between Fahrenheit and Celsius, click the "Switch to Metric Units" button until the relevant table displays °C.
This market will resolve once the first data point for the following date has been published on the resolution source, or by 11:59 PM ET on the day following the observation date, whichever comes first.
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.
The resolution source for this market will be information from NOAA, specifically the highest reading under the "Temp" column for all times on this day, available here: https://www.weather.gov/wrh/timeseries?site=sbgr
If NOAA data for the observation date is unavailable by 11:59 PM ET on the day following the observation date, the Weather Underground Daily Observations table will be used as the resolution source.
In the event that there is no data for the observation date by 11:59 PM ET on the day following the observation date, this market will resolve to the lowest bracket.
To toggle between Fahrenheit and Celsius, click the "Switch to Metric Units" button until the relevant table displays °C.
This market will resolve once the first data point for the following date has been published on the resolution source, or by 11:59 PM ET on the day following the observation date, whichever comes first.
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: Sep 23, 2026, 8:55 AM ET
Volume
$122End Date
Sep 25, 2026Market Opened
Sep 23, 2026, 8:55 AM ETResolution Source
https://www.weather.gov/wrh/timeseries?site=sbgrResolver
0x69c47De9D...This market will resolve to the temperature range that contains the highest temperature recorded by NOAA at the Sao Paulo-Guarulhos International Airport Station in degrees Celsius on 25 Sep '26.
The resolution source for this market will be information from NOAA, specifically the highest reading under the "Temp" column for all times on this day, available here: https://www.weather.gov/wrh/timeseries?site=sbgr
If NOAA data for the observation date is unavailable by 11:59 PM ET on the day following the observation date, the Weather Underground Daily Observations table will be used as the resolution source.
In the event that there is no data for the observation date by 11:59 PM ET on the day following the observation date, this market will resolve to the lowest bracket.
To toggle between Fahrenheit and Celsius, click the "Switch to Metric Units" button until the relevant table displays °C.
This market will resolve once the first data point for the following date has been published on the resolution source, or by 11:59 PM ET on the day following the observation date, whichever comes first.
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.Forecast models show a tight spread for Sao Paulo’s maximum temperature on September 25, with 27–28 °C outcomes leading because current GFS and ECMWF runs place the city near the boundary between a weakening subtropical ridge and an approaching frontal system. Daytime heating under partly cloudy skies, combined with the urban heat-island effect, supports readings in the upper 20s, while any earlier-than-expected moisture influx or increased cloud cover could cap the peak at 26 °C. Historical September maxima average near 26–27 °C, so the market-implied odds reflect both climatology and the remaining 48-hour forecast uncertainty. Updated high-resolution runs and INMET guidance expected later today will likely narrow the range before resolution.
This market will resolve to the temperature range that contains the highest temperature recorded by NOAA at the Sao Paulo-Guarulhos International Airport Station in degrees Celsius on 25 Sep '26.
The resolution source for this market will be information from NOAA, specifically the highest reading under the "Temp" column for all times on this day, available here: https://www.weather.gov/wrh/timeseries?site=sbgr
If NOAA data for the observation date is unavailable by 11:59 PM ET on the day following the observation date, the Weather Underground Daily Observations table will be used as the resolution source.
In the event that there is no data for the observation date by 11:59 PM ET on the day following the observation date, this market will resolve to the lowest bracket.
To toggle between Fahrenheit and Celsius, click the "Switch to Metric Units" button until the relevant table displays °C.
This market will resolve once the first data point for the following date has been published on the resolution source, or by 11:59 PM ET on the day following the observation date, whichever comes first.
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.
The resolution source for this market will be information from NOAA, specifically the highest reading under the "Temp" column for all times on this day, available here: https://www.weather.gov/wrh/timeseries?site=sbgr
If NOAA data for the observation date is unavailable by 11:59 PM ET on the day following the observation date, the Weather Underground Daily Observations table will be used as the resolution source.
In the event that there is no data for the observation date by 11:59 PM ET on the day following the observation date, this market will resolve to the lowest bracket.
To toggle between Fahrenheit and Celsius, click the "Switch to Metric Units" button until the relevant table displays °C.
This market will resolve once the first data point for the following date has been published on the resolution source, or by 11:59 PM ET on the day following the observation date, whichever comes first.
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
$122End Date
Sep 25, 2026Market Opened
Sep 23, 2026, 8:55 AM ETResolution Source
https://www.weather.gov/wrh/timeseries?site=sbgrResolver
0x69c47De9D...Forecast models show a tight spread for Sao Paulo’s maximum temperature on September 25, with 27–28 °C outcomes leading because current GFS and ECMWF runs place the city near the boundary between a weakening subtropical ridge and an approaching frontal system. Daytime heating under partly cloudy skies, combined with the urban heat-island effect, supports readings in the upper 20s, while any earlier-than-expected moisture influx or increased cloud cover could cap the peak at 26 °C. Historical September maxima average near 26–27 °C, so the market-implied odds reflect both climatology and the remaining 48-hour forecast uncertainty. Updated high-resolution runs and INMET guidance expected later today will likely narrow the range before 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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