Highest temperature in Sao Paulo on June 30?

Platform comparison

Market context

The underlying event is the highest temperature recorded on 30 June 2026 at São Paulo-Guarulhos International Airport, measured in degrees Celsius. Long-term averages for June in São Paulo show daytime highs typically reaching 22°C, with extremes rarely exceeding 25°C, and the month’s highest recorded maximum so far in 2026 was 25.7°C on 22 June[1][5]. This historical context explains why the crowd-implied probability of a higher-than-expected range sits at 0%: the data strongly suggests no extreme heat spike is likely on the final day of the month[1][3].

Traders should monitor any late-month weather bulletins from Brazil’s national meteorological service (INMET) and real-time updates from Wunderground, the official resolution source, as even minor deviations in cloud cover or wind patterns could shift the peak temperature[5]. While a severe heat wave recently hit Rio de Janeiro with perceived temperatures of 62°C, such extremes are geographically isolated and not typical for São Paulo’s inland climate[2]. Platform comparisons reveal key divergences: Polymarket uses decimal odds and lower fees with minimal KYC, whereas Kalshi and Betfair rely on implied probability models, stricter identity verification, and higher fee structures, affecting liquidity and pricing efficiency on this specific weather market.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We read Highest temperature in Sao Paulo on June 30? 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

Polymarket settles via UMA Optimistic Oracle on Polygon. A proposer posts the outcome with a bond, the two-hour window runs, then the smart contract pays USDC.

Kalshi settles USD through the CFTC-regulated clearinghouse — the cleanest variant, with heavier KYC. Betfair Exchange settles in account currency (GBP/EUR), net of 2-5% commission. Smarkets follows the same model as Betfair with a lower default 2% commission.

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.

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. Kalshi Alternative UK 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.