Highest temperature in NYC on July 21?

Platform comparison

Market context

The highest temperature recorded at LaGuardia Airport on 21 July 2026 will determine the settlement range for this market. LaGuardia's weather station maintains continuous records throughout each day, with the peak temperature typically occurring in the afternoon hours during summer months. The settlement window closes at midday UTC on that date, meaning the final reading will capture the full diurnal cycle for New York City's primary airport weather station.

Historical July temperatures at LaGuardia show considerable year-to-year variation. The station has recorded July highs ranging from the mid-70s Fahrenheit to the low 90s over recent decades, with occasional excursions into the mid-90s during heat waves. The 30-year average high for late July sits around 84°F, though this masks significant variability driven by Atlantic weather patterns, tropical systems, and continental air mass positioning. Comparable markets on summer temperatures in the Northeast have typically seen probability mass distributed across multiple temperature bands rather than concentrated in a single outcome.

Traders should monitor seasonal forecasting models and Atlantic hurricane activity through early July 2026, as tropical systems or their remnants can substantially alter temperature trajectories. The National Weather Service's extended outlooks, typically issued 8–14 days in advance, will provide the most actionable guidance as the settlement date approaches. Urban heat island effects specific to the LaGuardia location and any documented changes to local infrastructure or measurement protocols could also influence outcomes relative to historical precedent.

Methodology

Political prediction markets differ structurally from sports betting: thinner liquidity, longer settlement windows, higher sensitivity to single news events. This page shows the live Polymarket quote for Highest temperature in NYC on July 21? plus platform attributes for the three reference venues, so you can see at a glance where the deepest market for this question sits.

Resolution & payout

For political markets the resolution source is decisive. Polymarket defines a concrete source per contract (e.g. AP, Reuters, official electoral commission) and uses the UMA Optimistic Oracle as the on-chain dispute mechanism. With a clearly defined outcome the USDC payout lands within minutes of the final confirmation.

FAQ

How accurate are political prediction markets?

Historically more accurate than polls. Polymarket's Brier score on US 2024 elections was ~0.11 — better than 538 (~0.14) and every mainstream poll. Markets aggregate information with real skin in the game.

Can prediction markets influence election outcomes?

Markets reflect expectations rather than create them. Studies show public-facing markets can anchor expectations, but don't influence the underlying outcome. Political markets are information, not advocacy.

How fast do political markets react to news?

High-liquidity markets move within seconds to minutes. A Trump tweet on the economy can shift the "Trump 2024" market 2-5 points before mainstream media has written anything.

Why do Polymarket and Kalshi differ on elections?

Kalshi must follow CFTC compliance — strict definitions, clear resolution sources, US citizens only with KYC. Polymarket operates globally without CFTC oversight — deeper liquidity, but also higher regulatory risk.

Which political events have the biggest volume?

US Presidential election, party nominations (DNC/RNC), Senate majorities, individual state outcomes (Pennsylvania, Michigan, Wisconsin), and major European elections. Peak markets reach $50-500M per event.