Highest temperature in Sao Paulo on June 30?

Platform comparison

Market context

The underlying event is the daily peak temperature at São Paulo-Guarulhos International Airport on 30 June 2026, a date historically marked by cool, dry winter conditions in Brazil. Long-term averages for June in São Paulo show daytime maximums around 22°C, with typical highs rarely exceeding 25°C and overnight lows falling to 16°C[1]. The warmest 10-day period in mid-June 2026 recorded highs averaging just 16.7°C, while the highest maximum temperature observed so far this month was 25.7°C on 22 June[2][4]. Given that the settlement window ends at 12:00 UTC on 30 June, and historical data indicates no June day in recent years has breached 30°C, the current 0% crowd-implied probability for a “YES” outcome (implying a temperature above a high threshold) aligns with robust climatological evidence[1][6].

Traders should monitor no immediate weather catalysts, as June in São Paulo is climatologically stable with low variability and no scheduled atmospheric anomalies. There are no political debates, campaign-finance disclosures, or conventions that influence local weather patterns, confirming the market leans entirely on historical climate data rather than event-driven volatility[1]. The most relevant news source for context is the long-term weather average from Weather2Travel, which confirms that 25°C is the typical upper limit for daytime temperatures in June, with only 5–6 hours of sunshine daily and 9–10 rainy days expected[1]. With settlement occurring before midday, the chance of an extreme heat spike is negligible, reinforcing the 0% probability as factually grounded rather than speculative[1][8].

Sources: 1 · 2 · 3 · 4 · 5

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 Sao Paulo on June 30? 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.

What resolution source is used for elections?

Polymarket defines the source per contract — usually Associated Press (AP Race Call), Reuters or the official electoral commission. The source is stated in contract details before the market opens.

Which platform has the deepest political liquidity?

Polymarket — by far. US 2024 presidential volume was ~$3.5B vs Kalshi (~$200M) and Betfair (~$120M). Where Polymarket is geo-blocked, brokers like Election Predictions UK route into the same order book at 0% fees.

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.