Highest temperature in Shanghai on July 21?

Platform comparison

Market context

Shanghai's summer heat peaks in late July, with daily highs typically ranging from 32–35°C during the monsoon season. The settlement hinges on the maximum temperature recorded at Pudong International Airport on 21 July 2026, resolved via Wunderground's historical weather database. The 0% crowd probability suggests traders are either absent from this market or pricing in an exceptionally narrow temperature band as the "correct" outcome—a common pattern in niche weather markets where liquidity clusters around round-number thresholds rather than distributing across the full range.

Historical Shanghai July data shows high variability. The city has recorded extremes from 28°C on cool, rainy days to 37°C during heat waves, with 2013 and 2017 seeing peaks above 36°C. Comparable airport-based weather markets on Kalshi and Polymarket typically see tighter spreads than traditional sportsbooks because settlement is objective and verifiable; however, Betfair's decimal-odds interface and Smarkets' fractional pricing can obscure the true probability distribution when ranges are granular. The current 0% reading suggests either the market has not yet attracted sufficient volume to establish a baseline, or the implied range is so specific that no traders have positioned accordingly.

Traders monitoring this market should track China Meteorological Administration seasonal forecasts and any El Niño or monsoon pattern shifts announced before July 2026. Pudong's urban heat-island effect and airport infrastructure also influence readings relative to broader Shanghai measurements, making historical airport-specific data more relevant than city-wide averages. KYC requirements vary across platforms—Kalshi operates under US regulation, whilst Polymarket and Smarkets serve international users with different verification thresholds—which may explain the sparse liquidity in this particular contract.

Methodology

This page compares Highest temperature in Shanghai on July 21? specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. The live probability is the Polymarket mid; the comparison columns summarise each venue's fee structure, KYC, settlement currency and payment rails. Every CTA routes to Kalshi Alternative, which mirrors the Polymarket order book at 0% fees.

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. Kalshi Alternative 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.