Highest temperature in Tokyo on August 1?

Platform comparison

Market context

Tokyo’s outcome will be set by the day’s **highest air temperature at Haneda Airport**, so the key question is not whether it feels hot in the city centre, but whether a specific reading lands in one Celsius band or another before the noon UTC cut-off. August is typically Tokyo’s hottest month, with average highs around 31–33°C and occasional spikes into the mid-30s, while the all-time Tokyo record is 37.3°C, which keeps the upper bands alive even if they are not the modal outcome.[1][2][10][12]

The current 0% crowd-implied probability for YES on a particular band is mainly a platform signal rather than a meteorological one: on Polymarket, the market is quoted as outcome probabilities, while Kalshi-style contracts are usually framed in cents, and Betfair or Smarkets-style books add exchange commission and often a different user base. In practical terms, this means the same weather risk can look cheaper or richer depending on whether you are reading implied probability, decimal-style pricing, or net-after-fee returns, and KYC access is also broader on regulated venues than on crypto-native ones. Historical Tokyo August data from JMA show that daily maxima commonly cluster in the low- to mid-30s, so a zero-price tail outcome would usually imply the market is leaning hard against an extreme reading rather than against a warm day itself.[12][13]

The main catalysts are the live temperature trend in Tokyo through the afternoon local time, any short-term forecast upgrades from the Japan Meteorological Agency, and whether cloud cover, sea breezes, or afternoon convection cap the peak before the highest reading is logged. Polymarket notes that revisions within the settlement window count until the first datapoint for the following date is published, so traders need to watch the exact publication timing on Wunderground as well as the local weather evolution; recent reporting has also highlighted Japan’s broader heat risk and record-setting conditions, which matters because persistent hot spells can nudge expectations upwards even when day-to-day variance remains high.[7][16]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We read Highest temperature in Tokyo on August 1? 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.

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.