Highest temperature in Tokyo on August 5?

Platform comparison

Market context

Tokyo’s reading at Haneda will be decided by the day’s single highest observed temperature, so the market is really about whether the airport reaches a typical August peak or stays in a more muted range. Seasonal normals for Tokyo sit around 31°C/88°F for August highs, with overnight lows near 24°C/75°F, and current city forecasts cluster close to that pattern rather than implying an extreme outlier.[1][7][16]

That is why a **0% YES** price can be read as a statement that the market is already discounting a bracket above the relevant threshold, not as a view that Tokyo will be cool. Japan Meteorological Agency daily data show Tokyo-area summer highs can still vary several degrees day to day, while Haneda itself often tracks a few tenths below inland wards because of its coastal position; in practice, traders usually focus on whether sunshine, weak winds and any late-morning clearing can push the airport above the key band before the settlement cut-off.[10][14]

For catalysts, watch the latest hourly forecast updates, cloud cover and rain chances through the morning, because the contract settles on the day’s maximum rather than a noon reading.[2] Any shift in the forecast from overcast to clearer conditions matters more than the broad monthly outlook, and today’s Tokyo hourly forecast already points to warm afternoon readings around 88°F with no rain chance at the city level.[2] On-chain, this is a USDC-settled weather contract, so moves in BTC or ETH spot and funding rates only matter indirectly if they change overall risk appetite or drive rotation into small-bet prediction market flow.

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.

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.

How volatile are crypto prediction markets?

Crypto markets react to spot prices — a 5% BTC move typically shifts a "BTC above X by date" market 10-20%. Polymarket crypto market liquidity is usually six-figure USD, sufficient for active trading.

Which crypto markets exist on Polymarket?

Currently active markets include BTC/ETH/SOL price targets, halving dates, ETF approvals, hard-fork outcomes and Layer-2 TVL thresholds. The list updates weekly; biggest volume sits on BTC and ETH price forecasts.