Latest National Weather Service and ensemble model guidance point to a daytime high near 79°F in Chicago on May 18, driven by southerly flow ahead of an approaching warm front that supports readings well above the climatological normal of 71°F. Consistent short-range model consensus reinforces this outlook, with a slight risk of severe weather noted by the Storm Prediction Center. These atmospheric conditions underpin the 49% market-implied probability for 78°F or higher, while lower brackets reflect the small chance of a cooler intrusion or forecast revision. Updated guidance over the next 24 hours will further refine the exact maximum ahead of resolution.
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 May 18?
Highest temperature in Chicago on May 18?
78°F or higher 61%
76-77°F 26%
74-75°F 8.5%
72-73°F 1.0%
NEW
$47,445 Vol.
NEW
$47,445 Vol.
May 18, 2026
59°F or below
<1%
60-61°F
<1%
62-63°F
<1%
64-65°F
<1%
66-67°F
<1%
68-69°F
<1%
70-71°F
1%
72-73°F
1%
74-75°F
9%
76-77°F
26%
78°F or higher
61%
78°F or higher 61%
76-77°F 26%
74-75°F 8.5%
72-73°F 1.0%
NEW
$47,445 Vol.
NEW
$47,445 Vol.
May 18, 2026
59°F or below
$26,311 Vol.
<1%
60-61°F
$7,532 Vol.
<1%
62-63°F
$1,143 Vol.
<1%
64-65°F
$1,543 Vol.
<1%
66-67°F
$1,112 Vol.
<1%
68-69°F
$802 Vol.
<1%
70-71°F
$1,114 Vol.
1%
72-73°F
$1,852 Vol.
1%
74-75°F
$1,121 Vol.
9%
76-77°F
$2,254 Vol.
26%
78°F or higher
$2,751 Vol.
61%
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 18 May '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.Latest National Weather Service and ensemble model guidance point to a daytime high near 79°F in Chicago on May 18, driven by southerly flow ahead of an approaching warm front that supports readings well above the climatological normal of 71°F. Consistent short-range model consensus reinforces this outlook, with a slight risk of severe weather noted by the Storm Prediction Center. These atmospheric conditions underpin the 49% market-implied probability for 78°F or higher, while lower brackets reflect the small chance of a cooler intrusion or forecast revision. Updated guidance over the next 24 hours will further refine the exact maximum ahead of resolution.
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 18 May '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: May 16, 2026, 12:04 AM ET
Volume
$47,445End Date
May 18, 2026Market Opened
May 16, 2026, 12:04 AM ETResolution Source
https://www.wunderground.com/history/daily/us/il/chicago/KORDThis 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 18 May '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.Latest National Weather Service and ensemble model guidance point to a daytime high near 79°F in Chicago on May 18, driven by southerly flow ahead of an approaching warm front that supports readings well above the climatological normal of 71°F. Consistent short-range model consensus reinforces this outlook, with a slight risk of severe weather noted by the Storm Prediction Center. These atmospheric conditions underpin the 49% market-implied probability for 78°F or higher, while lower brackets reflect the small chance of a cooler intrusion or forecast revision. Updated guidance over the next 24 hours will further refine the exact maximum ahead of resolution.
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 18 May '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
$47,445End Date
May 18, 2026Market Opened
May 16, 2026, 12:04 AM ETResolution Source
https://www.wunderground.com/history/daily/us/il/chicago/KORDLatest National Weather Service and ensemble model guidance point to a daytime high near 79°F in Chicago on May 18, driven by southerly flow ahead of an approaching warm front that supports readings well above the climatological normal of 71°F. Consistent short-range model consensus reinforces this outlook, with a slight risk of severe weather noted by the Storm Prediction Center. These atmospheric conditions underpin the 49% market-implied probability for 78°F or higher, while lower brackets reflect the small chance of a cooler intrusion or forecast revision. Updated guidance over the next 24 hours will further refine the exact maximum ahead of resolution.
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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