Highest temperature in Houston on August 3?

Platform comparison

Market context

Houston’s August heat is measured at William P. Hobby Airport, with the contract settling off the final Weather Underground daily high once the next day’s first observation is published. For a programme that trades this kind of event mechanically, the key input is not the citywide feel but the station-level maximum, so any model should ingest the archived daily table for KHOU and wait for the update that closes out the day’s observations.[1]

A 0% crowd-implied price reads as an extreme, but the historical frame for Houston makes that less about impossibility than about how narrowly the market is defining the outcome. August in Houston is typically hot, and the city’s airport records include repeated 90s and occasional extremes well above that, with Hobby Airport itself hitting 91°F during an earlier 2026 heat spell and Houston’s broader airport climate record showing 109°F as an all-time high at the region’s main stations.[10][16][18] For a power-user, that means the question is whether the specific 3 August 2026 daily high at KHOU ever gets into the upper bands, not whether Houston is generally warm.

The main catalysts to watch are the day’s forecast evolution, cloud cover, rain chances, and any late-afternoon sea-breeze or thunderstorm timing that suppresses the high before the station’s daily maximum is locked in. Recent Houston coverage has pointed to a typical hot, mostly sunny summer pattern with low rain chances, though local forecasts can still shift quickly when storms build later in the day.[4][17] Programmatically, traders usually map this to hourly forecast feeds, compare ensemble highs against station history, and set conditional orders around thresholds where a one- or two-degree move changes the settlement bucket.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Kalshi Fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Kalshi Fees trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.