Highest temperature in Tokyo on August 10?

Platform comparison

Market context

Polymarket currently prices this Tokyo heat contract as a market where **31°C** is the frontrunner at **54%**, with **30°C** next at **38%** on the USDC-denominated, Polygon-settled conditional token market. For traders, that means the crowd is already clustering around a fairly narrow late-summer range rather than pricing a meaningful chance of a cooler or much hotter outcome.

That shape is consistent with Tokyo’s August climatology, where the city’s average high is around the low 30s Celsius and peak summer warmth often sits in the 30–32°C band. Recent comparable data also shows how quickly the upper end can break higher: Tokyo has just logged an extended run of 35°C-plus days, and Japan’s recent heat has produced record national temperatures and widespread heat-related impacts, reinforcing that an outcome in the low 30s is ordinary but not guaranteed in a volatile heatwave month.[3][9][13]

The key catalyst for this market is the actual reading at Tokyo Haneda Airport Station in Weather Underground’s **Daily Observations** table, not the summary high/low box, so intraday spikes matter more than the headline forecast. Traders should watch for shifts in the local forecast, cloud cover, sea-breeze timing, and any weather warnings that alter the afternoon peak; AccuWeather’s same-day forecast has Tokyo around **90°F/32°C** with a **72°F/22°C** low, which sits close to the current market centre of gravity.[1][4][6]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Tokyo on August 10? 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

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.

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.

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%.