Highest temperature in Warsaw on July 27?

Platform comparison

Market context

On 27 July 2026, the highest temperature recorded at Warsaw Chopin Airport will fall into one of several defined ranges. This market settles against historical weather data from Wunderground, the standard source for aviation meteorology across Central Europe. Warsaw's summer temperatures typically peak in the 24–28°C range during late July, though heat waves can push readings into the low 30s. The settlement window closes at midday UTC, meaning only temperatures recorded up to that point count toward resolution.

Historical July data from Warsaw shows considerable year-to-year variance. The city recorded 30.5°C on 27 July 2012 and 27.1°C on the same date in 2019, illustrating the 3–4°C spread common in late-summer conditions. The 0% implied probability visible on Polymarket suggests either no active traders or a technical issue with market initialisation, a pattern sometimes seen on weather markets with narrow settlement windows. Kalshi and Betfair typically show more liquidity on European weather contracts, though their decimal-odds displays and fee structures (Kalshi's 2% settlement fee versus Polymarket's variable maker-taker model) create different effective margins for traders comparing across platforms.

Traders should monitor European weather forecasts from mid-July onward, particularly jet-stream positioning and any Atlantic high-pressure systems that might drive continental warming. The Polish Meteorological Institute publishes extended outlooks roughly two weeks ahead. Because this market settles on a specific date with no adjustment window, forecast uncertainty tightens sharply in the final 48 hours—the period when most price discovery typically occurs on weather contracts across all major platforms.

Methodology

We read Highest temperature in Warsaw on July 27? from four platform perspectives: Polymarket (on-chain CLOB), Kalshi (CFTC-regulated exchange), Betfair Exchange (sports book exchange), Smarkets (peer-to-peer betting exchange). Polymarket's live mid is the canonical probability; the side-by-side columns benchmark fees, KYC, settlement currency and deposit rails so you can choose the venue that fits your jurisdiction and trade size.

Resolution & payout

Polymarket settles via UMA Optimistic Oracle on Polygon. A proposer posts the outcome with a bond, the two-hour window runs, then the smart contract pays USDC.

Kalshi settles USD through the CFTC-regulated clearinghouse — the cleanest variant, with heavier KYC. Betfair Exchange settles in account currency (GBP/EUR), net of 2-5% commission. Smarkets follows the same model as Betfair with a lower default 2% commission.

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.

What about Smarkets as an alternative?

Smarkets is a UK betting exchange with a lower default commission (2%) than Betfair. Liquidity on political markets is below Polymarket, comparable to Kalshi. Geo-blocked in many jurisdictions.

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.