Highest temperature in NYC on August 3?

Platform comparison

Market context

LaGuardia Airport’s highest reading on 3 August will determine this market, so the key question is whether the day tops out in the low- to mid-80s Fahrenheit or slips into the upper 80s if sunshine wins out. Polymarket’s current book has 82–83°F as the leading band at 35%, with 84–85°F close behind at 33%, while the market description notes that 82–85°F is the latest model-guidance cluster; the crowd-implied 0% YES price therefore looks like a platform or contract mismatch rather than a genuine belief that the temperature cannot land in a winning range.[1]

That pricing sits in a familiar late-summer pattern for New York: August highs often sit around the low 80s, but small changes in cloud cover, sea-breeze timing and thunderstorm coverage can move the airport reading by several degrees. The historical analogue from weather sites and climatology products is a city that can reach the low 80s on a normal August day, while station-specific airport data can run warmer or cooler than broader city forecasts.[5][14] On Betfair-style or Smarkets-style books, traders usually see decimal odds first, then convert to implied probability; on Polymarket and Kalshi, the quoted share price is already closer to an all-in probability, which makes the same forecast look cheaper or richer at a glance even before fees.

For catalysts, the main variables are the day’s terminal forecast updates, thunderstorm timing and whether any afternoon convection arrives early enough to cap the high before the settlement cutoff. A New York-area storm threat was flagged in local coverage on Monday, underscoring that cloud and rain risk can still matter for the final airport maximum if cells develop earlier than expected.[9] Platform mechanics also differ: Polymarket’s event notes say revisions are considered until the first datapoint for the following day is published, while competitors such as Kalshi, Betfair and Smarkets can differ on fee treatment, market wording and whether your account can participate at all, because KYC and jurisdictional access are not aligned across books.[1]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We read Highest temperature in NYC on August 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

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.

What about Smarkets as an alternative?

Smarkets is a UK betting exchange with a lower default commission (2%) than Betfair. Liquidity on political markets is below Polymarket, comparable to Kalshi. Geo-blocked in many jurisdictions.

Which platform is accessible globally?

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

Which platform supports Klarna/SOFORT?

Directly: none. Polymarket accepts only USDC on Polygon. Polymarket Alternative 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.