Trader consensus on Polymarket heavily favors a high temperature of 55°F or below at Chicago's O'Hare International Airport on April 20 (67% implied probability), driven by the latest National Weather Service forecasts and GFS/ECMWF ensemble consensus projecting a daytime maximum near 50-52°F. This positioning stems from a recent cold frontal passage on April 17-18, which swept away a steamy stretch with highs near 82°F earlier in the week, ushering in a deep upper-level trough and crisp Canadian air mass. Persistent northwest winds of 15-20 mph will further suppress temperatures below seasonal normals of 61°F, with partly sunny skies limiting solar warming. New 12Z model runs and NWS updates expected today could refine this outlook amid typical spring forecast uncertainty.
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 20?
Highest temperature in Chicago on April 20?
55°F or below 69%
56-57°F 22%
58-59°F 3.9%
60-61°F 2.6%
55°F or below
69%
56-57°F
22%
58-59°F
4%
60-61°F
3%
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°F or higher
1%
55°F or below 69%
56-57°F 22%
58-59°F 3.9%
60-61°F 2.6%
55°F or below
69%
56-57°F
22%
58-59°F
4%
60-61°F
3%
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°F or higher
1%
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 18, 2026, 12:40 AM ET
Resolution Source
https://www.wunderground.com/history/daily/us/il/chicago/KORDResolver
0x69c47De9D...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.
Resolution Source
https://www.wunderground.com/history/daily/us/il/chicago/KORDResolver
0x69c47De9D...Trader consensus on Polymarket heavily favors a high temperature of 55°F or below at Chicago's O'Hare International Airport on April 20 (67% implied probability), driven by the latest National Weather Service forecasts and GFS/ECMWF ensemble consensus projecting a daytime maximum near 50-52°F. This positioning stems from a recent cold frontal passage on April 17-18, which swept away a steamy stretch with highs near 82°F earlier in the week, ushering in a deep upper-level trough and crisp Canadian air mass. Persistent northwest winds of 15-20 mph will further suppress temperatures below seasonal normals of 61°F, with partly sunny skies limiting solar warming. New 12Z model runs and NWS updates expected today could refine this outlook amid typical spring forecast uncertainty.
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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