Highest temperature in Tokyo on August 19?

Platform comparison

Market context

Tokyo's highest temperature on 19 August 2026 will be measured at Haneda Airport Station and recorded in Weather Underground's Daily Observations table, with settlement determined by that primary source rather than the Day High & Low summary section. The market currently shows 0% implied probability across all temperature ranges, suggesting either insufficient liquidity or a technical listing issue rather than genuine certainty about the outcome.

Historical August temperatures at Haneda provide the baseline for calibration. Tokyo typically experiences peak summer heat in mid-August, with daily highs ranging from 32–36°C during normal conditions, though extreme heat events have pushed readings above 38°C in recent years. The Japan Meteorological Agency recorded 35.1°C at Haneda on 19 August 2023 and 34.2°C on the same date in 2022, establishing a recent precedent band. Traders comparing this market across platforms—Polymarket's decimal odds format versus Kalshi's binary structure, or Betfair's commission-based model—should note that Weather Underground's specific measurement protocol creates resolution risk absent from more standardised benchmarks like national weather service aggregates.

The 2026 forecast window remains too distant for reliable seasonal prediction models, though La Niña or El Niño conditions developing through 2025–2026 could shift average temperatures by 1–2°C. Traders should monitor Japan Meteorological Agency seasonal outlooks issued in June and July 2026, as well as any typhoon activity in early August that could suppress peak temperatures through cloud cover and precipitation. The settlement window closes at midday UTC on 19 August, creating a hard deadline for final measurements.

Methodology

We read Highest temperature in Tokyo on August 19? from four platform perspectives: Polymarket (on-chain CLOB), Kalshi (CFTC-regulated exchange), Betfair Exchange (sports book exchange), Smarkets (peer-to-peer betting exchange). Polymarket's live mid is the canonical probability; the side-by-side columns benchmark fees, KYC, settlement currency and deposit rails so you can choose the venue that fits your jurisdiction and trade size.

Resolution & payout

Settlement is the biggest difference between the four platforms: Polymarket on-chain in USDC (instant), Kalshi USD via CFTC (T+1), Betfair and Smarkets in local currency via bank withdrawal (T+1 to T+3). On-chain settlement clears in minutes — the fastest payout path of the four.

FAQ

Polymarket vs Kalshi — which is better?

Depends on your location. Kalshi is CFTC-regulated, US-only with full KYC. Polymarket is global, on-chain, no KYC up to $1,500. Polymarket has ~10x higher liquidity but higher regulatory risk.

What does Polymarket cost vs Kalshi?

Polymarket: 0% fees, only Polygon network costs (~$0.01/trade). Kalshi: up to 7% per trade plus spread. For high-frequency traders, Polymarket is dramatically cheaper.

Which platform has the deepest liquidity?

Polymarket — by a wide margin. Top markets reach $50-500M volume, Kalshi ~$200M cumulative, Betfair similar. Deeper liquidity means your trade moves the quote less.

Is Betfair a Polymarket alternative?

Only partially. Betfair Exchange is UK-focused with a sports-betting emphasis; they have politics markets but with thinner liquidity than Polymarket. Settlement in GBP/EUR, 2-5% commission on winnings.

Which platform supports Klarna/SOFORT?

Directly: none. Polymarket accepts only USDC on Polygon. Robinhood Prediction Markets offers a fiat on-ramp via Klarna or SOFORT (DE/AT/CH) and converts internally to USDC for the Polymarket order book. T+1 processing.