Highest temperature in Tokyo on July 30?

Platform comparison

Market context

Tokyo’s daytime high will be measured at Haneda Airport, so the market is really about a single station observation rather than the wider Tokyo area. The crowd is currently pricing the contract at **0% YES**, which implies traders see the relevant temperature bracket as effectively closed off already, even though the outcome will still depend on the official Wunderground reading for the airport site and the settlement cut-off at 12:00 UTC. On the cross-platform picture, that is a clear divergence from the more active Polymarket-style pricing seen in comparable Tokyo heat markets, where July outcomes in the low-30s Celsius have historically drawn the most liquidity and attention[3].

The main historical frame is that Tokyo in late July usually sits in the low-to-mid 30s Celsius, with heatwave days occasionally pushing higher, but Haneda tends to run a little differently from central-city readings because it is a coastal airport location. Tokyo July climate references point to average highs around 30–33°C and only rare spikes above the upper 30s, which is why any market line above the mid-30s would usually require a strong heat surge or unusually persistent subsidence over eastern Japan[12][16]. The broader Japan record heat on 30 July 2025, when the national maximum hit 41.2°C in Hyogo, shows how extreme the regional pattern can become, but it is not a direct guide to Haneda’s own reading[1][2][7].

For traders, the key catalysts are the morning evolution of Tokyo’s forecast, the strength and timing of any Pacific high-pressure ridge, and whether cloud cover or sea-breeze moderation limits afternoon warming. Tokyo forecast tables from AccuWeather and WeatherSpark suggest late-July highs commonly sit in the low 30s Celsius, so any move into a much hotter range would need fresh evidence of stronger-than-expected heating or delayed marine influence[6][8][16]. With settlement tied to the official daily maximum at Haneda, the only decisive inputs are the airport’s observed readings and any late-day weather update that changes expectations before the market closes[10].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Tokyo on July 30? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Best Prediction Markets 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.