Highest temperature in Tokyo on August 7?

Platform comparison

Market context

Polymarket is pricing the Tokyo Haneda Airport Station temperature contract at **0% YES** right now, which means the market is effectively saying the highest reading on the Wunderground daily observations page will *not* land in the YES range. The contract settles in USDC on Polygon via conditional tokens, so the key variable is the exact station-day maximum shown in Wunderground’s **Daily Observations** table, not any broader Tokyo headline figure or day-high summary.

That zero price sits against a climate backdrop where Tokyo’s August highs are normally well into the 30s Celsius. Recent forecast-style sources for early August 2026 point to daily highs around 30–32°C, with some broader monthly guides putting Tokyo’s August daytime range closer to 31–33°C and noting frequent humidity and rain. Comparable summer days in the city can still spike above the average, so a contract like this is usually read as a narrow range bet on whether the official station maximum clears a specific threshold, rather than a simple “hot or not” call.

For traders, the main catalysts are the day’s realised weather at Haneda, plus any late-morning convective showers, sea-breeze effects, or typhoon-adjacent cloud cover that can suppress the peak reading before the market’s settlement window closes at 12:00 UTC. Because the resolution source is a station-specific Wunderground history page, the relevant check is the intraday maximum recorded there, not the displayed summary high elsewhere, and that distinction matters if the day’s headline Tokyo weather and the station log diverge.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Tokyo on August 7? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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.

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 Kalshi 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%.