Highest temperature in Tokyo on May 22?

Platform comparison

Active sub-markets

Market context

Tokyo Haneda Airport has already reported its daytime high for 22 May, and the market will settle on the Celsius band containing that final maximum. With the settlement window ending at 12:00 UTC, the relevant reading is the one recorded during the Tokyo day, not any later evening cooling. For late May in Tokyo, long-run climate norms point to mild-to-warm conditions rather than extreme heat: typical daytime highs are in the low-to-mid 20s Celsius, with nights still relatively cool. That makes the broad middle ranges the natural reference point, while very low outcomes are usually associated with persistent cloud, rain, or a notably cool airmass.

The crowd has priced the 16°C band at 100%, which suggests the live reading or official projection has been unusually subdued relative to seasonal averages. That sits below common May benchmarks for Tokyo, where highs around 20–25°C are more typical and brief warmer spells can push into the upper 20s. A 16°C maximum would be more in line with a cool, damp spring day than a standard late-May afternoon, so the key question is whether the airport station saw prolonged rain, marine air, or an early-day peak before temperatures stalled.

Traders should watch the Tokyo Haneda observation feed and any short-range updates from Japanese forecasters in case a front, sea breeze, or rain band limits the afternoon climb. The outcome also depends on the exact final Wunderground history entry for the station, since the market resolves to the highest temperature recorded there on the day, not a city-wide average. If showers cleared early or sunshine held longer than expected, the high could still end up a few degrees above the market’s current favourite.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Tokyo on May 22? 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

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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.

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.

What does it cost to trade on PolyGram?

Zero. PolyGram routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

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.