National Weather Service forecasts from the Chicago office project a high temperature of 76°F at O'Hare International Airport today under mostly sunny skies with southerly winds enhancing warm air advection, driving the market's 100% implied probability for 54°F or higher. Current observations already show midday readings near 79°F, aligning with model consensus from recent GFS and NAM runs that indicate peak heating this afternoon amid low cloud cover and high pressure dominance. Historical April 21 normals hover around 61°F, making sub-54°F outcomes climatologically improbable without an unforeseen cold front or marine influence, which satellite imagery and upper-air analyses rule out; resolution awaits official daily maximum from NOAA archives.
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 April 21?
Highest temperature in Chicago on April 21?
54°F or higher 100.0%
35°F or below <1%
36-37°F <1%
38-39°F <1%
$143,941 Vol.
$143,941 Vol.
Apr 21, 2026
35°F or below
No
36-37°F
No
38-39°F
No
40-41°F
No
42-43°F
No
44-45°F
No
46-47°F
No
48-49°F
No
50-51°F
No
52-53°F
No
54°F or higher
Yes
54°F or higher 100.0%
35°F or below <1%
36-37°F <1%
38-39°F <1%
$143,941 Vol.
$143,941 Vol.
Apr 21, 2026
35°F or below
$21,200 Vol.
No
36-37°F
$16,038 Vol.
No
38-39°F
$6,632 Vol.
No
40-41°F
$4,743 Vol.
No
42-43°F
$4,098 Vol.
No
44-45°F
$4,070 Vol.
No
46-47°F
$4,121 Vol.
No
48-49°F
$6,627 Vol.
No
50-51°F
$13,973 Vol.
No
52-53°F
$18,983 Vol.
No
54°F or higher
$43,458 Vol.
Yes
This market will resolve to the temperature range that contains the highest temperature recorded at the Chicago O'Hare Intl Airport Station in degrees Fahrenheit on 21 Apr '26.
The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day by the Forecast for the Chicago O'Hare Intl Airport Station once information is finalized, available here: https://www.wunderground.com/history/daily/us/il/chicago/KORD.
To toggle between Fahrenheit and Celsius, click the gear icon next to the search bar and switch the Temperature setting between °F and °C.
This market can not resolve to "Yes" until all data for this date has been finalized.
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.
Any revisions to temperatures recorded after data is finalized for this market's timeframe will not be considered for this market's resolution.National Weather Service forecasts from the Chicago office project a high temperature of 76°F at O'Hare International Airport today under mostly sunny skies with southerly winds enhancing warm air advection, driving the market's 100% implied probability for 54°F or higher. Current observations already show midday readings near 79°F, aligning with model consensus from recent GFS and NAM runs that indicate peak heating this afternoon amid low cloud cover and high pressure dominance. Historical April 21 normals hover around 61°F, making sub-54°F outcomes climatologically improbable without an unforeseen cold front or marine influence, which satellite imagery and upper-air analyses rule out; resolution awaits official daily maximum from NOAA archives.
This market will resolve to the temperature range that contains the highest temperature recorded at the Chicago O'Hare Intl Airport Station in degrees Fahrenheit on 21 Apr '26.
The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day by the Forecast for the Chicago O'Hare Intl Airport Station once information is finalized, available here: https://www.wunderground.com/history/daily/us/il/chicago/KORD.
To toggle between Fahrenheit and Celsius, click the gear icon next to the search bar and switch the Temperature setting between °F and °C.
This market can not resolve to "Yes" until all data for this date has been finalized.
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.
Any revisions to temperatures recorded after data is finalized for this market's timeframe will not be considered for this market's resolution.
The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day by the Forecast for the Chicago O'Hare Intl Airport Station once information is finalized, available here: https://www.wunderground.com/history/daily/us/il/chicago/KORD.
To toggle between Fahrenheit and Celsius, click the gear icon next to the search bar and switch the Temperature setting between °F and °C.
