Highest temperature in Tokyo on May 25?

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Active sub-markets

Market context

Tokyo's weather on 25 May 2026 will determine which temperature band captures the day's peak reading at Haneda Airport Station. Late May sits within Tokyo's late spring period, typically characterised by warming trends ahead of the rainy season (tsuyu) that arrives in early June. Historical data from the Japan Meteorological Agency shows May temperatures at Haneda range between 20–28°C on average, with occasional spikes to 30°C during warm years. The 0% crowd probability suggests traders are either awaiting resolution data or treating the market as a calibration exercise rather than an active pricing mechanism.

For programmatic traders, the key dependency is Weather Underground's historical archive, which updates once daily observations are finalised—typically by midday UTC on 26 May. Automated feeds can pull this data via their API, though the resolution window closes at 12:00 UTC on settlement day, leaving minimal margin for late corrections. The Japan Meteorological Agency publishes daily summaries independently, providing a secondary verification source. Traders building conditional orders should account for the fact that May 2026 forecasts remain speculative; seasonal models from early 2026 will offer better signal than current long-range projections. Recent El Niño patterns have influenced North Pacific weather systems, though their persistence through May 2026 remains uncertain.

Methodology

We track Highest temperature in Tokyo on May 25? on the five venues with material liquidity for prediction markets. Live odds come from the Polymarket Polygon order book — the only source that ships real-time data under an open licence. For Kalshi, Betfair and Manifold we list platform attributes (fee, KYC, settlement, payment) instead of fabricated odds, because their APIs use non-comparable contract definitions.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

FAQ

Where can I trade this market with the lowest fees?

On PolyGram, which mirrors the Polymarket order book at 0% fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

PolyGram is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.