Highest temperature in Wellington on July 20?

Platform comparison

Market context

Wellington’s highest temperature on 20 July 2026 is the real-world event determining this market’s outcome, with the settlement window closing at noon UTC on that date. The crowd currently assigns a 0% implied probability to the YES outcome, suggesting near-universal consensus that the temperature will fall outside the specified range. Historical mid-July highs at Wellington International Airport (NZWN) typically cluster between 6°C and 14°C, with 12°C emerging as the most frequent peak in comparable years, aligning with current forecast models that position 12°C as the leading expectation [1].

Traders should monitor MetService New Zealand’s daily maximum temperature releases and Wunderground’s hourly records for NZWN, as these are the official resolution sources [2]. A sharp south-south-westerly wind, currently recorded at 24 mph with temperatures near 15°C, could suppress daytime highs if it persists through the settlement window [3]. Contrarian value may exist if forecasts shift toward warmer air masses from the Tasman Sea, though current data heavily favours the 12°C outcome as the frontrunner, with 6°C or below holding negligible market support [1]. The consensus is firmly anchored on 12°C, leaving little room for deviation unless an unexpected weather system alters conditions.

Sources: 1 · 2 · 3

Methodology

We track Highest temperature in Wellington on July 20? 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

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 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.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.