Current forecasts from the National Weather Service and supporting models indicate a low around 65–67°F for Chicago on September 18, driven by persistent northeast flow, high humidity, and cloud cover that restricts overnight radiative cooling. This setup aligns with typical late-summer patterns but leaves room for variance depending on the exact timing of any showers or breaks in cloudiness, which could allow temperatures to dip closer to seasonal normals near 58°F or remain elevated. The near-even market split between the 57°F-or-below and 76°F-or-higher outcomes reflects trader emphasis on these boundary uncertainties in model runs, while the clustered mid-range probabilities capture the baseline consensus around observed guidance. Updated model outputs and evening observations over the next 48 hours will likely refine the precise minimum before 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 Chicago on September 18?
Lowest temperature in Chicago on September 18?
66-67°F 40%
68-69°F 40%
64-65°F 39%
62-63°F 19%
NEW
NEW
Sep 18, 2026
57°F or below
5%
58-59°F
7%
60-61°F
11%
62-63°F
19%
64-65°F
39%
66-67°F
40%
68-69°F
40%
70-71°F
19%
72-73°F
11%
74-75°F
7%
76°F or higher
5%
66-67°F 40%
68-69°F 40%
64-65°F 39%
62-63°F 19%
NEW
NEW
Sep 18, 2026
57°F or below
$0 Vol.
5%
58-59°F
$0 Vol.
7%
60-61°F
$0 Vol.
11%
62-63°F
$0 Vol.
19%
64-65°F
$0 Vol.
39%
66-67°F
$0 Vol.
40%
68-69°F
$0 Vol.
40%
70-71°F
$0 Vol.
19%
72-73°F
$0 Vol.
11%
74-75°F
$0 Vol.
7%
76°F or higher
$0 Vol.
5%
This market will resolve to the temperature range that contains the lowest temperature recorded by NOAA at the Chicago O'Hare Intl Airport Station in degrees Fahrenheit 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=kord
This market will resolve off of the Hourly Data provided using the "Show Hourly Data" button.
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 US Units w/ kts" button until the relevant table displays °F.
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 Fahrenheit (eg, 21°F). 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.Current forecasts from the National Weather Service and supporting models indicate a low around 65–67°F for Chicago on September 18, driven by persistent northeast flow, high humidity, and cloud cover that restricts overnight radiative cooling. This setup aligns with typical late-summer patterns but leaves room for variance depending on the exact timing of any showers or breaks in cloudiness, which could allow temperatures to dip closer to seasonal normals near 58°F or remain elevated. The near-even market split between the 57°F-or-below and 76°F-or-higher outcomes reflects trader emphasis on these boundary uncertainties in model runs, while the clustered mid-range probabilities capture the baseline consensus around observed guidance. Updated model outputs and evening observations over the next 48 hours will likely refine the precise minimum before resolution.
This market will resolve to the temperature range that contains the lowest temperature recorded by NOAA at the Chicago O'Hare Intl Airport Station in degrees Fahrenheit 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=kord
This market will resolve off of the Hourly Data provided using the "Show Hourly Data" button.
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 US Units w/ kts" button until the relevant table displays °F.
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 Fahrenheit (eg, 21°F). 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=kord
This market will resolve off of the Hourly Data provided using the "Show Hourly Data" button.
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 US Units w/ kts" button until the relevant table displays °F.
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 Fahrenheit (eg, 21°F). 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, 3:29 AM ET
Volume
$0End Date
Sep 18, 2026Market Opened
Sep 16, 2026, 3:29 AM ETResolution Source
https://www.weather.gov/wrh/timeseries?site=kordResolver
0x69c47De9D...This market will resolve to the temperature range that contains the lowest temperature recorded by NOAA at the Chicago O'Hare Intl Airport Station in degrees Fahrenheit 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=kord
This market will resolve off of the Hourly Data provided using the "Show Hourly Data" button.
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 US Units w/ kts" button until the relevant table displays °F.
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 Fahrenheit (eg, 21°F). 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.Current forecasts from the National Weather Service and supporting models indicate a low around 65–67°F for Chicago on September 18, driven by persistent northeast flow, high humidity, and cloud cover that restricts overnight radiative cooling. This setup aligns with typical late-summer patterns but leaves room for variance depending on the exact timing of any showers or breaks in cloudiness, which could allow temperatures to dip closer to seasonal normals near 58°F or remain elevated. The near-even market split between the 57°F-or-below and 76°F-or-higher outcomes reflects trader emphasis on these boundary uncertainties in model runs, while the clustered mid-range probabilities capture the baseline consensus around observed guidance. Updated model outputs and evening observations over the next 48 hours will likely refine the precise minimum before resolution.
This market will resolve to the temperature range that contains the lowest temperature recorded by NOAA at the Chicago O'Hare Intl Airport Station in degrees Fahrenheit 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=kord
This market will resolve off of the Hourly Data provided using the "Show Hourly Data" button.
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 US Units w/ kts" button until the relevant table displays °F.
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 Fahrenheit (eg, 21°F). 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=kord
This market will resolve off of the Hourly Data provided using the "Show Hourly Data" button.
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 US Units w/ kts" button until the relevant table displays °F.
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 Fahrenheit (eg, 21°F). 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, 3:29 AM ETResolution Source
https://www.weather.gov/wrh/timeseries?site=kordResolver
0x69c47De9D...Current forecasts from the National Weather Service and supporting models indicate a low around 65–67°F for Chicago on September 18, driven by persistent northeast flow, high humidity, and cloud cover that restricts overnight radiative cooling. This setup aligns with typical late-summer patterns but leaves room for variance depending on the exact timing of any showers or breaks in cloudiness, which could allow temperatures to dip closer to seasonal normals near 58°F or remain elevated. The near-even market split between the 57°F-or-below and 76°F-or-higher outcomes reflects trader emphasis on these boundary uncertainties in model runs, while the clustered mid-range probabilities capture the baseline consensus around observed guidance. Updated model outputs and evening observations over the next 48 hours will likely refine the precise minimum 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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