Highest temperature in Tokyo on August 8?

Platform comparison

Market context

Tokyo’s top temperature on 8 August is a straightforward weather settle, but the market is pricing it as a near-certainty because the day is already hot and the published forecasts cluster around the low-to-mid 30s Celsius. AccuWeather’s August view shows Tokyo’s 8 August high at 94°F, while timeanddate’s Tokyo forecast currently points to 94°F/75°F with afternoon temperatures around 92–93°F, both consistent with a peak in the low 30s Celsius rather than anything exceptional.[1][2] Weather Underground’s live Tokyo page at 9:39 a.m. JST already shows 92°F, implying the contract’s target range is likely in play early in the day.[4]

Historical context does not suggest a wide dispersion of outcomes for a summer Tokyo contract: August is normally Tokyo’s hottest month, with average highs around 30–31°C and frequent humidity-driven heat spikes.[9][11][14] WeatherSpark notes that 8 August is also the muggiest day of the year in Tokyo, which matters because muggy mornings often translate into strong afternoon heating if cloud cover stays limited.[13] That backdrop helps explain why the crowd-implied 0% YES looks misaligned with mainstream weather expectations; compared with the forecast sources, it reads more like a stale or inverted market than a genuine view on a cool day.

The main catalysts are the intraday weather evolution and, for settlement, the exact Weather Underground Daily Observations entry rather than the summary high/low banner. If clouds, sea breeze, or rain arrive earlier than forecast, the eventual maximum could undershoot the headline forecast, but current hour-by-hour readings still favour a solid afternoon peak.[2][4] Traders should watch the sequence of updates through local afternoon, because the final observed maximum at Tokyo Haneda Airport Station is what resolves the range, not the broader Tokyo city forecast.[10][12]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Tokyo on August 8? 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.

FAQ

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 vs Polymarket. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Kalshi vs Polymarket trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.