Highest temperature in Wellington on May 25?

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Active sub-markets

Market context

On 25 May 2026, Wellington International Airport will record a daily maximum temperature in Celsius, with the actual reading determining which range bracket resolves as correct. The settlement window closes at midday UTC, allowing for finalisation of the day's peak once observations are complete. Current crowd-implied probability sits at 0%, suggesting either extreme confidence in a particular outcome or insufficient liquidity across the available ranges.

Wellington's May climate sits firmly in autumn, with historical daily maxima typically ranging between 12–16°C during this period. The city's exposed location on Cook Strait produces volatile weather patterns; southerly flows can drive temperatures below 10°C within hours, whilst nor'westerly föhn conditions occasionally push readings into the low 20s. Comparable May days from the past decade show the airport station rarely exceeds 18°C, with sub-10°C maxima occurring roughly one year in three. The 0% probability reading suggests traders may be anchored to the coldest available bracket, though this warrants scrutiny against seasonal norms.

The New Zealand MetService issues extended forecasts five to seven days ahead, with updates typically published by 4 p.m. local time. Traders should monitor the official forecast issued around 19 May for atmospheric pattern signals—specifically whether a high-pressure system or low-pressure trough dominates the South Island during late May. Sea-surface temperatures around Cook Strait remain a secondary driver; cooler-than-average waters suppress daytime heating. Historical data from Wunderground's Wellington station provides the definitive settlement source, with no adjustments or interpolation applied to recorded observations.

Methodology

We track Highest temperature in Wellington on May 25? on the five venues with material liquidity for prediction markets. Live odds come from the Polymarket Polygon order book — the only source that ships real-time data under an open licence. For Kalshi, Betfair and Manifold we list platform attributes (fee, KYC, settlement, payment) instead of fabricated odds, because their APIs use non-comparable contract definitions.

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

Is this market available outside the US?

PolyGram is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

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 it cost to trade on PolyGram?

Zero. PolyGram routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, PolyGram triggers a quick verification flow that finishes in minutes.