**Current NWS and private forecasts for Chicago on September 25 project an overnight low in the mid-50s°F (around 55–58°F), consistent with easterly flow off Lake Michigan and recent model runs showing persistent mid-60s highs and mid-50s lows amid mostly cloudy skies.** This places the most likely outcome in the central bins, yet the near-even market odds on the 47°F-or-below and 66°F-or-higher extremes reflect trader focus on remaining forecast uncertainty in steering patterns and potential rapid shifts in the late-September synoptic regime. Lake-effect moderation, wind direction changes, or small timing differences in any weak frontal passage could nudge temperatures toward either tail, while historical September variability (average low near 55°F, record low 33°F) underscores the narrow window for extremes this close to the date. Updated model guidance and official NWS briefings remain the key near-term catalysts.
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 25?
Lowest temperature in Chicago on September 25?
47°F or below 99%
66°F or higher 98%
56-57°F 40%
58-59°F 40%
NEW
NEW
Sep 25, 2026
47°F or below
99%
48-49°F
39%
50-51°F
39%
52-53°F
39%
54-55°F
39%
56-57°F
40%
58-59°F
40%
60-61°F
39%
62-63°F
39%
64-65°F
39%
66°F or higher
98%
47°F or below 99%
66°F or higher 98%
56-57°F 40%
58-59°F 40%
NEW
NEW
Sep 25, 2026
47°F or below
$0 Vol.
99%
48-49°F
$0 Vol.
39%
50-51°F
$0 Vol.
39%
52-53°F
$0 Vol.
39%
54-55°F
$0 Vol.
39%
56-57°F
$0 Vol.
40%
58-59°F
$0 Vol.
40%
60-61°F
$0 Vol.
39%
62-63°F
$0 Vol.
39%
64-65°F
$0 Vol.
39%
66°F or higher
$0 Vol.
98%
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 25 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.**Current NWS and private forecasts for Chicago on September 25 project an overnight low in the mid-50s°F (around 55–58°F), consistent with easterly flow off Lake Michigan and recent model runs showing persistent mid-60s highs and mid-50s lows amid mostly cloudy skies.**
This places the most likely outcome in the central bins, yet the near-even market odds on the 47°F-or-below and 66°F-or-higher extremes reflect trader focus on remaining forecast uncertainty in steering patterns and potential rapid shifts in the late-September synoptic regime. Lake-effect moderation, wind direction changes, or small timing differences in any weak frontal passage could nudge temperatures toward either tail, while historical September variability (average low near 55°F, record low 33°F) underscores the narrow window for extremes this close to the date. Updated model guidance and official NWS briefings remain the key near-term catalysts.
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 25 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 23, 2026, 3:29 AM ET
Volume
$0End Date
Sep 25, 2026Market Opened
Sep 23, 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 25 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.**Current NWS and private forecasts for Chicago on September 25 project an overnight low in the mid-50s°F (around 55–58°F), consistent with easterly flow off Lake Michigan and recent model runs showing persistent mid-60s highs and mid-50s lows amid mostly cloudy skies.**
This places the most likely outcome in the central bins, yet the near-even market odds on the 47°F-or-below and 66°F-or-higher extremes reflect trader focus on remaining forecast uncertainty in steering patterns and potential rapid shifts in the late-September synoptic regime. Lake-effect moderation, wind direction changes, or small timing differences in any weak frontal passage could nudge temperatures toward either tail, while historical September variability (average low near 55°F, record low 33°F) underscores the narrow window for extremes this close to the date. Updated model guidance and official NWS briefings remain the key near-term catalysts.
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 25 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
$0End Date
Sep 25, 2026Market Opened
Sep 23, 2026, 3:29 AM ETResolution Source
https://www.weather.gov/wrh/timeseries?site=kordResolver
0x69c47De9D...**Current NWS and private forecasts for Chicago on September 25 project an overnight low in the mid-50s°F (around 55–58°F), consistent with easterly flow off Lake Michigan and recent model runs showing persistent mid-60s highs and mid-50s lows amid mostly cloudy skies.** This places the most likely outcome in the central bins, yet the near-even market odds on the 47°F-or-below and 66°F-or-higher extremes reflect trader focus on remaining forecast uncertainty in steering patterns and potential rapid shifts in the late-September synoptic regime. Lake-effect moderation, wind direction changes, or small timing differences in any weak frontal passage could nudge temperatures toward either tail, while historical September variability (average low near 55°F, record low 33°F) underscores the narrow window for extremes this close to the date. Updated model guidance and official NWS briefings remain the key near-term catalysts.
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