Highest temperature in Sao Paulo on August 7?

Platform comparison

Market context

The immediate change in the last 24–48 hours is that the late-winter setup has stayed firmly in place: forecast guidance for São Paulo points to a dry, sunny day with a high around 25°C, while market pricing still clusters around 25–27°C rather than anything extreme.[7][2][1] For a market settled on the highest reading at São Paulo–Guarulhos on the day, that matters because the airport station can run a touch cooler or warmer than city-centre forecasts, but it still usually tracks a modest August daytime range rather than a sharp heat spike.[6][12]

Historically, August in São Paulo is a mild winter month, with average highs around 23–25°C and lows in the low-to-mid teens Celsius.[6][8][12] That makes the current 0% YES probability on an outsized temperature band easier to understand: the distribution is anchored near normal conditions, and the published trader consensus is already concentrated in the mid-20s Celsius.[2] In practical terms, the market is reading like a “temperature near average” event unless the airport station prints a late-afternoon overshoot above the forecast high.[2][7]

The main catalysts to watch are the day’s actual observations from Weather Underground’s Daily Observations table, because the market resolves on that source rather than the summary high/low display, and revisions remain possible until the first datapoint for the following date is published.[2] That means traders should focus on the timing of the station’s afternoon peak, any late updates to the airport feed, and whether local cloud cover or a stronger-than-expected sun angle nudges the maximum into the next Celsius band.[2][7] Forecast services for the day still point to full sun and no rain, which reduces the odds of a suppressed high, but does not remove the chance of a one-degree miss on the settlement band.[1][7][9]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Sao Paulo on August 7? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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.

UK Frequently Asked Questions

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.

Is Polymarket legal in the UK?

Polymarket is accessible to UK traders but is not UKGC-licensed. It operates under US CFTC jurisdiction. UK residents face no domestic legal prohibition on using it, but UKGC consumer protections do not apply. For UKGC-regulated alternatives, Betfair Exchange and Smarkets offer similar prediction-style markets.

Do I pay tax on prediction market profits in the UK?

UKGC-licensed platform profits (Betfair, Smarkets) are typically tax-free gambling winnings for UK individuals. Polymarket profits involve USDC crypto transactions, which HMRC treats as Capital Gains Tax events. Keep full transaction records and report via Self Assessment if gains exceed £3,000 per tax year.

How do I deposit on Polymarket from the UK?

UK traders typically fund Polymarket via Coinbase UK, Kraken or Revolut — buying USDC with GBP and transferring to a Polygon-compatible wallet (MetaMask, Coinbase Wallet). Polymarket's onboarding walks you through the bridging process. Typical GBP-to-USDC conversion costs 0.5–1%.