Highest temperature in NYC on July 3?

Platform comparison

Market context

On 3 July 2026, LaGuardia Airport in New York City will record its highest daily temperature, a real-world event that determines the outcome of a prediction market currently implying zero probability for any temperature above 100°F. This near-certain dismissal of extreme heat contrasts sharply with recent historical data: on 2 July 2026, LaGuardia hit 104°F, surpassing its 1966 daily high of 101°F, while Newark and LaGuardia previously set all-time July 3 records of 105°F and 107°F respectively in that same year[4][7]. The current 0% implied probability suggests traders are betting on a rapid cooldown, yet the immediate precedent of 102–103°F on 2 July[1] and the warmest midnight ever recorded at 94°F just days prior[2][3] indicate that extreme heat remains a persistent, not anomalous, feature of early July weather in the region.

Traders should monitor the National Weather Service’s heat advisories and the scheduled release of the 3 July morning forecast, as a persistent high-pressure system could sustain temperatures near the 100°F threshold. Recent coverage from Yahoo News highlights the danger of record-breaking heat waves in New York and New Jersey, noting that multiple records for 3 July remain unbroken since 1966, including the 107°F mark at LaGuardia[7]. When comparing platforms, Polymarket’s decimal odds format may obscure the nuance of a 0% implied probability that Kalshi’s probability-based interface clarifies, while Betfair’s fee structure and Smarkets’ lower commissions diverge significantly on liquidity costs for such binary outcomes. Additionally, Kalshi’s strict KYC requirements contrast with Polymarket’s broader global reach, affecting who can access this specific market and how deeply the crowd-implied probability reflects genuine sentiment versus platform-specific bias.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We read Highest temperature in NYC on July 3? 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

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

Polymarket vs Kalshi — which is better?

Depends on your location. Kalshi is CFTC-regulated, US-only with full KYC. Polymarket is global, on-chain, no KYC up to $1,500. Polymarket has ~10x higher liquidity but higher regulatory risk.

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.