Current National Weather Service forecasts for Chicago on September 18 project a high near 74°F under mostly cloudy skies with a slight afternoon shower chance, driven by persistent northeasterly flow and modest moisture that limits daytime heating. Ensemble model consensus from recent runs supports this range, consistent with mid-September climatology where highs average near 75°F but often moderate under similar synoptic patterns. Trader positioning around 74-75°F and 70-71°F reflects this guidance, while the 22% implied probability on 82°F or higher accounts for uncertainty if clearing occurs earlier than expected or if model bias underestimates mixing. Updated NWS briefings and next model cycles will refine the exact maximum before 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 18?
Highest temperature in Chicago on September 18?
82°F or higher 44%
74-75°F 39%
72-73°F 36%
76-77°F 29%
NEW
NEW
Sep 18, 2026
63°F or below
6%
64-65°F
7%
66-67°F
8%
68-69°F
17%
70-71°F
27%
72-73°F
36%
74-75°F
33%
76-77°F
29%
78-79°F
18%
80-81°F
16%
82°F or higher
44%
82°F or higher 44%
74-75°F 39%
72-73°F 36%
76-77°F 29%
NEW
NEW
Sep 18, 2026
63°F or below
$0 Vol.
6%
64-65°F
$0 Vol.
7%
66-67°F
$0 Vol.
8%
68-69°F
$0 Vol.
17%
70-71°F
$354 Vol.
27%
72-73°F
$0 Vol.
36%
74-75°F
$26 Vol.
33%
76-77°F
$0 Vol.
29%
78-79°F
$0 Vol.
18%
80-81°F
$0 Vol.
16%
82°F or higher
$0 Vol.
44%
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 18 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.Current National Weather Service forecasts for Chicago on September 18 project a high near 74°F under mostly cloudy skies with a slight afternoon shower chance, driven by persistent northeasterly flow and modest moisture that limits daytime heating. Ensemble model consensus from recent runs supports this range, consistent with mid-September climatology where highs average near 75°F but often moderate under similar synoptic patterns. Trader positioning around 74-75°F and 70-71°F reflects this guidance, while the 22% implied probability on 82°F or higher accounts for uncertainty if clearing occurs earlier than expected or if model bias underestimates mixing. Updated NWS briefings and next model cycles will refine the exact maximum before 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 18 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 16, 2026, 3:56 AM ET
Volume
$379End Date
Sep 18, 2026Market Opened
Sep 16, 2026, 3:56 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 18 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.Current National Weather Service forecasts for Chicago on September 18 project a high near 74°F under mostly cloudy skies with a slight afternoon shower chance, driven by persistent northeasterly flow and modest moisture that limits daytime heating. Ensemble model consensus from recent runs supports this range, consistent with mid-September climatology where highs average near 75°F but often moderate under similar synoptic patterns. Trader positioning around 74-75°F and 70-71°F reflects this guidance, while the 22% implied probability on 82°F or higher accounts for uncertainty if clearing occurs earlier than expected or if model bias underestimates mixing. Updated NWS briefings and next model cycles will refine the exact maximum before 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 18 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
$379End Date
Sep 18, 2026Market Opened
Sep 16, 2026, 3:56 AM ETResolution Source
https://www.weather.gov/wrh/timeseries?site=kordResolver
0x69c47De9D...Current National Weather Service forecasts for Chicago on September 18 project a high near 74°F under mostly cloudy skies with a slight afternoon shower chance, driven by persistent northeasterly flow and modest moisture that limits daytime heating. Ensemble model consensus from recent runs supports this range, consistent with mid-September climatology where highs average near 75°F but often moderate under similar synoptic patterns. Trader positioning around 74-75°F and 70-71°F reflects this guidance, while the 22% implied probability on 82°F or higher accounts for uncertainty if clearing occurs earlier than expected or if model bias underestimates mixing. Updated NWS briefings and next model cycles will refine the exact maximum 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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