**Trader consensus centers on a 72–75°F peak for Chicago on September 19, reflecting a strong low-pressure system and associated cloud cover and thunderstorms that limit insolation.** Official National Weather Service guidance and model runs indicate a high near 74–76°F under mostly cloudy skies with widespread showers and thunderstorms, especially in the morning and early afternoon, driven by southerly flow ahead of a cold front. Persistent humidity and reduced solar heating from thick cloud decks differentiate the tightly bunched 72–73°F and 74–75°F bins, while historical September 19 averages near 75°F provide context for the modest downside risk priced into 70–71°F. Updated afternoon observations and any clearing trends will be the key near-term variables traders monitor before official daily maximum reports finalize the outcome.
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 19?
Highest temperature in Chicago on September 19?
74-75°F 32%
72-73°F 28%
70-71°F 22%
76-77°F 11%
$26,944 Vol.
$26,944 Vol.
Sep 19, 2026
69°F or below
<1%
70-71°F
22%
72-73°F
28%
74-75°F
32%
76-77°F
11%
78-79°F
6%
80-81°F
1%
82-83°F
1%
84-85°F
<1%
86-87°F
<1%
88°F or higher
<1%
74-75°F 32%
72-73°F 28%
70-71°F 22%
76-77°F 11%
$26,944 Vol.
$26,944 Vol.
Sep 19, 2026
69°F or below
$9,341 Vol.
<1%
70-71°F
$3,986 Vol.
22%
72-73°F
$2,471 Vol.
28%
74-75°F
$2,956 Vol.
32%
76-77°F
$1,314 Vol.
11%
78-79°F
$1,367 Vol.
6%
80-81°F
$3,253 Vol.
1%
82-83°F
$1,395 Vol.
1%
84-85°F
$639 Vol.
<1%
86-87°F
$111 Vol.
<1%
88°F or higher
$111 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 19 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.**Trader consensus centers on a 72–75°F peak for Chicago on September 19, reflecting a strong low-pressure system and associated cloud cover and thunderstorms that limit insolation.** Official National Weather Service guidance and model runs indicate a high near 74–76°F under mostly cloudy skies with widespread showers and thunderstorms, especially in the morning and early afternoon, driven by southerly flow ahead of a cold front. Persistent humidity and reduced solar heating from thick cloud decks differentiate the tightly bunched 72–73°F and 74–75°F bins, while historical September 19 averages near 75°F provide context for the modest downside risk priced into 70–71°F. Updated afternoon observations and any clearing trends will be the key near-term variables traders monitor before official daily maximum reports finalize the outcome.
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 19 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 17, 2026, 2:56 AM ET
Volume
$26,944End Date
Sep 19, 2026Market Opened
Sep 17, 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 19 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.**Trader consensus centers on a 72–75°F peak for Chicago on September 19, reflecting a strong low-pressure system and associated cloud cover and thunderstorms that limit insolation.** Official National Weather Service guidance and model runs indicate a high near 74–76°F under mostly cloudy skies with widespread showers and thunderstorms, especially in the morning and early afternoon, driven by southerly flow ahead of a cold front. Persistent humidity and reduced solar heating from thick cloud decks differentiate the tightly bunched 72–73°F and 74–75°F bins, while historical September 19 averages near 75°F provide context for the modest downside risk priced into 70–71°F. Updated afternoon observations and any clearing trends will be the key near-term variables traders monitor before official daily maximum reports finalize the outcome.
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 19 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
$26,944End Date
Sep 19, 2026Market Opened
Sep 17, 2026, 2:56 AM ETResolution Source
https://www.weather.gov/wrh/timeseries?site=kordResolver
0x69c47De9D...**Trader consensus centers on a 72–75°F peak for Chicago on September 19, reflecting a strong low-pressure system and associated cloud cover and thunderstorms that limit insolation.** Official National Weather Service guidance and model runs indicate a high near 74–76°F under mostly cloudy skies with widespread showers and thunderstorms, especially in the morning and early afternoon, driven by southerly flow ahead of a cold front. Persistent humidity and reduced solar heating from thick cloud decks differentiate the tightly bunched 72–73°F and 74–75°F bins, while historical September 19 averages near 75°F provide context for the modest downside risk priced into 70–71°F. Updated afternoon observations and any clearing trends will be the key near-term variables traders monitor before official daily maximum reports finalize the outcome.
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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Frequently Asked Questions