Highest temperature in NYC on August 9?

Platform comparison

Market context

The event is whether LaGuardia Airport’s highest recorded temperature on 9 August 2026 lands inside the market’s winning range, using Weather Underground’s **Daily Observations** table rather than the summary high/low box. In practical terms, that makes this a station-specific afternoon temperature market, not a citywide feeling-of-the-day trade, and the current crowd price of **0% YES** is inconsistent with the market text if the contract is already being quoted as resolved against an observed outcome on the same date. WeatherSpark’s live history page showed KLGA at **88.0°F** with a **6-hour high of 89.1°F** in the latest report on 9 August, while AccuWeather’s monthly page pointed to a **90°F** high for New York on that date, which supports the idea that the outcome likely sat in the upper-80s to low-90s band rather than a sharp outlier.[1][2]

That framing matters when comparing books. Polymarket quotes the contract in implied probability, so a 73% price is read as a market-implied chance, while Kalshi-style markets and Betfair/Smarkets-style exchange books are more often assessed through decimal odds and net-of-fee execution; on short-dated weather contracts, those differences can make similar views look less or more expensive after commission and spread. Here, the public Polymarket page showed **90–91°F** as the leading bucket at **73%**, with **92–93°F** next at **20%**, which is a useful benchmark even if another venue’s fee and KYC rules make the trade effectively less accessible or less liquid.[4][6]

For catalysts, the main driver is the late-day temperature evolution at LaGuardia, plus any update in the National Weather Service’s New York briefing or terminal forecasts before the settlement cut-off; once the final observation prints, the market should be mechanically pinned by the Wunderground station record rather than by broader NYC headlines.[10][13] The important trader-specific distinction is that Robinhood’s product, if offered to the user, will typically feel closer to a regulated retail event contract, while Polymarket’s open market pricing can move faster around weather updates, and Betfair/Smarkets may be constrained by jurisdiction and account verification even when the underlying view is identical.[6]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We read Highest temperature in NYC on August 9? 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.

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.

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.