Highest temperature in Wellington on July 9?

Platform comparison

Market context

Wellington’s July 9, 2026, is expected to see a high temperature near 11°C at the Wellington International Airport Station, with the market currently pricing 11°C as the frontrunner at 65% probability, while 10°C holds 18% [1]. This on-chain contract, settled in USDC on Polygon via conditional tokens, reflects a collective view that the day will fall within the climatological centre of Wellington’s July range, not an outlier heat event [2]. The current 0% YES probability for the “highest temperature” outcome likely refers to a specific, higher temperature range not yet defined in the market’s resolution tiers, making the 11°C outcome the most probable settlement.

Historically, Wellington’s July highs rarely exceed 57°F (13.9°C), with daily averages hovering around 53°F (11.7°C), and the lowest average high occurring on July 12 [6]. While extreme records exist—such as Kelburn’s all-time maximum of 30.3°C (86.5°F) recorded recently—the airport station typically registers cooler readings due to its coastal, elevated position [3][8]. This pattern suggests that 11°C is a statistically grounded expectation, not a speculative guess, and aligns with decades of observed data from NIWA and AccuWeather [3][4].

Traders should monitor daily weather bulletins from NIWA and the Wellington Regional Council for any sudden shifts in wind patterns or cloud cover, which can rapidly alter temperature outcomes [3]. A recent NIWA report on heatwave numbers highlights that even minor atmospheric changes can push temperatures above or below the 11°C threshold, making real-time data critical [3]. No major announcements are scheduled, but the settlement window ending 2026-07-09T12:00:00Z means final Wunderground data will be the sole resolution source, with no room for reinterpretation [1].

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

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 PolyGram. 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'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.