Highest temperature in Tokyo on July 31?

Platform comparison

Market context

Tokyo’s settlement point is the **daily maximum at Haneda Airport**, so the relevant number is the single highest reading posted on Wunderground for 31 July, not the citywide average or the noon temperature. For a programmatic workflow, that means polling the history page near the end of the observation day, extracting the top Celsius value for the station, and only then mapping it to the market’s range bracket. A 0% crowd-implied probability is consistent with a market that is still open before the day’s final heat peak has been observed.

The historical frame points to a warm Tokyo summer but not a straightforward path to an extreme outlier. Tokyo’s July climate norm is around 30°C for highs, while recent July data for the city show daily maxima commonly in the low-to-mid 30s, with some late-month spikes above 35°C and, in one recent 31 July example, a 31.1°C high at Tokyo Haneda in 2025 and 31.6°C in another 2025 dataset for Haneda[8][10]. Broader Japan heat coverage has also shown the country setting a new national high of 41.2°C in Tamba on 30 July 2025, which matters because regional heat surges can lift Tokyo readings even if Haneda itself remains below national extremes[9].

The main catalysts are ordinary weather drivers rather than scheduled announcements: the position of the Pacific high, cloud cover, sea-breeze moderation, rainfall bands, and any late-afternoon convective bursts that can cap the day’s maximum. A trader watching this programmatically would want live hourly obs from Haneda, nearby synoptic forecasts, and updates from the Japan Meteorological Agency, then compare them with the Wunderground daily history entry once the maximum is locked in[5][8][12].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Tokyo on July 31? 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 Kalshi Fees, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

FAQ

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'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.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

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.