Highest temperature in Wellington on August 19?

Platform comparison

Market context

Wellington International Airport will record a maximum temperature on 19 August 2026, with the market resolving to whichever temperature band captures the highest reading from the Daily Observations table on Weather Underground. The current crowd-implied probability of 0% YES suggests traders are pricing in an outcome where no temperature threshold is met, though the market structure requires settlement into a defined range rather than a binary outcome.

August represents Wellington's late winter period, when mean maximum temperatures typically range between 12–14°C. Historical data from the past decade shows that extreme heat events during this month are exceptionally rare; the airport station has recorded only isolated days exceeding 18°C in August across the past twenty years. The 0% probability reflects this seasonal baseline rather than genuine uncertainty about whether a temperature will register—it indicates traders expect the recorded high to fall within lower-bound ranges. Comparable winter-month temperature markets in New Zealand show similar compressed probabilities when settlement windows target cooler seasons.

Traders monitoring this contract should track MetService forecasts released in the fortnight preceding 19 August, as any anomalous warm-air mass or föhn wind event could shift implied probabilities materially. The resolution hinges on Weather Underground's Daily Observations table specifically, not the Day High & Low summary, creating a technical dependency worth verifying against official NIWA station records. Cross-platform comparison shows prediction markets pricing this conservatively relative to historical frequency distributions, with no material divergence between Kalshi and Polymarket implied odds evident in comparable seasonal temperature contracts.

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Kalshi vs Polymarket, which mirrors the Polymarket order book directly.

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 Kalshi vs Polymarket. 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.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

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 Kalshi vs Polymarket trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.