Highest temperature in Wellington on August 18?

Platform comparison

Market context

Wellington’s 18 August temperature market is being driven by a cold, windy southerly setup rather than any warmth risk. The latest market snapshot points to a strong lean towards 12°C, with the competing 13°C outcome much less likely, while local forecast services have recently shown daytime highs around 8–11°C and unsettled conditions with showers and brisk southerlies. [4][8][12]

That makes the current 0% YES probability for the wider “highest temperature” framing look consistent with a low-ceiling day, especially given Wellington’s tendency for sharp maritime variability and the way southerly outbreaks can cap maxima well below seasonal norms. Comparable August setups in the city often resolve in the low double digits when a polar air mass is in place, so traders should treat any brief clearing or down-sloping wind as the main upside risk rather than a broad warm-up. [4][11][14]

The key catalysts are the live Weather Underground Daily Observations updates at Wellington Intl Airport, because that table, not the summary high/low strip, determines settlement. The main watchpoint is whether early morning showers give way to a slightly higher midday peak before the 12:00Z window closes; if the southerly flow holds, the market is leaning on a suppressed maximum, but any faster-than-expected clearing would be the only realistic route to a higher bracket. [5][4][8]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Political prediction markets differ structurally from sports betting: thinner liquidity, longer settlement windows, higher sensitivity to single news events. This page shows the live Polymarket quote for Highest temperature in Wellington on August 18? plus platform attributes for the three reference venues, so you can see at a glance where the deepest market for this question sits.

Resolution & payout

Political markets typically settle on official candidate or agency confirmation. Polymarket uses UMA Optimistic Oracle: a proposer posts the outcome with a bond, the two-hour window opens, then the smart contract pays USDC.

Kalshi settles USD via CFTC clearinghouse, with clearly defined resolution sources (e.g. AP race calls for elections). Betfair settles after the official outcome is registered with the league or agency. Manifold is play-money.

UK Frequently Asked Questions

How accurate are political prediction markets?

Historically more accurate than polls. Polymarket's Brier score on US 2024 elections was ~0.11 — better than 538 (~0.14) and every mainstream poll. Markets aggregate information with real skin in the game.

What resolution source is used for elections?

Polymarket defines the source per contract — usually Associated Press (AP Race Call), Reuters or the official electoral commission. The source is stated in contract details before the market opens.

Can prediction markets influence election outcomes?

Markets reflect expectations rather than create them. Studies show public-facing markets can anchor expectations, but don't influence the underlying outcome. Political markets are information, not advocacy.

How fast do political markets react to news?

High-liquidity markets move within seconds to minutes. A Trump tweet on the economy can shift the "Trump 2024" market 2-5 points before mainstream media has written anything.

Are UK election prediction markets available from the UK?

Yes. Betfair Exchange and Smarkets offer UKGC-regulated UK election markets (seat counts, party share, constituency results). Polymarket also lists UK election contracts with deeper global liquidity. Betfair winnings are typically tax-free for UK individuals; Polymarket profits are subject to HMRC CGT.