Recent polar air advection following a strong cold front has driven unusually low temperatures in São Paulo, with a 10.1°C minimum recorded on September 7—the coldest September reading in four years. Successive cold fronts and a favorable Antarctic Oscillation phase sustain the chill, yet forecasts for the September 9 minimum diverge sharply between models, with some projecting persistent lows near or below 13°C amid heavy cloud cover and rain, while others indicate rapid warming toward 17–20°C as the air mass moderates. This genuine uncertainty between radiative cooling under overcast skies and daytime recovery under clearing conditions explains the near-even market-implied odds for extremes versus mid-range outcomes. Updated INMET and regional model runs over the next 48 hours will likely sharpen resolution.
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?
21°C or higher 69%
11°C or below 64%
17°C 48%
16°C 31%
11°C or below
64%
12°C
24%
13°C
28%
14°C
25%
15°C
27%
16°C
31%
17°C
48%
18°C
26%
19°C
24%
20°C
16%
21°C or higher
69%
21°C or higher 69%
11°C or below 64%
17°C 48%
16°C 31%
11°C or below
64%
12°C
24%
13°C
28%
14°C
25%
15°C
27%
16°C
31%
17°C
48%
18°C
26%
19°C
24%
20°C
16%
21°C or higher
69%
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
Resolution Source
https://www.weather.gov/wrh/timeseries?site=sbgrResolver
0x69c47De9D...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.
Resolution Source
https://www.weather.gov/wrh/timeseries?site=sbgrResolver
0x69c47De9D...Recent polar air advection following a strong cold front has driven unusually low temperatures in São Paulo, with a 10.1°C minimum recorded on September 7—the coldest September reading in four years. Successive cold fronts and a favorable Antarctic Oscillation phase sustain the chill, yet forecasts for the September 9 minimum diverge sharply between models, with some projecting persistent lows near or below 13°C amid heavy cloud cover and rain, while others indicate rapid warming toward 17–20°C as the air mass moderates. This genuine uncertainty between radiative cooling under overcast skies and daytime recovery under clearing conditions explains the near-even market-implied odds for extremes versus mid-range outcomes. Updated INMET and regional model runs over the next 48 hours will likely sharpen 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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