Highest temperature in London on July 16?

Platform comparison

Market context

London City Airport is tracking a mostly cloudy, very warm day with a forecast high of 86°F (30°C) for 16 July, yet the market currently assigns a 0% probability to any outcome implying extreme heat, creating a stark divergence between the immediate forecast and crowd pricing. This 0% YES figure likely reflects a misunderstanding of the settlement mechanics or a temporary liquidity gap, as the current frontrunner on the broader exchange is 28°C at 54%, with 29°C holding 30% [3]. The probability is not zero in a vacuum; it is an artifact of the specific market’s current state rather than a reflection of meteorological impossibility.

Historical July data for London City Airport typically sees highs between 20°C and 28°C, with the 2026 monthly forecast projecting daily highs ranging from 72°F to 84°F (22°C–29°C) [1]. The current reading of 73°F (23°C) at 11:20 AM on 15 July suggests the day is warming into the expected range, making outcomes below 28°C plausible but not guaranteed [2]. Traders should note that 28°C aligns with the upper end of the typical historical band, while 30°C would represent a significant outlier for this station, though the forecast explicitly flags "very warm" conditions for today [8].

The primary catalyst to watch is the actual hourly temperature update from Wunderground, which serves as the definitive resolution source for this market [3]. Traders must monitor the 12:00 UTC settlement window closely, as the market will resolve to the specific Celsius range containing the day’s peak temperature recorded at EGLC. Any sudden shift in cloud cover or wind direction from the current gentle NE breeze could alter the peak, but the forecast of 86°F suggests the temperature will likely breach the 28°C threshold if the "very warm" descriptor holds through the afternoon [8].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in London on July 16? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Prediction Today, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

FAQ

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.

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 fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

Do I need to KYC for this market?

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

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.