Highest temperature in Tokyo on June 30?

Platform comparison

Market context

The real-world event hinges on the highest temperature recorded at Tokyo Haneda Airport Station on 30 June 2026, measured in degrees Celsius and resolved via Wunderground data. This single meteorological observation will determine the market outcome, with the settlement window closing at 12:00 UTC on the same day.

Historically, late June in Tokyo marks the onset of the hot season, with average daily highs exceeding 79°F (26°C) and recent years showing a trend toward higher extremes. In 2025, Japan recorded its highest-ever temperature of 41.2°C, following the hottest June on record, while Tokyo itself logged a record 10 consecutive days above 35°C in August. The current crowd-implied probability of 0% for any specific range suggests traders view the outcome as too uncertain or the range definitions as misaligned with typical late-June variability, despite the clear warming trend.

Traders should monitor the Japan Meteorological Agency’s daily forecasts and Wunderground’s real-time updates for Haneda, as sudden shifts in cloud cover or wind patterns can alter peak temperatures. Recent news from Al Jazeera highlights the intensifying climate crisis in Japan, with record-breaking heat events becoming more frequent, which may influence long-term temperature expectations. Additionally, on-chain mechanics such as USDC settlement flows and BTC/ETH macro movements could affect liquidity, though the primary catalyst remains the weather data itself. Whale flows into weather-related contracts on prediction platforms may signal emerging confidence in specific temperature ranges as the day progresses.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reads Highest temperature in Tokyo on June 30? on-chain. Polymarket's quote comes directly from the Polygon order book — the only comparable venue with on-chain settlement. Kalshi (USD, off-chain), Betfair (GBP/EUR, off-chain) and Manifold (play-money) are listed alongside for venue context. Every CTA routes to BTC Prediction, which mirrors the Polymarket order book directly.

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

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.

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.