Highest temperature in Tokyo on July 10?

Platform comparison

Market context

The underlying event is the highest temperature recorded at Tokyo Haneda Airport on 10 July 2026, measured in degrees Celsius and sourced from Wunderground. With the crowd-implied probability of hitting 30°C or higher sitting at 0% YES, the market currently treats any significant heat spike as virtually impossible, despite July being Tokyo’s peak summer month.

Historical data frames this probability as an outlier. Tokyo Haneda’s July 2026 forecast shows daily highs ranging from 76°F to 91°F (24°C to 33°C)[1], while Japan’s all-time record reached 41.2°C in Tamba City in 2025[5]. Even the Met Office lists a 32°C maximum for Haneda in its current forecast[2]. Given that Tokyo routinely hits low 30s in July with high humidity[9], pricing 30°C at 0% contradicts both seasonal norms and recent national extremes, suggesting the market may be misreading the bracket structure or ignoring thin volume signals[10].

Traders should monitor the Japan Meteorological Agency’s daily heat advisories and Wunderground’s real-time updates for Haneda, as sudden shifts in cloud cover or wind patterns can trigger rapid temperature spikes. No major climate announcements are scheduled, but whale flows into weather derivatives on crypto exchanges like Bitget could signal emerging confidence[4]. In a macro context, if BTC/ETH funding rates tighten and USDC settlement volumes surge, liquidity may flow into niche weather contracts, potentially correcting the 0% mispricing before the 2026-07-10 settlement window closes.

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.

Can I use Bitcoin directly?

No, Polymarket operates exclusively in USDC on Polygon. You can bridge BTC to USDC via an exchange or bridge service and deposit on Polygon — typically 10-30 minutes processing time.

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.