Highest temperature in Atlanta on August 5?

Platform comparison

Market context

Atlanta’s high temperature on 5 August is settled from the single hottest reading at Hartsfield-Jackson, so the relevant question is not the forecast peak for the city generally but the day’s airport maximum in Fahrenheit. In late summer, Atlanta often sits around the upper 80s to low 90s, and the market’s 0% YES print implies the crowd is effectively ruling out a very warm but not extreme outcome and loading up on the higher bands instead.[2][13]

That pricing is easier to read against recent Georgia heat than against any one-off city headline. Atlanta has reached 100°F in recent summers, including the 2025 climate summary from the NWS Atlanta office, which shows a 100°F maximum at the Atlanta climate site last summer; that places a mid-80s to upper-80s airport high well inside normal heat rather than a tail event.[12] By contrast, if clouds or storms clip the afternoon, a result in the low 80s becomes plausible, and the contract’s banding means a one-degree difference can move the payout into a different bracket.[1][7]

The main catalysts are the forecast track for afternoon convection, the strength of the regional heat ridge, and any shift in local aviation weather affecting the airport station specifically. Wunderground’s historical page for KATL is the settlement source, so traders should watch the station-level daily high rather than downtown Atlanta forecasts or a broader metro outlook.[3] On the crypto side, this is a USDC-settled binary-style event, so BTC and ETH direction matter mainly through risk appetite and liquidity: tighter funding or sharper spot moves can change how aggressively traders lean into the higher temperature bands, but the contract itself will still resolve purely to the airport reading.[1]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically this overview focuses on on-chain pricing: Polymarket's live mid comes from the Polygon conditional-token order book and settles automatically in USDC. The other three venues — Kalshi, Betfair, Manifold — sit alongside as off-chain reference points so you can see how the contract translates across regulatory and settlement regimes.

Resolution & payout

Settlement is on-chain via UMA Optimistic Oracle. A proposer posts the outcome with a bond, a two-hour dispute window opens, then the smart contract lifts winning conditional tokens to 1 USDC and sends payments to holders' wallets automatically. No withdrawal fees beyond Polygon gas.

Off-chain venues (Kalshi, Betfair, Smarkets) settle in local fiat through bank-side clearing — faster than SWIFT, slower than on-chain. Manifold pays no real cash.

UK Frequently Asked Questions

What are crypto prediction markets?

Crypto prediction markets are on-chain smart contracts where you buy YES or NO shares on a future crypto event (e.g. "BTC above $100k by year-end"). The market price between 0¢ and 100¢ is the implied probability.

Why USDC and not ETH or USDT?

USDC is the Polygon standard — audited reserves (Circle, monthly attestation), deepest order book, low gas costs. ETH volatility would distort probability quotes; USDT has thinner Polygon liquidity than USDC.

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%.