Highest temperature in Wellington on July 9?

Platform comparison

Market context

On 9 July 2026, Wellington International Airport will record its peak daytime temperature, a critical real-world datum for this prediction market. The crowd currently assigns a 0% probability to the "YES" outcome, implying near-universal consensus that the temperature will fall outside the specific range being bet on. This stark pricing suggests traders believe the day will be unusually cold or that the range is misaligned with historical norms.

Historical July highs in Wellington cluster tightly between 11°C and 14°C, with 14°C sitting at the centre of the long-term distribution[1][2]. Recent weather patterns show a cold southerly dropping temperatures to 9°C–10°C on 8 July, followed by a quick moderation on 9 July that should restore the maximum closer to the typical 11°C–12°C band[3]. Given this stability, the 0% implied probability appears contrarian; value may sit in betting against the consensus if the moderation is stronger than expected, pushing the high into the 12°C–13°C range where current odds are thin[1].

Traders should monitor the National Institute of Water and Atmospheric Research (NIWA) for updates on southerly wind persistence and cloud cover, which directly dictate daytime heating[7]. Any sudden shift in wind direction from southerly to westerly could trigger a rapid temperature spike, invalidating the current 0% pricing. While no specific weather announcement is pending, the dependency on wind moderation remains the primary catalyst; if the southerly lingers, the 11°C outcome becomes the favourite, whereas a swift westerly turn makes 12°C the underdog with hidden value[2][3].

Sources: 1 · 2 · 3 · 4 · 5

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.

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

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'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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Who Will Win trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.