Highest temperature in NYC on June 9?

Platform comparison

Active sub-markets

Market context

New York City's peak temperature on 9 June 2026 will be recorded at LaGuardia Airport and settled against historical weather data from Weather Underground. The settlement window closes at midday UTC, meaning traders must account for the full diurnal cycle recorded at the station through the morning of 10 June local time. This is a straightforward meteorological event with no ambiguity in measurement methodology, though platform differences in odds presentation may obscure the actual probability distribution across competing books.

Historical June temperatures at LaGuardia cluster heavily between 75–88°F, with extremes rarely exceeding 92°F or dropping below 68°F. The 30-year median high for early June sits near 80°F. The 0% crowd probability currently displayed suggests either extreme confidence in a specific narrow range or liquidity concentration at particular price points rather than genuine certainty about the outcome. Kalshi's binary structure and Polymarket's fractional shares handle this differently: Kalshi typically offers discrete temperature brackets with decimal odds, whilst Polymarket's AMM-based pricing can create arbitrage opportunities when implied probabilities across ranges fail to sum to 100%.

Traders should monitor the National Weather Service's 8–10 day forecast issued around 1 June, which gains meaningful skill at that horizon. Atlantic high-pressure systems and tropical moisture patterns in early June materially shift outcomes; a Bermuda high would suppress temperatures, whilst a stalled frontal boundary could drive heat. Fee structures vary significantly—Kalshi charges per contract, whilst Polymarket's 2% taker fee applies uniformly, affecting edge calculations on tight ranges.

Methodology

We read Highest temperature in NYC on June 9? from four platform perspectives: Polymarket (on-chain CLOB), Kalshi (CFTC-regulated exchange), Betfair Exchange (sports book exchange), Smarkets (peer-to-peer betting exchange). Polymarket's live quote comes directly from the Polygon order book; the other three are listed with their platform attributes — fees, KYC, settlement currency, payment options — because a 1:1 contract comparison without API access would be guesswork.

Resolution & payout

Polymarket settles via UMA Optimistic Oracle on Polygon. A proposer posts the outcome with a bond, the two-hour window runs, then the smart contract pays USDC.

Kalshi settles USD through the CFTC-regulated clearinghouse — the cleanest variant, with heavier KYC. Betfair Exchange settles in account currency (GBP/EUR), net of 2-5% commission. Smarkets follows the same model as Betfair with a lower default 2% commission.

FAQ

Where can I trade this market with the lowest fees?

On Kalshi Alternative UK, which mirrors the Polymarket order book at 0% fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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 Kalshi Alternative UK?

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

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.