Shanghai enters its warm season in mid-May, with daily highs typically ranging from 24 to 28 degrees Celsius. A maximum temperature of 21°C or below would represent a notably cool day for this period in the seasonal calendar. The 0% YES odds visible in this market reflect trader consensus that Shanghai will exceed this temperature threshold on May 17, 2026. Late spring weather patterns throughout eastern China are dominated by steady warming trends as Shanghai transitions from spring into early summer. Historical climate data shows that days with highs of 21°C or below are statistically rare in Shanghai during May; most years see consistent and accelerating warming as the month progresses. Current seasonal forecasts from meteorological services support expectations of above-average warmth for mid-May. The market's 0% pricing suggests traders view a cool spell or temperature suppression as extremely unlikely given May's typical thermal profile and seasonal heating patterns.
What factors could move this market?
Shanghai's climate during mid-May represents a critical transition period between spring and early summer, with the city experiencing rapid increases in warmth as daylight hours extend and solar radiation intensifies. By May 17, daily high temperatures typically settle in the 24–28°C range, with overnight lows around 18–22°C, creating a firmly warm thermal environment. A high of 21°C or below would require significant deviation from normal patterns—either a powerful cold front pushing south from northern China, sustained cloud cover preventing solar heating, or a major low-pressure system bringing rainfall and wind. Historically, such cool days do occur sporadically in Shanghai during May, but their rarity explains why traders have assigned 0% odds to this outcome. Several atmospheric mechanisms could theoretically suppress temperatures: a late-season Siberian cold front, a strong low-pressure system with cloud and precipitation, or unusual upper-level circulation patterns steering cold air southward. However, the typical late-spring pattern involves high-pressure systems anchoring over eastern China, promoting clear skies and steady warming. Shanghai's recent climate history shows increasingly consistent warming patterns by mid-May, with cool-day frequency declining. The market's 0% YES pricing reflects not merely statistical unlikelihood but strong trader conviction about seasonal dynamics. This reflects an assessment that the probability of anomalous cooling sufficient to cap the high at 21°C or below is negligible. Traders appear confident that normal May weather circulation will dominate, preventing disruptions that could delay Shanghai's spring-to-summer warming transition.
What are traders watching for?
Shanghai Meteorological Bureau official high temperature reading released May 17–18
Cold front activity tracking from northern China during May 16–17 overnight passage
Cloud cover and precipitation development affecting solar heating potential on May 17
Upper-level pressure patterns and jet stream positioning over eastern China region
How does this market resolve?
Market resolves YES if Shanghai's official highest temperature on May 17, 2026 is 21°C or below; resolves NO if the high exceeds 21°C, determined by Shanghai Meteorological Bureau official data.
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