Highest temperature in Sao Paulo on May 22?

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Market context

On 22 May 2026, the highest temperature recorded at São Paulo-Guarulhos International Airport will fall into one of several defined ranges. This market settles against historical weather data from Wunderground, which archives hourly observations at Brazil's busiest airport station. The settlement window closes at 12:00 UTC on that date, meaning the final temperature reading must be confirmed by Wunderground's historical records before resolution occurs.

May in São Paulo typically sees autumn conditions in the Southern Hemisphere, with average highs around 24–26°C. Historical data from the same station shows May temperatures rarely exceed 30°C; the 0% crowd probability suggests traders are pricing in an expectation well below the upper ranges offered. Comparable May days at Guarulhos over the past decade have peaked between 22–28°C, with extreme outliers above 30°C occurring in fewer than 5% of cases. The current market positioning reflects this seasonal baseline and the relative rarity of heat spikes during autumn months.

From a regulatory standpoint, this weather market operates under different compliance frameworks depending on trader location. The German GlüStV (gambling licensing authority) treats prediction markets as wagering products requiring operator licensing; UK traders face no direct KYC requirement for positions under £1,500, though operators must still verify identity at higher stakes. US CFTC oversight applies only if the operator is US-domiciled or targets US customers directly. Traders should confirm their jurisdiction's stance before entry, as tax reporting obligations vary significantly between EU member states and the UK post-Brexit framework.

Methodology

This page reviews Highest temperature in Sao Paulo on May 22? across five venues. We show live odds for Polymarket-based markets (sourced from the Polygon order book); for other venues we list platform attributes, since the comparable contracts are not exposed via a public API on every venue. Every CTA points at PolyGram — the application we operate, where you trade directly against the Polymarket order book at 0% fees.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

FAQ

Where can I trade this market with the lowest fees?

On PolyGram, which mirrors the Polymarket order book at 0% fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

PolyGram is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, PolyGram triggers a quick verification flow that finishes in 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.