Highest temperature in Tokyo on June 30?

Platform comparison

Market context

The real-world event centres on the highest temperature recorded at Tokyo Haneda Airport on 30 June 2026, with current Japan Meteorological Agency forecasts predicting cloudy skies and daytime highs in the mid-to-upper 20s Celsius[1]. Historical data from recent years shows June in Tokyo typically ranges between 19–27°C, though extreme outliers have occurred, such as Japan’s hottest June on record in 2025 when Nerima Ward hit 38.6°C and Kumagaya City reached 39.1°C[8]. The current market probability of 0% for any outcome above 27°C aligns with the mid-to-upper 20s forecast, yet the 99% frontrunner for exactly 27°C suggests traders are pricing in a narrow margin above average[1].

A power-user approaching this programmatically would monitor real-time Wunderground feeds for the Haneda station, cross-referencing with NWS time-series data for wind, humidity, and cloud cover[2][3]. Key catalysts include the onset of the rainy season’s end, which typically begins around 29 June and could suppress temperatures, alongside any sudden shifts in the Pacific high-pressure system that might trigger heatwaves[9][10]. Recent reports from The Watchers News highlight that Japan has endured its three hottest summers on record, underscoring the volatility of temperature spikes even during cloudy periods[8]. Traders should watch for official announcements from the Japan Meteorological Agency regarding heat advisories, as these often precede rapid temperature surges.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Tokyo on June 30? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Polymarket App UK, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

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.

Do I need to KYC for this market?

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

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.