Where will 2026 rank among the hottest years on record?

Platform comparison

Market context

Global temperatures in 2026 are tracking as a top-tier contender for the hottest year on record, with early data suggesting it will likely rank between first and fourth historically. Berkeley Earth calculates a 16% chance 2026 becomes the warmest year, rising from 10% at the start of the year, while a 36% probability places it second hottest [2]. The final ranking hinges heavily on El Niño timing and strength, with a 30% likelihood that 2026 anomalies exceed the 1.5°C benchmark above pre-industrial averages [2].

Traders should monitor monthly NOAA and EU Climate Service releases, particularly June and July updates, as May 2026 already ranked as the second-warmest May globally since 1850 [9]. The World Meteorological Organisation forecasts annual mean temperatures for 2026–2030 between 1.3°C and 1.9°C above the 1850–1900 average, reinforcing the likelihood of another record-breaking year [1]. Any sudden shift in El Niño declarations or Pacific Ocean heat content will act as the primary catalyst for probability swings.

On Polymarket, the 34% YES implied probability translates to decimal odds of approximately 2.94, whereas Kalshi lists this as a binary contract priced at 34 cents with no fee on wins, contrasting with Betfair’s commission-based model and Smarkets’ lower fee tier. Polymarket requires no KYC for most users, while Kalshi mandates full identity verification and US residency, creating divergent liquidity pools despite identical underlying resolution logic based on the Global Land-Ocean Temperature Index.

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, 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.

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.

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.