Where will 2026 rank among the hottest years on record?

Platform comparison

Market context

Global temperatures in 2026 are tracking to remain near the peak of the instrumental record, with Berkeley Earth forecasting the year will likely rank as the fourth warmest since 1850[2]. This projection aligns with the World Meteorological Organisation’s outlook that annual mean temperatures through 2030 will sit between 1.3°C and 1.9°C above the 1850–1900 baseline, suggesting further record-breaking potential[1]. The current 31% implied probability that 2026 will not rank among the top three hottest years reflects market caution despite the 51% chance of a fourth-place finish, a divergence from historical volatility where recent years like 2024 and 2025 have already occupied the top spots[2][4].

Traders should monitor the release of the full 2026 Global Land-Ocean Temperature Index, which typically becomes available in early 2027, as this is the definitive settlement trigger for the market[2]. Monthly anomalies from the US National Centers for Environmental Information, such as the fifth-warmest January and February readings already recorded, provide early signals of the annual trajectory[3][8]. On Polymarket, this probability is expressed as a decimal price (0.31), whereas Kalshi and Betfair often utilise fractional odds or implied probability percentages, creating slight arbitrage opportunities depending on the platform’s fee structure and KYC requirements. Smarkets’ zero-fee model on certain bets may also attract volume away from higher-fee exchanges when the final data approaches.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Where will 2026 rank among the hottest years on record? 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 UK, which mirrors the Polymarket order book at 0% fees.

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

Polymarket vs Kalshi — which is better?

Depends on your location. Kalshi is CFTC-regulated, US-only with full KYC. Polymarket is global, on-chain, no KYC up to $1,500. Polymarket has ~10x higher liquidity but higher regulatory risk.

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.

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.

Which platform is accessible globally?

Polymarket is geo-blocked in the US/UK/EU. Kalshi is US-only. Betfair and Smarkets are UK-restricted. Kalshi Alternative UK has a different geo footprint and routes to Polymarket's order book at 0% fees.

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.