Highest temperature in Tokyo on August 11?

Platform comparison

Market context

Tokyo's highest temperature on 11 August 2026 will be measured at Haneda Airport Station and recorded in Weather Underground's Daily Observations table, with settlement occurring at midday UTC. The 0% implied probability reflects either extreme confidence in a specific temperature band or minimal trading activity on this niche weather contract. Cross-platform comparison reveals structural differences: Polymarket displays decimal odds alongside probabilities, whilst Kalshi emphasises percentage-based implied odds; Betfair and Smarkets offer tighter spreads on weather contracts but typically require stricter KYC verification for non-US traders, potentially limiting liquidity on regional temperature ranges.

Historical August temperatures at Tokyo Haneda show a median high of 32–34°C, with extremes ranging from 29°C to 37°C over the past two decades. The 2023 August peak reached 35.1°C, whilst 2022 recorded 36.4°C during an exceptional heat event. Current zero probability on this market likely indicates either that traders have concentrated positions in adjacent temperature bands or that the market has insufficient depth to reflect genuine uncertainty across all ranges. Resolution hinges entirely on Wunderground's Daily Observations table rather than the Day High & Low summary, a distinction that matters when automated weather stations report sub-hourly fluctuations.

Traders should monitor Japan Meteorological Agency forecasts released in late July 2026, which typically provide 10-day outlooks with 70–80% accuracy for daily highs. Pacific typhoon activity during early August could suppress temperatures by 2–4°C, whilst high-pressure systems from the continent would elevate readings. Fee structures vary meaningfully: Polymarket charges 2% on winnings, Kalshi takes 5%, and Betfair's commission scales with volume, making small-stake weather bets more cost-effective on Polymarket for retail traders.

Methodology

This page compares Highest temperature in Tokyo on August 11? specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. The live probability is the Polymarket mid; the comparison columns summarise each venue's fee structure, KYC, settlement currency and payment rails. Every CTA routes to Robinhood Prediction Markets, which mirrors the Polymarket order book at 0% fees.

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.

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.

Are all these platforms regulated?

No. Kalshi is CFTC-regulated (US). Betfair and Smarkets are UK Gambling Commission licensed. Polymarket operates without explicit regulation — a different risk profile than a regulated sportsbook.

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.