This market can not resolve to "Yes" until all data for this date has been finalized.
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.
Any revisions to temperatures recorded after data is finalized for this market's timeframe will not be considered for this market's resolution.
Market Opened: Apr 19, 2026, 12:06 AM ET
Volume
$143,941End Date
Apr 21, 2026Market Opened
Apr 19, 2026, 12:06 AM ETResolution Source
https://www.wunderground.com/history/daily/us/il/chicago/KORDResolver
0x69c47De9D...Outcome proposed: No
No dispute
Final outcome: No
This market will resolve to the temperature range that contains the highest temperature recorded at the Chicago O'Hare Intl Airport Station in degrees Fahrenheit on 21 Apr '26.
The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day by the Forecast for the Chicago O'Hare Intl Airport Station once information is finalized, available here: https://www.wunderground.com/history/daily/us/il/chicago/KORD.
To toggle between Fahrenheit and Celsius, click the gear icon next to the search bar and switch the Temperature setting between °F and °C.
This market can not resolve to "Yes" until all data for this date has been finalized.
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.
Any revisions to temperatures recorded after data is finalized for this market's timeframe will not be considered for this market's resolution.National Weather Service forecasts from the Chicago office project a high temperature of 76°F at O'Hare International Airport today under mostly sunny skies with southerly winds enhancing warm air advection, driving the market's 100% implied probability for 54°F or higher. Current observations already show midday readings near 79°F, aligning with model consensus from recent GFS and NAM runs that indicate peak heating this afternoon amid low cloud cover and high pressure dominance. Historical April 21 normals hover around 61°F, making sub-54°F outcomes climatologically improbable without an unforeseen cold front or marine influence, which satellite imagery and upper-air analyses rule out; resolution awaits official daily maximum from NOAA archives.
This market will resolve to the temperature range that contains the highest temperature recorded at the Chicago O'Hare Intl Airport Station in degrees Fahrenheit on 21 Apr '26.
The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day by the Forecast for the Chicago O'Hare Intl Airport Station once information is finalized, available here: https://www.wunderground.com/history/daily/us/il/chicago/KORD.
To toggle between Fahrenheit and Celsius, click the gear icon next to the search bar and switch the Temperature setting between °F and °C.
This market can not resolve to "Yes" until all data for this date has been finalized.
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.
Any revisions to temperatures recorded after data is finalized for this market's timeframe will not be considered for this market's resolution.
The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day by the Forecast for the Chicago O'Hare Intl Airport Station once information is finalized, available here: https://www.wunderground.com/history/daily/us/il/chicago/KORD.
To toggle between Fahrenheit and Celsius, click the gear icon next to the search bar and switch the Temperature setting between °F and °C.
This market can not resolve to "Yes" until all data for this date has been finalized.
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.
Any revisions to temperatures recorded after data is finalized for this market's timeframe will not be considered for this market's resolution.
Volume
$143,941End Date
Apr 21, 2026Market Opened
Apr 19, 2026, 12:06 AM ETResolution Source
https://www.wunderground.com/history/daily/us/il/chicago/KORDResolver
0x69c47De9D...Outcome proposed: No
No dispute
Final outcome: No
National Weather Service forecasts from the Chicago office project a high temperature of 76°F at O'Hare International Airport today under mostly sunny skies with southerly winds enhancing warm air advection, driving the market's 100% implied probability for 54°F or higher. Current observations already show midday readings near 79°F, aligning with model consensus from recent GFS and NAM runs that indicate peak heating this afternoon amid low cloud cover and high pressure dominance. Historical April 21 normals hover around 61°F, making sub-54°F outcomes climatologically improbable without an unforeseen cold front or marine influence, which satellite imagery and upper-air analyses rule out; resolution awaits official daily maximum from NOAA archives.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · Updated
Beware of external links.
Beware of external links.
Frequently Asked Questions