The National Weather Service's latest forecast pins Chicago's high temperature on March 20 at 70-71°F, aligning with ensemble model outputs from GFS and ECMWF that show consistent mild conditions driven by a ridge of high pressure over the Midwest and southerly winds transporting warmer air from the Gulf. Historical March data supports feasibility, with rare but precedented warm outliers amid a warming climate trend, though baseline averages hover near 45°F. Trader consensus at 100% reflects this convergence, with minimal volatility in recent runs. Realistic challenges include a sudden shift in the jet stream ushering Arctic air or model overestimation of cloud cover, potentially dropping highs to the 60s°F.
Experimental AI-generated summary referencing Polymarket data · UpdatedHighest temperature in Chicago on March 20?
Highest temperature in Chicago on March 20?
70-71°F 100.0%
59°F or below <1%
60-61°F <1%
62-63°F <1%
$264,428 Vol.
$264,428 Vol.
59°F or below
No
60-61°F
No
62-63°F
No
64-65°F
No
66-67°F
No
68-69°F
No
70-71°F
Yes
72-73°F
No
74-75°F
No
76-77°F
No
78°F or higher
No
70-71°F 100.0%
59°F or below <1%
60-61°F <1%
62-63°F <1%
$264,428 Vol.
$264,428 Vol.
59°F or below
No
60-61°F
No
62-63°F
No
64-65°F
No
66-67°F
No
68-69°F
No
70-71°F
Yes
72-73°F
No
74-75°F
No
76-77°F
No
78°F or higher
No
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: Mar 16, 2026, 6:02 AM ET
Resolution Source
https://www.wunderground.com/history/daily/us/il/chicago/KORDResolver
0x69c47De9D...Outcome proposed: No
No dispute
Final outcome: No
Resolution Source
https://www.wunderground.com/history/daily/us/il/chicago/KORDResolver
0x69c47De9D...The National Weather Service's latest forecast pins Chicago's high temperature on March 20 at 70-71°F, aligning with ensemble model outputs from GFS and ECMWF that show consistent mild conditions driven by a ridge of high pressure over the Midwest and southerly winds transporting warmer air from the Gulf. Historical March data supports feasibility, with rare but precedented warm outliers amid a warming climate trend, though baseline averages hover near 45°F. Trader consensus at 100% reflects this convergence, with minimal volatility in recent runs. Realistic challenges include a sudden shift in the jet stream ushering Arctic air or model overestimation of cloud cover, potentially dropping highs to the 60s°F.
Experimental AI-generated summary referencing Polymarket data · Updated
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