Recent National Weather Service and GFS model guidance points to a lowest temperature in Chicago on September 23 in the upper 50s, aligning with the market's leading 58-59°F bin at 44% implied probability. Persistent northeast flow at 5-15 mph under mostly cloudy skies has maintained a modest cooling trend, with recent overnight lows in the mid-to-upper 50s and limited diurnal recovery expected. Historical September climatology places average lows near 55-56°F, but current steering patterns and high pressure favor readings a few degrees above that baseline without significant cold-air advection. Updated model runs and official briefings through the evening of September 22 will refine the exact minimum before market 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 23?
Lowest temperature in Chicago on September 23?
58-59°F 44%
66°F or higher 44%
47°F or below 40%
64-65°F 28%
NEW
NEW
Sep 23, 2026
47°F or below
40%
48-49°F
5%
50-51°F
9%
52-53°F
14%
54-55°F
16%
56-57°F
26%
58-59°F
44%
60-61°F
21%
62-63°F
10%
64-65°F
28%
66°F or higher
44%
58-59°F 44%
66°F or higher 44%
47°F or below 40%
64-65°F 28%
NEW
NEW
Sep 23, 2026
47°F or below
$100 Vol.
40%
48-49°F
$40 Vol.
5%
50-51°F
$49 Vol.
9%
52-53°F
$0 Vol.
14%
54-55°F
$0 Vol.
16%
56-57°F
$0 Vol.
26%
58-59°F
$22 Vol.
44%
60-61°F
$120 Vol.
21%
62-63°F
$120 Vol.
10%
64-65°F
$50 Vol.
28%
66°F or higher
$100 Vol.
44%
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 23 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.Recent National Weather Service and GFS model guidance points to a lowest temperature in Chicago on September 23 in the upper 50s, aligning with the market's leading 58-59°F bin at 44% implied probability. Persistent northeast flow at 5-15 mph under mostly cloudy skies has maintained a modest cooling trend, with recent overnight lows in the mid-to-upper 50s and limited diurnal recovery expected. Historical September climatology places average lows near 55-56°F, but current steering patterns and high pressure favor readings a few degrees above that baseline without significant cold-air advection. Updated model runs and official briefings through the evening of September 22 will refine the exact minimum before market 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 23 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 21, 2026, 3:29 AM ET
Volume
$601End Date
Sep 23, 2026Market Opened
Sep 21, 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 23 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.Recent National Weather Service and GFS model guidance points to a lowest temperature in Chicago on September 23 in the upper 50s, aligning with the market's leading 58-59°F bin at 44% implied probability. Persistent northeast flow at 5-15 mph under mostly cloudy skies has maintained a modest cooling trend, with recent overnight lows in the mid-to-upper 50s and limited diurnal recovery expected. Historical September climatology places average lows near 55-56°F, but current steering patterns and high pressure favor readings a few degrees above that baseline without significant cold-air advection. Updated model runs and official briefings through the evening of September 22 will refine the exact minimum before market 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 23 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
$601End Date
Sep 23, 2026Market Opened
Sep 21, 2026, 3:29 AM ETResolution Source
https://www.weather.gov/wrh/timeseries?site=kordResolver
0x69c47De9D...Recent National Weather Service and GFS model guidance points to a lowest temperature in Chicago on September 23 in the upper 50s, aligning with the market's leading 58-59°F bin at 44% implied probability. Persistent northeast flow at 5-15 mph under mostly cloudy skies has maintained a modest cooling trend, with recent overnight lows in the mid-to-upper 50s and limited diurnal recovery expected. Historical September climatology places average lows near 55-56°F, but current steering patterns and high pressure favor readings a few degrees above that baseline without significant cold-air advection. Updated model runs and official briefings through the evening of September 22 will refine the exact minimum before market 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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