Recent National Weather Service forecasts for Chicago on September 20 indicate a high near 68–70°F under mostly cloudy skies, with showers likely, 60% precipitation chances, and breezy northeast winds of 15–25 mph. These conditions follow a frontal passage, suppressing daytime heating below the late-September climatological average of about 74°F. Model runs show minor spread in peak temperatures due to variable cloud cover and timing of showers, keeping outcomes tightly clustered. Trader consensus in the 68–71°F range reflects this forecast uncertainty, with limited upside from stronger mixing or downside from heavier rain. Updated model guidance and NWS briefings ahead of the daily maximum will likely refine the final resolution.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · UpdatedHighest temperature in Chicago on September 20?
Highest temperature in Chicago on September 20?
70-71°F 44%
68-69°F 44%
72-73°F 11%
66-67°F 5%
NEW
NEW
Sep 20, 2026
59°F or below
<1%
60-61°F
<1%
62-63°F
<1%
64-65°F
2%
66-67°F
5%
68-69°F
44%
70-71°F
44%
72-73°F
11%
74-75°F
1%
76-77°F
<1%
78°F or higher
<1%
70-71°F 44%
68-69°F 44%
72-73°F 11%
66-67°F 5%
NEW
NEW
Sep 20, 2026
59°F or below
$111 Vol.
<1%
60-61°F
$111 Vol.
<1%
62-63°F
$187 Vol.
<1%
64-65°F
$42 Vol.
2%
66-67°F
$364 Vol.
5%
68-69°F
$738 Vol.
44%
70-71°F
$705 Vol.
44%
72-73°F
$133 Vol.
11%
74-75°F
$232 Vol.
1%
76-77°F
$112 Vol.
<1%
78°F or higher
$65 Vol.
<1%
This market will resolve to the temperature range that contains the highest temperature recorded by NOAA at the Chicago O'Hare Intl Airport Station in degrees Fahrenheit on 20 Sep '26.
The resolution source for this market will be information from NOAA, specifically the highest 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 forecasts for Chicago on September 20 indicate a high near 68–70°F under mostly cloudy skies, with showers likely, 60% precipitation chances, and breezy northeast winds of 15–25 mph. These conditions follow a frontal passage, suppressing daytime heating below the late-September climatological average of about 74°F. Model runs show minor spread in peak temperatures due to variable cloud cover and timing of showers, keeping outcomes tightly clustered. Trader consensus in the 68–71°F range reflects this forecast uncertainty, with limited upside from stronger mixing or downside from heavier rain. Updated model guidance and NWS briefings ahead of the daily maximum will likely refine the final resolution.
This market will resolve to the temperature range that contains the highest temperature recorded by NOAA at the Chicago O'Hare Intl Airport Station in degrees Fahrenheit on 20 Sep '26.
The resolution source for this market will be information from NOAA, specifically the highest 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 highest 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 18, 2026, 2:56 AM ET
Volume
$2,800End Date
Sep 20, 2026Market Opened
Sep 18, 2026, 2:56 AM ETResolution Source
https://www.weather.gov/wrh/timeseries?site=kordResolver
0x69c47De9D...This market will resolve to the temperature range that contains the highest temperature recorded by NOAA at the Chicago O'Hare Intl Airport Station in degrees Fahrenheit on 20 Sep '26.
The resolution source for this market will be information from NOAA, specifically the highest 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 forecasts for Chicago on September 20 indicate a high near 68–70°F under mostly cloudy skies, with showers likely, 60% precipitation chances, and breezy northeast winds of 15–25 mph. These conditions follow a frontal passage, suppressing daytime heating below the late-September climatological average of about 74°F. Model runs show minor spread in peak temperatures due to variable cloud cover and timing of showers, keeping outcomes tightly clustered. Trader consensus in the 68–71°F range reflects this forecast uncertainty, with limited upside from stronger mixing or downside from heavier rain. Updated model guidance and NWS briefings ahead of the daily maximum will likely refine the final resolution.
This market will resolve to the temperature range that contains the highest temperature recorded by NOAA at the Chicago O'Hare Intl Airport Station in degrees Fahrenheit on 20 Sep '26.
The resolution source for this market will be information from NOAA, specifically the highest 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 highest 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
$2,800End Date
Sep 20, 2026Market Opened
Sep 18, 2026, 2:56 AM ETResolution Source
https://www.weather.gov/wrh/timeseries?site=kordResolver
0x69c47De9D...Recent National Weather Service forecasts for Chicago on September 20 indicate a high near 68–70°F under mostly cloudy skies, with showers likely, 60% precipitation chances, and breezy northeast winds of 15–25 mph. These conditions follow a frontal passage, suppressing daytime heating below the late-September climatological average of about 74°F. Model runs show minor spread in peak temperatures due to variable cloud cover and timing of showers, keeping outcomes tightly clustered. Trader consensus in the 68–71°F range reflects this forecast uncertainty, with limited upside from stronger mixing or downside from heavier rain. Updated model guidance and NWS briefings ahead of the daily maximum will likely refine the final 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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