Recent anomalous rainfall across São Paulo, already the wettest September since 1943 with over 250 mm recorded by mid-month, has sustained extensive cloud cover and advected cooler maritime air, suppressing daytime heating and elevating overnight lows relative to climatology. Official forecasts from INMET-aligned models and ensemble guidance project a September 18 minimum near 11–15 °C under continued easterly flow and high humidity, placing the outcome near historical September averages while leaving room for modest deviations from model spread or localized radiative cooling under clearing skies. Traders therefore assign nearly equal weight to sub-10 °C and 19 °C+ extremes, reflecting genuine uncertainty in how quickly the current moisture-laden pattern erodes ahead of the 48-hour window.
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 18?
Lowest temperature in Sao Paulo on September 18?
9°C or below 94%
19°C or higher 93%
13°C 40%
10°C 38%
NEW
NEW
Sep 18, 2026
9°C or below
94%
10°C
38%
11°C
38%
12°C
38%
13°C
40%
14°C
25%
15°C
20%
16°C
38%
17°C
38%
18°C
38%
19°C or higher
93%
9°C or below 94%
19°C or higher 93%
13°C 40%
10°C 38%
NEW
NEW
Sep 18, 2026
9°C or below
$0 Vol.
94%
10°C
$0 Vol.
38%
11°C
$0 Vol.
38%
12°C
$0 Vol.
38%
13°C
$0 Vol.
40%
14°C
$0 Vol.
25%
15°C
$0 Vol.
20%
16°C
$0 Vol.
38%
17°C
$0 Vol.
38%
18°C
$0 Vol.
38%
19°C or higher
$0 Vol.
93%
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 18 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 anomalous rainfall across São Paulo, already the wettest September since 1943 with over 250 mm recorded by mid-month, has sustained extensive cloud cover and advected cooler maritime air, suppressing daytime heating and elevating overnight lows relative to climatology. Official forecasts from INMET-aligned models and ensemble guidance project a September 18 minimum near 11–15 °C under continued easterly flow and high humidity, placing the outcome near historical September averages while leaving room for modest deviations from model spread or localized radiative cooling under clearing skies. Traders therefore assign nearly equal weight to sub-10 °C and 19 °C+ extremes, reflecting genuine uncertainty in how quickly the current moisture-laden pattern erodes ahead of the 48-hour window.
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 18 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 16, 2026, 8:28 AM ET
Volume
$0End Date
Sep 18, 2026Market Opened
Sep 16, 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 18 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 anomalous rainfall across São Paulo, already the wettest September since 1943 with over 250 mm recorded by mid-month, has sustained extensive cloud cover and advected cooler maritime air, suppressing daytime heating and elevating overnight lows relative to climatology. Official forecasts from INMET-aligned models and ensemble guidance project a September 18 minimum near 11–15 °C under continued easterly flow and high humidity, placing the outcome near historical September averages while leaving room for modest deviations from model spread or localized radiative cooling under clearing skies. Traders therefore assign nearly equal weight to sub-10 °C and 19 °C+ extremes, reflecting genuine uncertainty in how quickly the current moisture-laden pattern erodes ahead of the 48-hour window.
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 18 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 18, 2026Market Opened
Sep 16, 2026, 8:28 AM ETResolution Source
https://www.weather.gov/wrh/timeseries?site=sbgrResolver
0x69c47De9D...Recent anomalous rainfall across São Paulo, already the wettest September since 1943 with over 250 mm recorded by mid-month, has sustained extensive cloud cover and advected cooler maritime air, suppressing daytime heating and elevating overnight lows relative to climatology. Official forecasts from INMET-aligned models and ensemble guidance project a September 18 minimum near 11–15 °C under continued easterly flow and high humidity, placing the outcome near historical September averages while leaving room for modest deviations from model spread or localized radiative cooling under clearing skies. Traders therefore assign nearly equal weight to sub-10 °C and 19 °C+ extremes, reflecting genuine uncertainty in how quickly the current moisture-laden pattern erodes ahead of the 48-hour window.
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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