Highest temperature in Sao Paulo on June 30?

Platform comparison

Market context

The underlying real-world event is the highest temperature recorded at São Paulo-Guarulhos International Airport on 30 June 2026, measured in degrees Celsius. Long-term averages for June in São Paulo show daytime highs typically reaching 25°C, with a recorded maximum of 25.7°C on 22 June 2026[1][5]. Historical data confirms that June is a cool month in the region, with average highs rarely exceeding 26°C and frequent rainfall averaging 71mm per month[1][3]. The current crowd-implied probability of 0% for any temperature above the settlement threshold aligns with these patterns, as extreme heat events are exceptionally rare in São Paulo during this period[1][7].

Traders should monitor weather forecasts for unusual rainfall patterns in Brazil’s Center-South region, which models have flagged as above normal since early 2026[2]. A recent YouTube report dated 30 June 2026 highlights persistent cloud cover and precipitation that will likely suppress daytime temperatures further[2]. On-chain, the contract settles via conditional tokens on Polygon, with USDC payouts determined by Wunderground’s official daily high for SBGR[1]. No temperature spikes are expected given the prevailing wet conditions, reinforcing the market’s 0% YES pricing. The settlement window closes at 12:00 UTC on 30 June 2026, locking in the final resolution based on verified data[1].

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

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

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.

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.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Polymarket Scam? trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

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.