Highest temperature in NYC on August 18?

Platform comparison

Market context

New York City's maximum temperature on 18 August 2026 will be recorded at LaGuardia Airport Station and resolved against Weather Underground's Daily Observations table rather than summary figures. The current crowd-implied probability of 1% suggests traders assess an extremely low likelihood of the highest temperature falling into whichever range this market tracks—typically the uppermost bracket in a tiered resolution structure.

August temperatures at LaGuardia historically peak in the low-to-mid 80s Fahrenheit, with daily highs rarely exceeding 90°F during the month. The 30-year average maximum for mid-August sits around 82°F. Extreme heat days pushing above 95°F occur roughly once every five to ten years in New York during summer. The 1% probability reflects the rarity of sustained heat waves coinciding with this specific date; traders are pricing in a scenario where atmospheric conditions would need to align unusually—persistent high pressure, low cloud cover, and southwesterly flow—to drive temperatures into the uppermost resolution brackets.

The National Weather Service's seasonal forecasting and any Atlantic hurricane activity in early August could influence late-summer heat patterns, though such predictions remain inherently uncertain two years ahead. Traders monitoring this contract should track spring and early-summer 2026 climate patterns for signals of whether the Atlantic basin is primed for anomalous warmth propagation inland. The resolution methodology's reliance on Weather Underground's Daily Observations table rather than National Weather Service summaries introduces a minor data-source dependency; historical discrepancies between platforms are rare but possible during extreme weather events.

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to PolyGram, which mirrors the Polymarket order book directly.

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.

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.

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 PolyGram trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.