Chicago's typical high temperature in early May ranges from 62-68°F, making a narrow band of 38-39°F exceptionally cold for the season. Such a reading would represent a significant late-season frost event, roughly 25 degrees below the historical norm for this time of year. The 0% current odds reflect trader conviction that this scenario is virtually impossible given present weather patterns and the approach of warm spring days. A high of 38-39°F would require a dramatic Arctic outflow or severe weather system to stall over the Midwest, an unlikely occurrence in May when warmer air masses typically dominate the continental pattern. The market's strong lean toward NO suggests the trader consensus: late spring temperature swings this severe rarely materialize, and Chicago is past the window for such dramatic cold snaps. Weather records show that Chicago recorded a 37°F high only once in May over the past 50 years, highlighting the exceptional rarity of such conditions. Current weather models show no extreme cold system tracking toward the region through May 2, and seasonal norms strongly favor near or above-normal temperatures for early May across the northern Midwest.
Deep dive — what moves this market
Chicago's climate data shows that by May 2, the city typically experiences warming trends as spring consolidates across the northern Midwest. Historical records from the National Weather Service Chicago office document that average high temperatures in early May range from 62 to 68 degrees Fahrenheit, with normal lows around 48-50°F. A high temperature of only 38-39°F would represent a dramatic departure from climatological norms—roughly 25 degrees below the seasonal average. Such an outcome would constitute a notable late-season frost event, requiring an unusual convergence of atmospheric conditions. For Chicago to see such a cold high, a strong cold front accompanied by Arctic air would need to move through the region, combined with clear skies and light winds that allow temperatures to plummet overnight and struggle to recover during daylight hours. This specific combination becomes increasingly rare as May progresses and the jet stream shifts northward, allowing warmer subtropical air to establish over the central United States. Historical analysis shows that truly severe cold snaps after April are uncommon in the Chicago area, with May's average minimum temperatures rarely dropping below the mid-30s Fahrenheit range in recent decades. Recent spring weather patterns across North America have shown increasing warmth overall, with earlier growing seasons and reduced frequency of late-season cold events compared to the mid-20th century baseline. The broader climate context suggests that atmospheric blocking patterns capable of steering Arctic air southward become progressively weaker as May begins, with the energy source for such systems diminishing as solar angles increase. Traders pricing this market at 0% odds are effectively betting that modern weather patterns and seasonal dynamics make this specific temperature band a near-zero-probability outcome. The strength of this consensus reflects confidence that May's climatic transition has advanced sufficiently to preclude such dramatic reversions to winter-like conditions. Current medium-range weather models show no significant cold system tracking toward the Midwest through May 2, with guidance generally favoring near or above-normal temperatures. The market's assessment appears well-grounded in both historical climatology and real-time meteorological data, supported by the current atmospheric setup and seasonal norms.
What traders watch for
Official Chicago NWS station high temperature for May 2; resolves exactly at midnight CT as market expires
Extended forecast models through May 2; watch for any surprise Arctic outbreak (extremely unlikely given spring patterns)
Overnight low temperatures May 1-2 as indicator; frost events would suggest atmospheric conditions favoring narrow outcome
Jet stream monitoring; northward positioning reduces Arctic air transport capacity required for 38-39°F high
How does this market resolve?
Market resolves on May 3 based on the official National Weather Service Chicago office's reported high temperature for May 2, 2026, with YES winning if the high falls between 38-39°F inclusive.
Prediction markets aggregate trader expectations into real-time probability estimates. On Polymarket Trade, every market question resolves YES or NO based on a specific event outcome; traders buy shares of the side they believe will resolve positively. Prices range 0¢ (certain no) to 100¢ (certain yes) and naturally reflect the crowd-implied probability of YES. This page summarizes the market state for readers arriving from search; for live trading (place orders, see order book depth, execute a trade) open the full interactive page linked above.
