Highest temperature in Wellington on August 17?

Platform comparison

Market context

Wellington International Airport's meteorological station will record ambient temperatures throughout 17 August 2026, with the highest reading determining which temperature band this market resolves into. The resolution hinges on the Daily Observations table in Weather Underground's historical data—a distinction that matters because summary high-low sections sometimes lag or aggregate differently than granular hourly records. For programmatic traders, this means building a scraper that polls the Daily Observations endpoint rather than relying on the summary card; Weather Underground's API documentation specifies how to access intraday readings, though the site's terms require checking current access policies before deployment.

Wellington's August sits at the tail end of the Southern Hemisphere's winter, with historical daily maxima typically ranging between 10–14°C. The 0% crowd probability suggests the market is either pricing in an unusually cold day or reflects low participation; comparing to August 2024 and 2023 data from NIWA (National Institute of Water and Atmospheric Research) would establish whether the current odds align with seasonal norms or signal genuine expectation of an outlier. Traders evaluating this market should cross-reference MetService forecasts released in early August 2026 and monitor any unusual pressure systems developing over the Tasman Sea in the preceding weeks—these drive Wellington's temperature swings more reliably than seasonal averages.

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.

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 Polymarket Review 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%.