Recent polar air mass advection has driven unusually low overnight minima across São Paulo, with an official 10.1°C reading on September 7 marking the coldest September dawn in four years. Numerical guidance for the September 9 minimum shows a tight spread centered near 13–17°C under persistent cloud cover, light easterly flow, and scattered showers that limit radiational cooling. Ensemble members diverge mainly on the timing and strength of any residual cold-air drainage versus gradual moderation from increasing northerly winds and higher dew points. This scientific uncertainty—centered on boundary-layer mixing and precipitation efficiency—explains the near-even market-implied odds between sub-12°C extremes and values above 20°C.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · UpdatedLowest temperature in Sao Paulo on September 9?
Lowest temperature in Sao Paulo on September 9?
21°C or higher 88%
11°C or below 84%
17°C 49%
12°C 42%
NEW
NEW
Sep 9, 2026
11°C or below
84%
12°C
42%
13°C
42%
14°C
26%
15°C
27%
16°C
29%
17°C
49%
18°C
42%
19°C
42%
20°C
16%
21°C or higher
88%
21°C or higher 88%
11°C or below 84%
17°C 49%
12°C 42%
NEW
NEW
Sep 9, 2026
11°C or below
$0 Vol.
84%
12°C
$0 Vol.
42%
13°C
$0 Vol.
42%
14°C
$0 Vol.
26%
15°C
$0 Vol.
27%
16°C
$0 Vol.
29%
17°C
$0 Vol.
49%
18°C
$0 Vol.
42%
19°C
$0 Vol.
42%
20°C
$0 Vol.
16%
21°C or higher
$0 Vol.
88%
This market will resolve to the temperature range that contains the lowest temperature recorded by NOAA at the Sao Paulo-Guarulhos International Airport Station in degrees Celsius on 9 Sep '26.
The resolution source for this market will be information from NOAA, specifically the lowest 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.Recent polar air mass advection has driven unusually low overnight minima across São Paulo, with an official 10.1°C reading on September 7 marking the coldest September dawn in four years. Numerical guidance for the September 9 minimum shows a tight spread centered near 13–17°C under persistent cloud cover, light easterly flow, and scattered showers that limit radiational cooling. Ensemble members diverge mainly on the timing and strength of any residual cold-air drainage versus gradual moderation from increasing northerly winds and higher dew points. This scientific uncertainty—centered on boundary-layer mixing and precipitation efficiency—explains the near-even market-implied odds between sub-12°C extremes and values above 20°C.
This market will resolve to the temperature range that contains the lowest temperature recorded by NOAA at the Sao Paulo-Guarulhos International Airport Station in degrees Celsius on 9 Sep '26.
The resolution source for this market will be information from NOAA, specifically the lowest 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 lowest 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 7, 2026, 8:28 AM ET
Volume
$0End Date
Sep 9, 2026Market Opened
Sep 7, 2026, 8:28 AM ETResolution Source
https://www.weather.gov/wrh/timeseries?site=sbgrResolver
0x69c47De9D...This market will resolve to the temperature range that contains the lowest temperature recorded by NOAA at the Sao Paulo-Guarulhos International Airport Station in degrees Celsius on 9 Sep '26.
The resolution source for this market will be information from NOAA, specifically the lowest 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.Recent polar air mass advection has driven unusually low overnight minima across São Paulo, with an official 10.1°C reading on September 7 marking the coldest September dawn in four years. Numerical guidance for the September 9 minimum shows a tight spread centered near 13–17°C under persistent cloud cover, light easterly flow, and scattered showers that limit radiational cooling. Ensemble members diverge mainly on the timing and strength of any residual cold-air drainage versus gradual moderation from increasing northerly winds and higher dew points. This scientific uncertainty—centered on boundary-layer mixing and precipitation efficiency—explains the near-even market-implied odds between sub-12°C extremes and values above 20°C.
This market will resolve to the temperature range that contains the lowest temperature recorded by NOAA at the Sao Paulo-Guarulhos International Airport Station in degrees Celsius on 9 Sep '26.
The resolution source for this market will be information from NOAA, specifically the lowest 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 lowest 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
$0End Date
Sep 9, 2026Market Opened
Sep 7, 2026, 8:28 AM ETResolution Source
https://www.weather.gov/wrh/timeseries?site=sbgrResolver
0x69c47De9D...Recent polar air mass advection has driven unusually low overnight minima across São Paulo, with an official 10.1°C reading on September 7 marking the coldest September dawn in four years. Numerical guidance for the September 9 minimum shows a tight spread centered near 13–17°C under persistent cloud cover, light easterly flow, and scattered showers that limit radiational cooling. Ensemble members diverge mainly on the timing and strength of any residual cold-air drainage versus gradual moderation from increasing northerly winds and higher dew points. This scientific uncertainty—centered on boundary-layer mixing and precipitation efficiency—explains the near-even market-implied odds between sub-12°C extremes and values above 20°C.
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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