Official National Weather Service observations from Chicago O'Hare recorded a maximum temperature of 85°F on September 15, 2026—exactly 9°F above the 1991–2020 normal of 76°F—driving the market's 100% implied probability on the 84–85°F bin. This outcome aligned with pre-event model consensus from NOAA guidance, reflecting warmer-than-average conditions under a southerly flow pattern that suppressed typical early-fall cooling. The single-station measurement at O'Hare serves as the authoritative source for resolution, with historical analogs showing September highs in this range occur regularly but rarely exceed 90°F this late in the season. Minor challenges could arise from station-specific microclimate differences or rare post-hoc data revisions, though these remain improbable given the preliminary climate summary's consistency with real-time reports.
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 15?
Highest temperature in Chicago on September 15?
84-85°F 100.0%
71°F or below <1%
72-73°F <1%
74-75°F <1%
$72,419 Vol.
$72,419 Vol.
Sep 15, 2026
71°F or below
<1%
72-73°F
<1%
74-75°F
<1%
76-77°F
<1%
78-79°F
<1%
80-81°F
<1%
82-83°F
<1%
84-85°F
100%
86-87°F
<1%
88-89°F
<1%
90°F or higher
<1%
84-85°F 100.0%
71°F or below <1%
72-73°F <1%
74-75°F <1%
$72,419 Vol.
$72,419 Vol.
Sep 15, 2026
71°F or below
$14,844 Vol.
<1%
72-73°F
$8,564 Vol.
<1%
74-75°F
$7,227 Vol.
<1%
76-77°F
$5,181 Vol.
<1%
78-79°F
$4,305 Vol.
<1%
80-81°F
$5,621 Vol.
<1%
82-83°F
$6,837 Vol.
<1%
84-85°F
$6,803 Vol.
100%
86-87°F
$4,279 Vol.
<1%
88-89°F
$6,347 Vol.
<1%
90°F or higher
$2,410 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 15 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.Official National Weather Service observations from Chicago O'Hare recorded a maximum temperature of 85°F on September 15, 2026—exactly 9°F above the 1991–2020 normal of 76°F—driving the market's 100% implied probability on the 84–85°F bin. This outcome aligned with pre-event model consensus from NOAA guidance, reflecting warmer-than-average conditions under a southerly flow pattern that suppressed typical early-fall cooling. The single-station measurement at O'Hare serves as the authoritative source for resolution, with historical analogs showing September highs in this range occur regularly but rarely exceed 90°F this late in the season. Minor challenges could arise from station-specific microclimate differences or rare post-hoc data revisions, though these remain improbable given the preliminary climate summary's consistency with real-time reports.
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 15 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 13, 2026, 12:56 PM ET
Volume
$72,419End Date
Sep 15, 2026Market Opened
Sep 13, 2026, 12:56 PM 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 15 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.Official National Weather Service observations from Chicago O'Hare recorded a maximum temperature of 85°F on September 15, 2026—exactly 9°F above the 1991–2020 normal of 76°F—driving the market's 100% implied probability on the 84–85°F bin. This outcome aligned with pre-event model consensus from NOAA guidance, reflecting warmer-than-average conditions under a southerly flow pattern that suppressed typical early-fall cooling. The single-station measurement at O'Hare serves as the authoritative source for resolution, with historical analogs showing September highs in this range occur regularly but rarely exceed 90°F this late in the season. Minor challenges could arise from station-specific microclimate differences or rare post-hoc data revisions, though these remain improbable given the preliminary climate summary's consistency with real-time reports.
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 15 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
$72,419End Date
Sep 15, 2026Market Opened
Sep 13, 2026, 12:56 PM ETResolution Source
https://www.weather.gov/wrh/timeseries?site=kordResolver
0x69c47De9D...Official National Weather Service observations from Chicago O'Hare recorded a maximum temperature of 85°F on September 15, 2026—exactly 9°F above the 1991–2020 normal of 76°F—driving the market's 100% implied probability on the 84–85°F bin. This outcome aligned with pre-event model consensus from NOAA guidance, reflecting warmer-than-average conditions under a southerly flow pattern that suppressed typical early-fall cooling. The single-station measurement at O'Hare serves as the authoritative source for resolution, with historical analogs showing September highs in this range occur regularly but rarely exceed 90°F this late in the season. Minor challenges could arise from station-specific microclimate differences or rare post-hoc data revisions, though these remain improbable given the preliminary climate summary's consistency with real-time reports.
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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