Highest temperature in Wellington on August 18?

Platform comparison

Market context

Wellington’s 18 August temperature market is priced like a hard no, with the crowd at 0% YES and the relevant benchmark being the highest reading in Weather Underground’s Daily Observations table before the 12:00 UTC settlement cut-off. The favourite is therefore the sub-threshold outcome, and the market is effectively asking whether Wellington Airport can break out of a cool late-winter profile by midday.

Historically, August in Wellington is usually mild rather than warm: long-run climate norms put daytime highs around 12°C, with NIWA’s June-to-August outlook for the wider Wellington region calling temperatures most likely to be near average. That frames the current price as a consensus view that the airport will struggle to post an unusually high intraday maximum, especially with the settlement window ending at local morning time. A contrarian value case would need an early spike from a dry, sunny break in cloud or a wind shift that limits marine cooling; otherwise, the base rate favours the under.

The catalyst to watch is the actual airport observation sequence rather than headline app forecasts, because the market settles off the Daily Observations table. The key dependency is whether the morning develops enough sun and slack wind to lift the thermometer before noon UTC; otherwise, the highest reading may be set early and remain low. Recent Wellington guidance has shown cool, breezy conditions around 9–10°C in the daytime band, which supports the underdog framing for any higher-temperature band and leaves only a narrow weather-window for a surprise upside print.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Wellington on August 18? 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

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

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 Who Will Win 2026. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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 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.