Highest temperature in Sao Paulo on June 30?

Platform comparison

Market context

The highest temperature recorded at São Paulo-Guarulhos International Airport on 30 June 2026 is the real-world event this market resolves, with the current crowd-implied probability for a "YES" outcome sitting at 0%. On Polymarket, this contract is priced today with the frontrunner outcome being 27°C at 99% probability, while the next closest outcome, 28°C, holds only 7% [1]. This pricing reflects the on-chain mechanics of USDC on the Polygon network, where conditional tokens allow traders to bet on specific temperature ranges without exposing themselves to the underlying event’s abstract uncertainty.

Historical data frames how to interpret this near-certain 99% probability for 27°C. Daily high temperatures in São Paulo during June typically hover around 72°F (22.2°C), rarely falling below 63°F (17.8°C) or exceeding 79°F (26.1°C) [3]. However, recent forecasts for June 2026 suggest daily highs ranging from 73°F to 84°F (22.8°C to 28.9°C), with an average high of 80°F (26.7°C) [5]. The market’s confidence in 27°C aligns with this upper end of the historical range, whereas the previous day’s market, 29 June, showed a 100% probability for 28°C, indicating a slight cooling trend is expected [2].

Traders should monitor the daily weather updates from Wunderground, the official resolution source, as well as any sudden shifts in regional cloud cover or wind patterns that could depress temperatures below the 27°C threshold. While no specific announcements are pending, the dependency on real-time data from the airport station means that any unexpected precipitation or frontal systems could alter the outcome. The average daily solar energy in São Paulo remains constant at 3.8 kWh throughout June, suggesting stable heating conditions unless disrupted by weather anomalies [3].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Sao Paulo on June 30? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to PolyGram, which mirrors the Polymarket order book at 0% fees.

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 PolyGram. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like PolyGram 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.