National Weather Service guidance and ensemble model consensus for July 18 point to daytime highs in the upper 80s to low 90s under a modest ridge with warm-air advection and limited mixing, placing the 88–91 °F bins at the center of trader positioning. This aligns closely with climatological normals near 85 °F while incorporating residual uncertainty from boundary-layer moisture and dew-point trends that could nudge readings a degree or two higher or lower. Recent mid-July warmth, including peaks near 96 °F earlier in the month, has kept the pattern slightly above average without signaling a major heat dome or cold-front passage that would shift probabilities sharply. Updated model runs and any afternoon observations will refine these implied probabilities ahead of market 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 July 18?
88-89°F 40%
90-91°F 29%
86-87°F 14%
92-93°F 12%
81°F or below
<1%
82-83°F
1%
84-85°F
3%
86-87°F
14%
88-89°F
40%
90-91°F
29%
92-93°F
12%
94-95°F
2%
96-97°F
<1%
98-99°F
<1%
100°F or higher
<1%
88-89°F 40%
90-91°F 29%
86-87°F 14%
92-93°F 12%
81°F or below
<1%
82-83°F
1%
84-85°F
3%
86-87°F
14%
88-89°F
40%
90-91°F
29%
92-93°F
12%
94-95°F
2%
96-97°F
<1%
98-99°F
<1%
100°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 for the Chicago O'Hare Intl Airport Station, 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 until the first data point for the following date has been published on the resolution source.
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: Jul 16, 2026, 9:02 PM 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 for the Chicago O'Hare Intl Airport Station, 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 until the first data point for the following date has been published on the resolution source.
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.wunderground.com/history/daily/us/il/chicago/KORDResolver
0x69c47De9D...National Weather Service guidance and ensemble model consensus for July 18 point to daytime highs in the upper 80s to low 90s under a modest ridge with warm-air advection and limited mixing, placing the 88–91 °F bins at the center of trader positioning. This aligns closely with climatological normals near 85 °F while incorporating residual uncertainty from boundary-layer moisture and dew-point trends that could nudge readings a degree or two higher or lower. Recent mid-July warmth, including peaks near 96 °F earlier in the month, has kept the pattern slightly above average without signaling a major heat dome or cold-front passage that would shift probabilities sharply. Updated model runs and any afternoon observations will refine these implied probabilities ahead of market 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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