Shanghai in mid-May represents a pivotal seasonal transition from spring into early summer, with daytime highs typically ranging between 20°C and 26°C. This prediction market tests a precisely defined outcome: whether the city's highest temperature on May 19, 2026 will be exactly 21°C—a narrow threshold that requires the day to be cool enough to remain below typical late-spring warming but warm enough not to slip into cooler spring minimums. The current 0% odds reveal strong trader skepticism about this outcome; historical meteorological data shows that exact-temperature matches occur rarely because daily highs naturally fluctuate across broader bands influenced by cloud cover, atmospheric circulation, and regional synoptic patterns. The market resolves based on the official Shanghai Meteorological Service reading, making this a hard-to-predict outcome dependent on jet stream positioning, precipitation patterns, and regional high-pressure system strength in the days immediately preceding May 19. With liquidity of nearly $6,000 and 24-hour volume of $621, the market attracts modest but meaningful participation from weather prediction traders.
What factors could move this market?
Shanghai's climate in late May reflects the transition into the East Asian monsoon season, when the city experiences stronger influence from warm, moist air masses originating over the Pacific Ocean. A high of exactly 21°C would represent a cooler-than-typical May day for Shanghai, positioning the city at the bottom end of normal late-spring conditions and suggesting the persistence of spring-like weather patterns into mid-May. Historical data from the Shanghai Meteorological Service demonstrates that days with highs near 21°C typically occur earlier in the month during cooler spells following rain events that reduce solar heating efficiency. For May 19 to reach exactly 21°C, several meteorological conditions would need to converge: sustained cloud cover limiting daytime heating, a weak or displaced upper-level ridge, and possibly residual moisture from recent precipitation systems. The market's 0% odds reflect trader conviction that Shanghai will be warmer on May 19. This expectation aligns with established climatological patterns showing that 21°C highs become increasingly rare as May progresses toward June, when temperatures typically climb into the 25–27°C range. The precision requirement—exactly 21°C rather than a range—compounds the forecasting difficulty because weather station readings incorporate rounding conventions and may reflect averaging across sub-daily observations. Recent climate trend analysis shows Shanghai's May temperatures have gradually shifted warmer over the past decade, consistent with broader East Asian warming driven by both global circulation changes and regional urbanization effects. The 0% odds suggest traders are highly confident that late-May atmospheric dynamics will push Shanghai toward typical warm conditions rather than anomalously cool outcomes. Volume of $621 in 24 hours reflects the specialized appeal of hyper-granular weather markets, while the $5,979 liquidity pool indicates sufficient depth for meaningful position entry and exit.
What are traders watching for?
May 15–18 upper-level wind patterns and jet stream positioning over East Asia and China
Shanghai Meteorological Service official high reading at 2pm local time on May 19, 2026
Early-to-mid May precipitation and cloud cover frequency across the Yangtze River region
Regional Siberian high-pressure system strength and continental air mass influence patterns
How does this market resolve?
Market resolves YES if Shanghai's official highest temperature on May 19, 2026 is exactly 21°C per the Shanghai Meteorological Service; resolves NO if the high is any other value.
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