Highest temperature in Tokyo on August 18?

Platform comparison

Market context

Tokyo's highest temperature on 18 August 2026 will be measured at Haneda Airport Station using Weather Underground's Daily Observations table, with settlement occurring at midday UTC on that date. The market currently shows 0% probability assigned to any outcome, suggesting either minimal trading activity or extreme uncertainty about the eventual temperature range.

August temperatures at Tokyo Haneda have historically ranged between 28°C and 36°C during the peak summer season, with daily highs typically clustering in the 32–35°C band. The 2023 summer saw several days exceed 35°C as part of a broader heatwave across Japan, whilst cooler August days have occasionally dipped to 28–30°C during periods of cloud cover or typhoon influence. These historical patterns establish the baseline against which traders should calibrate their expectations for next year's conditions.

The primary catalyst affecting this market will be seasonal weather patterns developing in late July and early August 2026. Traders should monitor Japan Meteorological Agency forecasts and tropical cyclone activity in the Western Pacific, as typhoons or monsoon troughs can substantially suppress daytime temperatures. Additionally, the transition between the summer high-pressure system and autumn weather systems typically begins mid-to-late August, potentially introducing variability. Weather Underground's historical data for Haneda will provide the definitive settlement source, making the specific station's microclimate—influenced by proximity to Tokyo Bay and airport operations—more relevant than broader Tokyo metropolitan area forecasts.

Methodology

This page tracks Highest temperature in Tokyo on August 18? across four political prediction venues. Live odds come from the Polymarket order book (the deepest political prediction-market book). Kalshi is the CFTC-regulated US alternative, Betfair the established UK sports-exchange with politics markets, Manifold the open play-money variant. For users geo-blocked from Polymarket directly, brokers like Election Predictions UK provide a 0%-fee route into the same order book.

Resolution & payout

For political markets the resolution source is decisive. Polymarket defines a concrete source per contract (e.g. AP, Reuters, official electoral commission) and uses the UMA Optimistic Oracle as the on-chain dispute mechanism. With a clearly defined outcome the USDC payout lands within minutes of the final confirmation.

UK Frequently Asked Questions

How accurate are political prediction markets?

Historically more accurate than polls. Polymarket's Brier score on US 2024 elections was ~0.11 — better than 538 (~0.14) and every mainstream poll. Markets aggregate information with real skin in the game.

Can prediction markets influence election outcomes?

Markets reflect expectations rather than create them. Studies show public-facing markets can anchor expectations, but don't influence the underlying outcome. Political markets are information, not advocacy.

How fast do political markets react to news?

High-liquidity markets move within seconds to minutes. A Trump tweet on the economy can shift the "Trump 2024" market 2-5 points before mainstream media has written anything.

Why do Polymarket and Kalshi differ on elections?

Kalshi must follow CFTC compliance — strict definitions, clear resolution sources, US citizens only with KYC. Polymarket operates globally without CFTC oversight — deeper liquidity, but also higher regulatory risk.

Are UK election prediction markets available from the UK?

Yes. Betfair Exchange and Smarkets offer UKGC-regulated UK election markets (seat counts, party share, constituency results). Polymarket also lists UK election contracts with deeper global liquidity. Betfair winnings are typically tax-free for UK individuals; Polymarket profits are subject to HMRC CGT.