Recent National Weather Service forecasts and model consensus indicate overnight lows in Chicago on September 17 will likely settle in the mid-to-upper 60s under mostly cloudy skies with light northerly to northeasterly flow. Persistent high humidity and a lack of strong cold advection have kept temperatures elevated relative to the long-term September average low near 58°F. These conditions support the market's leading 66-67°F bin at 48% implied probability while leaving room for the 37% chance assigned to 59°F or below if a sharper cool-down develops. Updated model runs and any shifts in steering patterns ahead of resolution will be key near-term catalysts for price movement.
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 17?
59°F or below 68%
66-67°F 48%
70-71°F 39%
64-65°F 38%
59°F or below
68%
60-61°F
9%
62-63°F
14%
64-65°F
23%
66-67°F
48%
68-69°F
25%
70-71°F
39%
72-73°F
9%
74-75°F
4%
76-77°F
1%
78°F or higher
1%
59°F or below 68%
66-67°F 48%
70-71°F 39%
64-65°F 38%
59°F or below
68%
60-61°F
9%
62-63°F
14%
64-65°F
23%
66-67°F
48%
68-69°F
25%
70-71°F
39%
72-73°F
9%
74-75°F
4%
76-77°F
1%
78°F or higher
1%
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 15, 2026, 3:29 AM ET
Resolution Source
https://www.weather.gov/wrh/timeseries?site=kordResolver
0x69c47De9D...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.
Resolution Source
https://www.weather.gov/wrh/timeseries?site=kordResolver
0x69c47De9D...Recent National Weather Service forecasts and model consensus indicate overnight lows in Chicago on September 17 will likely settle in the mid-to-upper 60s under mostly cloudy skies with light northerly to northeasterly flow. Persistent high humidity and a lack of strong cold advection have kept temperatures elevated relative to the long-term September average low near 58°F. These conditions support the market's leading 66-67°F bin at 48% implied probability while leaving room for the 37% chance assigned to 59°F or below if a sharper cool-down develops. Updated model runs and any shifts in steering patterns ahead of resolution will be key near-term catalysts for price movement.
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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