Highest temperature in NYC on July 12?

Platform comparison

Market context

New York City is baking under an intense summer heatwave on 12 July 2026, with a strong high-pressure system dominating the region and driving hazardous conditions across the Northeast. Forecasts indicate afternoon highs around 94°F in the city, with humidity near 75% pushing the heat index to approximately 105°F, while LaGuardia Airport could record similar or slightly elevated temperatures due to its coastal exposure [1].

Historically, July in New York sees average highs of 84°F, yet recent extremes have shattered norms, including a 100°F record on 2 July 2026 during the 2026 North American heat wave [2][5]. The current crowd-implied probability of 0% for any specific high-temperature range appears disconnected from this reality, as the atmosphere remains primed for temperatures well above the seasonal mean, with LaGuardia previously hitting 102°F during a record-setting heat event [6].

Traders should monitor real-time updates from Wunderground and the National Weather Service, as the settlement relies explicitly on the highest temperature recorded at LaGuardia Airport Station [1]. The heat dome building over the northern US is expected to persist through 12–14 July, creating a direct dependency on whether the high-pressure system intensifies or begins to weaken before the settlement window closes at 12:00 UTC [9]. On-chain mechanics on Polygon mean USDC positions will settle automatically once the Wunderground data confirms the final range, with conditional tokens reflecting the updated probability as the day progresses.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Kalshi UK 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.