Pronóstico: Highest temperature in San Francisco on June 30?

Platform comparison

Market context

The underlying real-world event is the highest temperature recorded at San Francisco International Airport on 30 June 2026, measured in degrees Fahrenheit. Today, Polymarket prices the YES contract for this temperature range at 0%, implying the crowd believes the event will not occur within the specified bracket. This conditional token sits on the Polygon blockchain, settled in USDC, where traders can buy or sell exposure to the outcome based on on-chain mechanics.

Historical data frames this probability sharply: daily highs in June at KSFO typically climb from 68°F to 71°F, rarely exceeding 80°F or falling below 61°F[2]. The first half of summer 2026 has already been the coldest since 1965, with an average maximum of just 67.6°F through mid-July[6]. Such a persistent cool pattern suggests the market’s 0% pricing may reflect a genuine deviation from normal summer heat, not an arbitrary dismissal.

Traders should monitor the National Weather Service’s daily climatological reports for KSFO, which list the 73°F normal maximum and 92°F record high[9]. Any sudden shift in wind patterns from the west, currently at 18 mph with rising pressure, could alter the thermal profile[1]. While no immediate heatwave announcements exist, the dependency on marine layer persistence remains critical; a breakdown could trigger rapid warming, though current forecasts still cap highs at 70°F[5].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Pronóstico: Highest temperature in San Francisco on June 30? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Polymarket Argentina, which mirrors the Polymarket order book at 0% fees.

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 Polymarket Argentina. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

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.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

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.