Guangzhou, China's largest subtropical city, experiences warm-to-hot weather throughout May as late spring transitions into early summer. A maximum temperature of 22°C or below would be unusually cool for this period, when historical May averages sit 5–10°C higher. The 0% YES odds reflect overwhelming trader conviction that real-world conditions will exceed this threshold—a reasonable assessment given seasonal norms. Currently priced at 0¢, the market signals near-certainty that Guangzhou will warm significantly above 22°C on May 18. The odds trajectory suggests confidence in typical subtropical May patterns holding steady, despite occasional weather disruptions that might temporarily suppress temperatures.
What factors could move this market?
Guangzhou's climate in May is governed by its subtropical monsoon location along the Pearl River Delta and South China's coastal region. The month marks the transition from spring into early summer, where diurnal highs progressively climb from the mid-20s toward 28–32°C as solar angle steepens and maritime moisture increases. A maximum of 22°C would require unusual meteorological circumstances—either a rare late-spring cold front pushing deep southward, a tropical cyclone remnant advecting cooler air, or an anomalous upper-level trough disrupting normal thermal patterns. Such events occur, but infrequently; historical May data from recent decades shows temperatures below 22°C on any single day occur in perhaps 5–10% of years, typically only with significant synoptic disruption. The broader climatological picture strongly favors warmth. Guangzhou sits in a thermal pocket influenced by the warm South China Sea, which supplies persistent maritime air masses with little capacity for cooling. The current 0¢ YES pricing reflects this fundamental asymmetry: traders perceive an exceptionally low-probability outcome relative to the baseline seasonal expectation. What could push toward YES? An unexpected upper-level trough, a stalled frontal system, cloud cover and rain from tropical activity, or early-season cyclone interaction might cool the region. Conversely, high-pressure ridging, clear skies enabling maximum solar heating, and typical subtropical circulation patterns all favor NO. Recent spring weather patterns matter: if 2026 spring has trended warmer-than-average or upper-level ridging has dominated, traders may be pricing continuation of that trend. The market's extreme YES underpricing also signals confidence in the underlying forecasting logic—that weather models, climatological precedent, and seasonal patterns all point decisively away from 22°C. Any last-minute tropical cyclone development or unexpected atmospheric disruption before May 18 could shift sentiment, but the consensus read remains: Guangzhou will almost certainly exceed 22°C.
What are traders watching for?
Official Guangzhou daily high temperature reported by the Guangzhou Meteorological Bureau on May 18; timing and accuracy of morning/afternoon readings
Late-breaking tropical cyclone activity or upper-level trough development affecting southern China in the 48 hours before May 18
Real-time weather model consensus and CMA (China Meteorological Administration) forecasts issued May 17–18, which may shift trader expectations
Unusual atmospheric disruptions such as cold-front intrusion, jet-stream displacement, or unexpected cloud cover in the 24 hours prior to resolution
How does this market resolve?
Market resolves YES if Guangzhou's highest temperature on May 18, 2026 (China Standard Time, UTC+8) is 22°C or below, as recorded by the Guangzhou Meteorological Bureau or equivalent official Chinese weather authority. NO if the daily maximum exceeds 22°C.
Polymarket Trade is an independent third-party interface to the Polymarket CLOB prediction market exchange on Polygon — not affiliated with Polymarket, Inc. Prediction markets aggregate trader expectations into real-time probability estimates. 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. Polymarket Trade is non-custodial — your funds never leave your wallet. Open the full interactive page linked above to place orders, see order book depth, and execute a trade.
