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icon for Highest temperature in Chicago on August 21?

Highest temperature in Chicago on August 21?

icon for Highest temperature in Chicago on August 21?

Highest temperature in Chicago on August 21?

Aug 20

Aug 21

Aug 20

Aug 21

80-81°F 50%

78-79°F 27%

82-83°F 19%

84-85°F 5%

Polymarket
NEW

80-81°F 50%

78-79°F 27%

82-83°F 19%

84-85°F 5%

Polymarket
NEW

69°F or below

$262 Vol.

<1%

70-71°F

$198 Vol.

<1%

72-73°F

$262 Vol.

<1%

74-75°F

$93 Vol.

1%

76-77°F

$269 Vol.

4%

78-79°F

$303 Vol.

27%

80-81°F

$835 Vol.

50%

82-83°F

$222 Vol.

19%

84-85°F

$275 Vol.

5%

86-87°F

$168 Vol.

3%

88°F or higher

$120 Vol.

<1%

This market will resolve based on the highest temperature recorded in the 'Daily Observations' table on Weather Underground, not the figure displayed in the 'Day High & Low' summary section; in the event of any discrepancy between the two, the Daily Observations table shall be the primary resolution source not the Day High & Low section. 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 Aug '26. 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.Current NWS and AccuWeather forecasts point to a high near 80°F for Chicago on August 21 under mostly sunny conditions, aligning with the market's leading 80-81°F bin at 48.5% implied probability. This outcome reflects a warming trend from recent mid-70s readings as a high-pressure system promotes clearer skies and reduced cloud cover, allowing stronger daytime heating. The projection sits slightly below the 82°F climatological normal, with model consensus narrowing around this range amid typical late-summer variability in Great Lakes air masses. Traders appear to weigh the official guidance heavily while assigning lower odds to 82°F+ outcomes, though minor shifts in steering winds or moisture could adjust the final maximum before resolution.

This market will resolve based on the highest temperature recorded in the 'Daily Observations' table on Weather Underground, not the figure displayed in the 'Day High & Low' summary section; in the event of any discrepancy between the two, the Daily Observations table shall be the primary resolution source not the Day High & Low section.

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 Aug '26.

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.
Volume
$3,007
End Date
Aug 21, 2026
Market Opened
Aug 19, 2026, 9:56 PM ET

Resolution Source

https://www.wunderground.com/history/daily/us/il/chicago/KORD

Resolver

0x69c47De9D...
This market will resolve based on the highest temperature recorded in the 'Daily Observations' table on Weather Underground, not the figure displayed in the 'Day High & Low' summary section; in the event of any discrepancy between the two, the Daily Observations table shall be the primary resolution source not the Day High & Low section. 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 Aug '26. 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.
This market will resolve based on the highest temperature recorded in the 'Daily Observations' table on Weather Underground, not the figure displayed in the 'Day High & Low' summary section; in the event of any discrepancy between the two, the Daily Observations table shall be the primary resolution source not the Day High & Low section. 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 Aug '26. 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.Current NWS and AccuWeather forecasts point to a high near 80°F for Chicago on August 21 under mostly sunny conditions, aligning with the market's leading 80-81°F bin at 48.5% implied probability. This outcome reflects a warming trend from recent mid-70s readings as a high-pressure system promotes clearer skies and reduced cloud cover, allowing stronger daytime heating. The projection sits slightly below the 82°F climatological normal, with model consensus narrowing around this range amid typical late-summer variability in Great Lakes air masses. Traders appear to weigh the official guidance heavily while assigning lower odds to 82°F+ outcomes, though minor shifts in steering winds or moisture could adjust the final maximum before resolution.

This market will resolve based on the highest temperature recorded in the 'Daily Observations' table on Weather Underground, not the figure displayed in the 'Day High & Low' summary section; in the event of any discrepancy between the two, the Daily Observations table shall be the primary resolution source not the Day High & Low section.

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 Aug '26.

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.
Volume
$3,007
End Date
Aug 21, 2026
Market Opened
Aug 19, 2026, 9:56 PM ET

Resolution Source

https://www.wunderground.com/history/daily/us/il/chicago/KORD

Resolver

0x69c47De9D...
This market will resolve based on the highest temperature recorded in the 'Daily Observations' table on Weather Underground, not the figure displayed in the 'Day High & Low' summary section; in the event of any discrepancy between the two, the Daily Observations table shall be the primary resolution source not the Day High & Low section. 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 Aug '26. 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.

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Frequently Asked Questions

"Highest temperature in Chicago on August 21?" is a prediction market on Polymarket with 11 possible outcomes where traders buy and sell shares based on what they believe will happen. The current leading outcome is "80-81°F" at 50%, followed by "78-79°F" at 27%. Prices reflect real-time crowd-sourced probabilities. For example, a share priced at 50¢ implies that the market collectively assigns a 50% chance to that outcome. These odds shift continuously as traders react to new developments and information. Shares in the correct outcome are redeemable for $1 each upon market resolution.

"Highest temperature in Chicago on August 21?" is a newly created market on Polymarket, launched on Aug 19, 2026. As an early market, this is your opportunity to be among the first traders to set the odds and establish the market's initial price signals. You can also bookmark this page to track volume and trading activity as the market gains traction over time.

To trade on "Highest temperature in Chicago on August 21?," browse the 11 available outcomes listed on this page. Each outcome displays a current price representing the market's implied probability. To take a position, select the outcome you believe is most likely, choose "Yes" to trade in favor of it or "No" to trade against it, enter your amount, and click "Trade." If your chosen outcome is correct when the market resolves, your "Yes" shares pay out $1 each. If it's incorrect, they pay out $0. You can also sell your shares at any time before resolution if you want to lock in a profit or cut a loss.

The current frontrunner for "Highest temperature in Chicago on August 21?" is "80-81°F" at 50%, meaning the market assigns a 50% chance to that outcome. The next closest outcome is "78-79°F" at 27%. These odds update in real-time as traders buy and sell shares, so they reflect the latest collective view of what's most likely to happen. Check back frequently or bookmark this page to follow how the odds shift as new information emerges.

The resolution rules for "Highest temperature in Chicago on August 21?" define exactly what needs to happen for each outcome to be declared a winner — including the official data sources used to determine the result. You can review the complete resolution criteria in the "Rules" section on this page above the comments. We recommend reading the rules carefully before trading, as they specify the precise conditions, edge cases, and sources that govern how this market is settled.