Highest temperature in Tokyo on August 6?

Platform comparison

Market context

Tokyo’s peak temperature will be set by the highest reading at Haneda Airport, and the contract resolves against that station data rather than a citywide average. With the market still showing 0% for **YES**, the crowd is effectively pricing in a very low chance that the final reading lands in the targeted bracket, even though early-August heat in Tokyo is usually severe and can still change quickly through the day. JMA daily observations for Tokyo already show highs in the mid-to-upper 30s at several nearby locations on 1–2 August, while Haneda itself has posted **35.6°C** and **33.0°C** on those dates, indicating that a high-30s outcome is not impossible if conditions remain clear and humid.[1]

The broader seasonal frame is hot enough that traders should read the price more as a live weather call than a calendar given. Tokyo’s August average maximum is about **31°C** in climatology, but forecasters have been pointing to an above-normal summer, and Tokyo’s 6 August forecast sits around **32°C** with sunshine in the day’s outlook.[9][15][3] That makes the most relevant comparable cases the other very warm early-August outcomes, particularly when inland heating pushes city temperatures above the airport reading; the key question is whether Haneda can convert the day’s warmth into a top-end observation near the higher brackets rather than a routine low-30s result.[1][3]

For a trader, the main catalysts are the morning-to-afternoon evolution of cloud cover, sea breeze and any rain bands over the Tokyo Bay area, because Haneda can lag the hotter inland wards when onshore flow strengthens. The contract settles in USDC on-chain, so the practical market drivers are the same inputs that move any weather book: fresh forecast updates, late-run temperature revisions, and any shift in the exchange order book as the day progresses. On the crypto side, there is no direct BTC or ETH link in the settlement itself, but broader risk appetite and funding conditions can still affect liquidity and slippage in the market throughout the session.

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.

Why USDC and not ETH or USDT?

USDC is the Polygon standard — audited reserves (Circle, monthly attestation), deepest order book, low gas costs. ETH volatility would distort probability quotes; USDT has thinner Polygon liquidity than USDC.

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%.