Highest temperature in NYC on July 4?

Platform comparison

Market context

New York City is currently experiencing an intense heatwave, with LaGuardia Airport recording its warmest midnight temperature ever at 94°F, breaking the 2013 record of 93°F[1][3]. This extreme thermal event frames the current 0% crowd-implied probability for the highest temperature on 4 July 2026, suggesting traders view a record-breaking peak as statistically improbable despite the lingering heat. Historical data confirms LaGuardia’s all-time high reached 107°F on 3 July 1966, indicating that while extreme peaks are possible, they are rare anomalies rather than seasonal norms[9].

Traders should monitor the National Weather Service’s daily climatological updates and AccuWeather’s July 2026 forecast, which predicts daily highs between 81°F and 99°F with overnight lows of 68°F to 83°F[2][5]. The divergence between platforms like Polymarket, which uses decimal odds, and Kalshi or Betfair, which rely on implied probability, becomes critical here; fee structures and KYC requirements also vary significantly, affecting liquidity for this specific weather contract. Recent reports from FOX Weather highlight that the heat has lingered, with temperatures even surpassing Phoenix’s 101°F record at 104°F, underscoring the volatility traders must anticipate[1][8].

The settlement window ends on 4 July 2026 at 12:00 UTC, with resolution sourced from Wunderground’s highest recorded temperature for LaGuardia Airport[1]. As platforms diverge on fee models and identity verification, the choice between Polymarket’s open access and Kalshi’s regulated environment will influence how quickly the market adjusts to new temperature data. The current heatwave’s persistence, confirmed by multiple sources, means traders must weigh the likelihood of a 100°F+ peak against the historical rarity of such extremes[3][7].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Highest temperature in NYC on July 4? specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. The live probability is the Polymarket mid; the comparison columns summarise each venue's fee structure, KYC, settlement currency and payment rails. Every CTA routes to Robinhood Prediction Markets, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Settlement is the biggest difference between the four platforms: Polymarket on-chain in USDC (instant), Kalshi USD via CFTC (T+1), Betfair and Smarkets in local currency via bank withdrawal (T+1 to T+3). On-chain settlement clears in minutes — the fastest payout path of the four.

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.

Which platform has the deepest liquidity?

Polymarket — by a wide margin. Top markets reach $50-500M volume, Kalshi ~$200M cumulative, Betfair similar. Deeper liquidity means your trade moves the quote less.

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.