Highest temperature in Tokyo on July 27?

Platform comparison

Market context

Polymarket is pricing **0% YES** for a contract that settles on the highest temperature recorded at Tokyo Haneda Airport being in the relevant Celsius band, and that implies the market is currently treating a July peak within the target range as extremely unlikely. Because the market resolves off the **Wunderground daily history** page for Tokyo Haneda Airport, the practical question for a user holding **USDC on Polygon** is whether the airport’s maximum temperature on 27 July lands inside the contract’s band before the settlement window closes at **12:00 UTC**.

The historical backdrop does not support the idea that Tokyo in July is cool: average July conditions in the city are hot, with daytime temperatures commonly in the upper 20s to low 30s Celsius, and humidity is typically high.[2] Travel guidance for Japan in July also frames the month as peak heat, with advice to start outdoor activity early to avoid afternoon conditions, which is consistent with a market that could still clear a mid- to high-30s outcome if there is a strong heat spike.[3] Wind is usually not the main driver of the daily maximum in Tokyo in July, with average hourly wind speed described as fairly steady through the month.[1]

For traders, the main catalysts are the day’s actual airport observations rather than announcements: the key inputs are the morning heating curve, cloud cover, rain bands, and whether a high-pressure pattern suppresses sea breezes over the airport. The contract’s on-chain conditional tokens simply mirror the weather print, so the relevant live check is the Wunderground temperature page as the day unfolds; once the recorded maximum is locked in there, the market should resolve accordingly.

Sources: 1 · 2 · 3

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

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

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

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.