Highest temperature in Wellington on August 19?

Platform comparison

Market context

On 19 August 2026, Wellington International Airport will record its highest temperature for that date, measured against historical daily observations data from Weather Underground. The market currently prices this outcome at 0% YES across all temperature bands, reflecting the settlement window's closure at midday UTC—well after the local observation period concludes in New Zealand's early evening. This timing constraint means traders are pricing based on information already observable or imminent, making the contract function as a retrospective settlement rather than a forward-looking wager.

Wellington's August temperatures typically range between 7°C and 13°C, with historical highs on 19 August clustering in the low-to-mid teens Celsius. The 0% probability across all bands suggests the market may be awaiting final Weather Underground data publication, or reflects thin liquidity in a niche regional weather contract. Comparable August markets for Wellington show similar compressed probabilities once the settlement window approaches, as conditional token holders await definitive readings from the airport station rather than speculating on meteorological outcomes days in advance.

Traders monitoring this contract should track Weather Underground's Daily Observations table publication timing, which typically updates within hours of the observation period closing. The resolution hinges entirely on that specific data source rather than summary figures, creating potential discrepancies if alternative weather services report different highs. Any delays in Wunderground's data feed could extend the settlement window, though the 12:00 UTC cutoff provides a hard deadline for resolution regardless of publication status.

Methodology

We track Highest temperature in Wellington on August 19? 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

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

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%.