Highest temperature in Sao Paulo on July 9?

Platform comparison

Market context

On 9 July 2026, the real-world event determining this market is the highest temperature recorded at São Paulo-Guarulhos International Airport, measured in degrees Celsius. A YES share in this prediction market pays out if the official reading matches the specific temperature range the contract defines, while a NO share wins if it does not. The crowd currently assigns a 0% probability to YES, implying traders believe the temperature will not hit the target threshold.

Historically, July is São Paulo’s coolest month, with average highs between 11°C and 22°C, and daily peaks rarely exceeding 22°C in recent years[7]. While Brazil has experienced extreme heatwaves, such as the record 35.9°C in December 2024 or perceived temperatures of 62.3°C in Rio during a 2024 heatwave, these are outliers not typical of mid-winter in São Paulo[3][6]. The current 0% probability aligns with the seasonal norm that July highs cluster around 18–21°C, making a 23°C reading highly improbable unless an unusual warm anomaly occurs[1].

Traders should monitor the daily weather forecast for São Paulo released by AccuWeather, which projects July 2026 highs between 66°F and 81°F (roughly 19°C to 27°C), and watch for any sudden shifts in cloud cover or wind patterns that could elevate temperatures[1]. The primary catalyst is the official Wunderground report for SBGR on 9 July, which will settle the market; no political announcements or schedules influence this outcome, as it depends solely on atmospheric conditions[10]. If forecasts show a sustained warm spell pushing highs toward 24°C, the probability may shift, but current data suggests temperatures will remain well below the 23°C threshold.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

FAQ

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Prediction Market UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.