Highest temperature in Tokyo on May 25?

Platform comparison

Active sub-markets

Market context

On 25 May 2026, Tokyo's highest temperature will be recorded at Haneda Airport Station and fall into one of several defined ranges. The settlement hinges on Weather Underground's historical data feed for that specific location, which captures intraday highs with precision. This market differs markedly across platforms: Polymarket displays decimal odds and charges a 2% taker fee, whilst Kalshi presents implied probabilities directly and operates under CFTC oversight with different fee tiers depending on contract notional value. Betfair and Smarkets, both UK-regulated, show fractional odds by default and levy commission on net winnings rather than at point of trade, creating distinct cost structures for active traders.

Tokyo's May temperatures have ranged from 18°C to 32°C over the past two decades, with an average high near 26°C. The 0% crowd probability on this market likely reflects either thin liquidity or a specific temperature threshold set so high that historical precedent makes it implausible. Comparing this across books reveals how different platforms' liquidity pools and user bases price tail-risk differently; Smarkets' smaller user base sometimes leaves extreme ranges underpriced relative to Kalshi's institutional flow.

Traders should monitor Japan Meteorological Agency forecasts released in early May, which typically narrow uncertainty bands significantly. El Niño or La Niña patterns in the preceding months will influence seasonal temperature trends. Haneda's urban heat island effect and proximity to Tokyo Bay mean local conditions can diverge from broader Kanto region forecasts—a detail that affects how traders on each platform calibrate their models.

Methodology

We read Highest temperature in Tokyo on May 25? from four platform perspectives: Polymarket (on-chain CLOB), Kalshi (CFTC-regulated exchange), Betfair Exchange (sports book exchange), Smarkets (peer-to-peer betting exchange). Polymarket's live quote comes directly from the Polygon order book; the other three are listed with their platform attributes — fees, KYC, settlement currency, payment options — because a 1:1 contract comparison without API access would be guesswork.

Resolution & payout

Settlement is the biggest difference between the four platforms: Polymarket on-chain in USDC (instant), Kalshi USD via CFTC (T+1), Betfair and Smarkets in local currency via bank withdrawal (T+1 to T+3). PolyGram routes every trade directly into Polymarket's on-chain settlement, which is why payouts land fastest.

FAQ

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.

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 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 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.