Highest temperature in NYC on August 3?

Platform comparison

Market context

The key question is whether LaGuardia Airport posts a daily high in the **82–85°F** band, since that is where the Polymarket crowd is concentrated, while the market’s 0% YES price on your platform suggests traders there are treating a higher outcome as very unlikely. On Polymarket, the leading buckets are **82–83°F at 35%** and **84–85°F at 33%**, with the book describing prices as direct implied probabilities rather than decimal odds.[1] By contrast, Betfair and Smarkets typically present exchange-style prices in decimal format, so the same view is expressed as odds and back/lay spreads rather than a simple percentage; that matters on a one-day weather contract because small differences in fee structure and spread can move the effective breakeven level more than the headline number.

For context, New York City’s August highs often sit in the low-to-mid 80s, and recent guidance in the market narrative itself points to **82–85°F** for this date, which is consistent with a “middle of the range” outcome rather than an extreme.[1] A recent climate-monitor summary for nearby New York reporting sites shows a **maximum of 83°F** on 3 August in its historical-style table, reinforcing that the current probability stack is anchored around the low-80s rather than a heat-spike scenario.[7] That is why the market is not pricing the upper bands aggressively even though the city has seen heat-wave episodes this summer.[8]

The main catalyst is the actual observed high at **LaGuardia Airport Station** on 3 August, not a citywide average, so traders need to watch the hourly progression through the afternoon and whether any later reading edges the day into the next temperature bracket before the final Wunderground history entry is locked in.[2] Polymarket explicitly says revisions made before the first datapoint for the following date can still count, which makes the late-evening update sequence material for settlement timing.[1] On the platform side, access and friction differ: Kalshi-style event contracts are generally more compliance-heavy in the US, while Betfair and Smarkets may be unavailable or restricted depending on jurisdiction, so the same weather view can trade with different liquidity and fee drag across venues.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Highest temperature in NYC on August 3? 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 Kalshi Alternative UK, which mirrors the Polymarket order book at 0% fees.

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.

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. Kalshi Alternative UK 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. Kalshi Alternative UK 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.