Highest temperature in Tokyo on August 7?

Platform comparison

Market context

Tokyo’s afternoon maximum on 7 August will be the settling figure, taken from Weather Underground’s **Daily Observations** for Tokyo Haneda Airport rather than any summary high/low banner. For a programmatic approach, the cleanest workflow is to poll the observation table late in the local afternoon and map the highest Celsius reading into the market’s outcome band, because the resolution standard is the recorded station observation, not a forecast or city-wide average.

The current 0% YES pricing is hard to reconcile with seasonal context: August in Tokyo is typically hot, with forecast and climatology sources putting daytime highs around the low 30s Celsius and occasional spikes into the mid-30s, while overnight lows remain warm. AccuWeather’s August outlook for Tokyo shows daily highs ranging from 82° to 90°F, and other seasonal guides place Tokyo’s August maxima around 31-32°C, with hotter days sometimes exceeding 35°C.[1][15][17][18] That means the market is not asking whether Tokyo will be warm, but whether Haneda’s recorded peak lands in the specific temperature bucket used by the contract.

Traders watching this mechanically should track the day’s synoptic setup rather than the calendar alone: cloud cover, rain bands, and onshore flow can suppress the peak at Haneda, while late-morning sun can still lift the station reading before showers arrive. The Japan Meteorological Agency’s Tokyo outlook has been mixed recently, with cloudy and shower-prone conditions appearing in the short-range forecast, and BBC/AccuWeather observations show temperatures already in the low-to-mid 20s Celsius overnight, leaving room for a meaningful intraday rise if clouds thin.[6][10][13] A bot or conditional order setup should therefore watch for the first confirmed observation of the day’s high in the Daily Observations table, because that is the number that matters for settlement.

Sources: 1 · 2 · 3 · 4 · 5

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.

UK Frequently Asked Questions

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Polymarket Review UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

Is Polymarket legal in the UK?

Polymarket is accessible to UK traders but is not UKGC-licensed. It operates under US CFTC jurisdiction. UK residents face no domestic legal prohibition on using it, but UKGC consumer protections do not apply. For UKGC-regulated alternatives, Betfair Exchange and Smarkets offer similar prediction-style markets.

Do I pay tax on prediction market profits in the UK?

UKGC-licensed platform profits (Betfair, Smarkets) are typically tax-free gambling winnings for UK individuals. Polymarket profits involve USDC crypto transactions, which HMRC treats as Capital Gains Tax events. Keep full transaction records and report via Self Assessment if gains exceed £3,000 per tax year.

How do I deposit on Polymarket from the UK?

UK traders typically fund Polymarket via Coinbase UK, Kraken or Revolut — buying USDC with GBP and transferring to a Polygon-compatible wallet (MetaMask, Coinbase Wallet). Polymarket's onboarding walks you through the bridging process. Typical GBP-to-USDC conversion costs 0.5–1%.