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This market asks if Hong Kong's minimum temperature on May 28 will be exactly 22°C—an unusually precise weather prediction. The 1% odds reflect traders' conviction that hitting an exact temperature is extraordinarily unlikely. May 28 falls in Hong Kong's late-May window, typically characterized by warm, humid conditions with overnight lows ranging 23-27°C depending on pressure systems and cloud cover. The market's extreme specificity—requiring not a range like 'below 23°C' or 'above 21°C' but the single precise value 22°C—makes resolution exceptionally challenging. Weather forecasting, even with modern models, rarely predicts exact whole-degree temperatures; typical forecasts give ranges or probabilities of broader bands. The low trading activity ($302 in 24h, $1,033 total liquidity) reflects the niche appeal of such granular daily weather markets. Traders pricing this at 1% are essentially saying that while May 28 may deliver mild conditions, the probability of landing precisely on 22°C is negligible—the temperature curve is more likely to swing 1-5 degrees in either direction.
What factors could move this market?
Hong Kong's geography and climate create distinct late-May patterns. The territory sits at 22°N latitude in the South China Sea region, straddling the transition between spring and the southwest monsoon season (May-September). Overnight temperatures in May typically range 22-28°C, shaped by maritime air masses, cloud cover, and urban heat effects in the densely built harbor areas. A low of exactly 22°C would represent the cool end of this typical range—meteorologically possible but statistically uncommon. Such a reading might occur if a weak cold front or northeasterly surge pushed cool, dry continental air down from Guangdong, suppressing nocturnal temperatures and offsetting the usual maritime warmth. Conversely, the dominant May pattern is steady warm air flow from the South China Sea, with lows remaining 24-27°C as the monsoon gradually establishes itself, bringing frequent cloud and occasional rain. Historical May records for Hong Kong show that exact whole-degree temperatures occur sporadically rather than predictably. Modern weather stations record to 0.1°C precision, but alignment between forecast and reality at the whole-degree level depends on many interactive variables: whether a surface high-pressure system briefly extends southward over the region, if upper-level troughs dig deeper than numerical models project, or whether a rain event temporarily cools the surface layer. The current 1% market pricing implies traders believe May 28 is considerably more likely to fall into the warmer, statistically typical bracket. Recent years' May climate data for Hong Kong shows trend toward earlier monsoon onset and warmer-than-normal nocturnal temperatures, reducing the likelihood of unusually cool nights. The market's structure—betting on a single discrete temperature outcome rather than a range—also inherently lowers the base probability: even if traders assigned 20% collective belief that temperatures fall somewhere in the 22-23°C band, the probability they land exactly on 22°C (if distributed uniformly) would be roughly 2-5%, consistent with observed 1% market pricing. The sparse trading volume ($302 in 24 hours, $1,033 total liquidity) reflects the niche appeal and low information-content of daily exact-temperature weather markets among broader prediction-market participants.
What are traders watching for?
May 28 midnight local Hong Kong time: weather station records the day's minimum temperature; market resolves on exact 22°C reading.
May 20-27: weak cold fronts or surface pressure patterns that might suppress lows from typical 24-27°C range toward 22°C threshold.
24-hour forecast models from May 27: if major meteorology centers predict Hong Kong low near 22-23°C band, market activity may spike.
Recent monsoon onset timing: earlier-than-normal southwest monsoon would drive warmer nights, pushing lows above 22°C and away from YES.
How does this market resolve?
Market resolves on the official Hong Kong Observatory record of the minimum temperature on May 28, 2026 (local time). Resolution requires the low to be exactly 22°C; any other value resolves NO.
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.
