Highest temperature in Tokyo on August 8?

Platform comparison

Market context

Tokyo’s daytime peak for 8 August is being judged against a **station observation**, not a forecast summary, so the final number will depend on the highest reading recorded at Tokyo Haneda Airport Station in Weather Underground’s Daily Observations table before the settlement cut-off. Current public forecasts are already clustered in the low-to-mid 30s Celsius, with AccuWeather showing around 92–94°F and Weather Underground’s Tokyo page sitting near 92°F/77°F, which puts the implied outcome squarely in the hotter summer bands rather than in a mild-range result.[2][3][8]

Historically, early-August Tokyo is one of the most reliable heat-season periods in Japan, with climatology and travel-weather guides both pointing to average daytime temperatures around 29°C and frequent intraday spikes above 33°C.[12][16][18] That makes the market’s 0% YES pricing notable only if the contract is effectively asking whether a specific temperature band is already locked in; otherwise, the live weather profile argues for a result driven by whether the airport station tops out at 31–32°C, 33–34°C, or above, rather than any extreme outlier. For on-chain traders, this is a straightforward USDC settlement event: the final value is binary only at expiry, while the path there is dominated by the meteorological read rather than BTC or ETH direction.

The main catalysts are the day’s hourly heat build-up, any late-afternoon cloud cover or rain, and whether thunderstorms clip the maximum before the official observation window ends. Current forecasts show low precipitation odds through the day but some late-night storm risk, which matters less if the maximum arrives before evening.[2][3][7][9] In crypto terms, there is no obvious macro linkage unless a broader risk-off move changes liquidity or attention across markets; funding and whale flows are unlikely to matter here unless they affect how thinly this niche market is priced.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically this overview focuses on on-chain pricing: Polymarket's live mid comes from the Polygon conditional-token order book and settles automatically in USDC. The other three venues — Kalshi, Betfair, Manifold — sit alongside as off-chain reference points so you can see how the contract translates across regulatory and settlement regimes.

Resolution & payout

Settlement is on-chain via UMA Optimistic Oracle. A proposer posts the outcome with a bond, a two-hour dispute window opens, then the smart contract lifts winning conditional tokens to 1 USDC and sends payments to holders' wallets automatically. No withdrawal fees beyond Polygon gas.

Off-chain venues (Kalshi, Betfair, Smarkets) settle in local fiat through bank-side clearing — faster than SWIFT, slower than on-chain. Manifold pays no real cash.

UK Frequently Asked Questions

What are crypto prediction markets?

Crypto prediction markets are on-chain smart contracts where you buy YES or NO shares on a future crypto event (e.g. "BTC above $100k by year-end"). The market price between 0¢ and 100¢ is the implied probability.

What does a transaction cost on Polygon?

Polygon gas is typically under $0.01 per transaction. A full trade cycle (Approve + Order + Fill) totals around $0.03 — compared to $5-50 on Ethereum mainnet.

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%.