Highest temperature in Tokyo on August 15?

Platform comparison

Market context

On 15 August 2026, Tokyo's highest temperature will be measured at Haneda Airport Station and recorded in Weather Underground's Daily Observations table. The market resolves to a specific temperature range in degrees Celsius based on that reading, with settlement occurring at 12:00 UTC on the same day. Resolution hinges on the primary data source (Daily Observations) rather than the summary Day High & Low section, a distinction that matters when discrepancies arise between Weather Underground's display formats.

Tokyo's August temperatures have historically ranged from 32–37°C during mid-month, with extreme heat events pushing toward 40°C becoming more frequent. The current 0% implied probability suggests traders expect temperatures below the lowest offered range, though this reflects either extremely conservative positioning or sparse liquidity rather than meteorological consensus. Comparable August 15th observations from prior years show variability: 2023 recorded 35.1°C, whilst 2022 peaked at 34.5°C. These precedents establish the baseline against which the market's range brackets should be evaluated.

Traders monitoring this market should track Japan Meteorological Agency forecasts released in early August, which typically narrow uncertainty bands significantly. El Niño or La Niña conditions entering 2026 will influence seasonal temperature patterns; current climate indices suggest monitoring through June and July. Urban heat island effects around Haneda, which sits in Tokyo Bay's industrial zone, consistently elevate readings relative to central Tokyo stations. Platform divergence matters here: Polymarket's decimal odds format and Kalshi's binary structure handle temperature ranges differently, affecting how traders price tail-risk scenarios where August heat proves exceptional.

Methodology

This page compares Highest temperature in Tokyo on August 15? 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.

What about Smarkets as an alternative?

Smarkets is a UK betting exchange with a lower default commission (2%) than Betfair. Liquidity on political markets is below Polymarket, comparable to Kalshi. Geo-blocked in many jurisdictions.

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.