TOTAL VOLUME:
$134.2b
24H VOL:
$134,145,987
24H TRANSACTIONS:
2,388,728,490
OPEN INTEREST:
$1,441,166,947
406,422
Markets across
30,383
events
MATCHED EVENTS:
2,688
PLATFORM COVERAGE:
5
Polymarket:
39%
VS.
Kalshi:
61%
Closed: Jun 21, 1:59 AM EST
Kalshi
This event tracks the highest temperature recorded at Chicago Midway, Illinois on June 20, 2026. The resolution uses the official National Weather Service Climatological Report (Daily) as the authoritative source, which may differ from preliminary reports or other weather services.
Resolution is determined by the highest temperature recorded at Chicago Midway, Illinois on June 20, 2026, as reported in the National Weather Service's Climatological Report (Daily). The temperature is divided into six distinct ranges: 77°F or below, 78–79°F, 80–81°F, 82–83°F, 84–85°F, and 86°F or above. Each range corresponds to a separate market outcome that resolves to Yes if the official NWS temperature falls within that range. The official NWS Climatological Report (Daily) is the sole authoritative source for resolution; preliminary NWS data, AccuWeather, Google Weather, and other sources are not used for final determination. Traders should be aware that preliminary NWS reporting and measurement methods may involve rounding and conversion nuances that could affect interpretation of data before the official report is published.
Prediction market odds reflect real-money commitments from traders and often diverge from traditional weather analyst forecasts because markets incorporate a broader range of information and incentivize accuracy through financial stakes. While meteorologists issue deterministic point forecasts or narrow ranges, this market aggregates the beliefs of many participants betting on discrete temperature bands. Analyst forecasts tend to be more conservative and updated less frequently, whereas market odds shift continuously as new data emerges. Over time, prediction markets have demonstrated competitive or superior accuracy compared to single-model forecasts, particularly when the underlying event is observable and verifiable.
On Kalshi, this market is priced through an order-book mechanism where traders buy and sell shares corresponding to specific temperature outcomes. On Kalshi, prices reflect that venue's order book, liquidity, and how traders price the outcome right now. Each outcome contract trades independently, and the price of a share reflects the collective probability assigned by the market. Traders place limit or market orders to enter or exit positions, and the spread between bid and ask prices tightens as liquidity increases. Settlement occurs when the actual high temperature is verified, and winning shares are redeemed at their full contract value while losing shares expire worthless.
This market resolves around Jun 21, 2026, once the highest temperature recorded in Chicago on June 20, 2026 is confirmed and verifiable from credible public sources. The outcome is determined by the official temperature reading from a recognized meteorological authority, ensuring an objective and auditable settlement. Traders holding shares in the outcome bracket that matches the verified high temperature receive their payout, while all other positions expire. The resolution process is final once the data is published and confirmed.
Market prices will shift in response to updated seasonal forecasts, atmospheric patterns, and long-range climate models as June 2026 approaches. Major weather systems, El Niño or La Niña conditions, and anomalies in ocean temperatures can influence trader expectations weeks in advance. Historical heat waves or cold snaps in Chicago during late June may prompt recalibration of probabilities. As the event date nears, short-term weather models become more reliable, typically causing sharper repricing. Media coverage of extreme weather elsewhere or climate trends can also sway sentiment, even if indirect.