Highest temperature in Tokyo on August 1?

Platform comparison

Market context

Tokyo’s daytime heat on 1 August is usually well into the low 30s Celsius, with August averages around 31°C for the city and typical highs often above 33°C in the peak heat of the month.[13][15] Current August forecasts for Tokyo point to highs in roughly the low-to-mid 30s Celsius, which is consistent with the historical summer pattern rather than an outlier cool spell.[1][14]

That framing matters for the 0% implied probability on the lowest range: Tokyo’s August record history shows that the city can produce much hotter outcomes, with the all-time August high at 37.3°C, but the normal distribution of August highs is still centred around the low 30s.[2][10] For a market settling on the highest temperature at Haneda, the relevant question is less whether it will be hot and more whether the day produces a brief spike above the usual August band, because the contract resolves to the day’s maximum rather than the average.[11][15]

Traders should watch the local forecast evolution, especially any heat advisory or subtropical ridge strengthening over eastern Japan, because that can push the afternoon peak a few degrees higher even if the morning starts milder.[1][12] The settlement source is Wunderground’s Tokyo Haneda Airport Station history page, so the key dependency is the station’s recorded maximum during the full day rather than a citywide estimate, with the result finalised from that single official history entry.[1]

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.

FAQ

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.

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.

How does UMA secure the resolution?

The UMA Optimistic Oracle uses a bond system: a proposer posts a bond, a two-hour challenge window opens. On dispute the losing side forfeits the bond — financial incentive for honest resolution.

Are crypto prediction markets taxable in the US?

In the US, prediction market gains are typically treated as ordinary income or short-term capital gains depending on holding period. Consult a tax professional for your specific situation — we cannot provide tax advice.