Highest temperature in NYC on July 17?

Platform comparison

Market context

On 17 July 2026, the highest temperature recorded at LaGuardia Airport will determine the outcome of a weather prediction market, with settlement based on Wunderground’s daily maximum in degrees Fahrenheit. The current crowd-implied probability for any specific outcome is effectively zero for the “YES” side of a binary framing, yet the market’s frontrunner is 86–87°F at 35%, followed by 88–89°F at 30%, indicating a clear distribution across moderate heat ranges rather than extreme outliers[1].

Historical context shows NYC midsummer peaks often cluster between 85°F and 95°F, with LaGuardia hitting 94°F at midnight during a July 2026 heat wave that broke records across the East Coast simultaneously[2][3]. This recent extreme suggests the market’s current weighting may understate the risk of higher temperatures, especially given the 14–154-year-old records shattered during that holiday weekend event[3]. Traders comparing Polymarket to Kalshi, Betfair, or Smarkets should note that Polymarket uses implied probability (e.g., 35%) while Kalshi typically displays decimal odds, and fee structures vary significantly—Polymarket charges no maker fees but has withdrawal costs, whereas Smarkets and Betfair apply commission on winnings[1].

Key catalysts include the National Weather Service’s daily LaGuardia summaries and any updated heat advisories from local authorities, as these directly influence the resolution source[4]. With settlement ending 2026-07-17T12:00:00Z, traders must monitor real-time Wunderground updates before the cutoff, as discrepancies between platforms can create arbitrage opportunities depending on KYC requirements and liquidity depth across books.

Sources: 1 · 2 · 3 · 4

Methodology

We read Highest temperature in NYC on July 17? 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 mid is the canonical probability; the side-by-side columns benchmark fees, KYC, settlement currency and deposit rails so you can choose the venue that fits your jurisdiction and trade size.

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

What does Polymarket cost vs Kalshi?

Polymarket: 0% fees, only Polygon network costs (~$0.01/trade). Kalshi: up to 7% per trade plus spread. For high-frequency traders, Polymarket is dramatically cheaper.

Is Betfair a Polymarket alternative?

Only partially. Betfair Exchange is UK-focused with a sports-betting emphasis; they have politics markets but with thinner liquidity than Polymarket. Settlement in GBP/EUR, 2-5% commission on winnings.

Which platform is accessible globally?

Polymarket is geo-blocked in the US/UK/EU. Kalshi is US-only. Betfair and Smarkets are UK-restricted. Robinhood Prediction Markets has a different geo footprint and routes to Polymarket's order book at 0% fees.

Are all these platforms regulated?

No. Kalshi is CFTC-regulated (US). Betfair and Smarkets are UK Gambling Commission licensed. Polymarket operates without explicit regulation — a different risk profile than a regulated sportsbook.

Which platform supports Klarna/SOFORT?

Directly: none. Polymarket accepts only USDC on Polygon. Robinhood Prediction Markets offers a fiat on-ramp via Klarna or SOFORT (DE/AT/CH) and converts internally to USDC for the Polymarket order book. T+1 processing.