Chicago's weather on May 18 will resolve this extremely narrow temperature band prediction market. The highest temperature must fall between 60-61°F inclusive for a YES resolution, measured against National Weather Service official records. Currently trading at 0% odds, indicating traders collectively view this outcome as highly improbable. Mid-May in Chicago typically features highs in the low-to-mid 70s Fahrenheit, making this 60-61°F target band unusually cool for the season. The market's zero odds reflect the rarity of such mild conditions during late spring. Historical Chicago May temperature data shows highs regularly exceed 70°F by mid-month, with temperatures below 65°F occurring only when unusual cool air masses move through the region. For this market to resolve YES, an unseasonable cold front or upper-level low pressure system would need to dominate Chicago's weather pattern specifically on May 18. The zero-percent odds trajectory suggests no meaningful trader conviction that such conditions will materialize, as longer-term outlooks point toward more typical warm spring conditions taking hold by mid-May.
What factors could move this market?
Chicago's late-spring weather is well-documented in meteorological records and historical temperature databases. The month of May represents Chicago's transition into summer, with average highs climbing steadily from the mid-60s at the start to the low-80s by month's end. May 18 specifically falls near the tail end of spring proper, when Chicago's climate typically settles into warm conditions driven by increasing solar input and frequent high-pressure systems over the eastern United States. For this market to resolve YES, several specific meteorological conditions would need to align. An unusually strong cold front ahead of a deep upper-level trough would be required to suppress temperatures into the 60-61°F range—a phenomenon that occurs perhaps once per decade in late May. This might occur if a significant spring freeze pattern, similar to the anomalous cool snaps that occasionally strike the Midwest in early-to-mid May, extends through May 18. Such conditions typically accompany a northwest wind flow and strong surface high pressure displaced toward Canada. Conversely, the NO scenario—far more probable given current 0% odds—represents normal seasonal progression. By May 18, Chicago typically experiences warm air masses flowing from the south and southwest, with high-pressure ridges building across the Mississippi Valley. Highs in the low-to-mid 70s or potentially reaching 80°F represent the expected outcome for this date. Recent climatological trends also suggest a warming pattern across the Midwest, with spring temperatures increasingly shifting earlier in the season. Historical analogs prove instructive. Unusually cool May days in Chicago are well-recorded but rare in mid-month. The year 1917 saw a notable cold snap through mid-May, and more recently, 2013 experienced cooler-than-normal May conditions, but temperatures remained modestly above the 60-61°F band. Most years show at least one warm day above 75°F by May 18. The current zero-percent odds reflect trader consensus that this outcome carries near-zero probability. The 5,550 USDC liquidity pool at zero percent indicates traders willing to hold YES positions but finding essentially no counterparties. This spread pattern is typical for extreme weather predictions lying far outside climatological norms—the market prices in the statistical rarity of unseasonable cold persisting to mid-May in Chicago.
What are traders watching for?
National Weather Service Chicago forecast issued May 15-17 will signal expected high temperature trajectory; any cold front signal would favor YES.
Upper-level weather models on May 15-16 showing deep trough or cool air mass movement would be key catalyst supporting a narrow 60-61°F outcome.
May 16-17 morning low temperatures; if lows stay below 50°F with northwesterly flow, high temperature suppression becomes more probable.
Actual high temperature reading on May 18 from National Weather Service official Chicago station determines resolution—no weather station variance.
How does this market resolve?
Market resolves YES if Chicago's official high temperature on May 18, 2026 is between 60-61°F inclusive per National Weather Service records; NO otherwise.
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