Highest temperature in Tokyo on July 23?

Platform comparison

Market context

Tokyo’s **highest temperature** at Haneda on 23 July will be set by how quickly the city heats after sunrise and whether cloud cover or sea-breeze relief arrives before the afternoon peak. The current crowd-implied probability of **0% YES** is not a market that can literally mean no heat; it usually reflects an extremely wide pricing stance, low liquidity, or a contract that traders think is misaligned with the likely temperature band. Tokyo’s July climate is firmly summer-like: average daytime highs are about **30°C**, with humid conditions and frequent rain in the month, which keeps the distribution of outcomes broad but centred in the upper 20s to low 30s Celsius.[2]

For comparable framing, Tokyo weather history shows the city can reach the **high 30s°C** in summer, so a report later in the day can still land well above average if the air mass is hot and skies stay clear.[1] That makes this contract less about the exact morning start and more about whether the day develops into a standard muggy summer session or a hotter-than-normal spike. In cross-platform terms, traders should compare the prediction market’s near-zero implied probability with any sportsbook temperature specials or weather derivatives, because the sharpest divergences usually come when one venue prices the upper tail more aggressively than another. On a day like this, the consensus case is often a narrow band around the climatological high, but the tail risk matters more than the average.

The key catalysts are the local forecast updates for Tokyo Haneda, especially cloud cover, precipitation timing, and wind direction through the late morning and early afternoon. This market settles on the **highest recorded temperature for the day**, so the most relevant dependency is not the morning reading but whether the afternoon maximum is capped by rain bands or pushed higher by strong insolation. Traders should watch the airport forecast cycle, any updated warnings for heat or thunderstorms, and the evolution of humidity and sea breeze; those factors typically move the day’s maximum more than the opening temperature does.

Sources: 1 · 2

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

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

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

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 Kalshi vs Polymarket trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.