Highest temperature in Tokyo on July 4?

Platform comparison

Market context

On 4 July 2026, the Tokyo Haneda Airport Station will record its peak daily temperature in degrees Celsius, a single data point that determines the outcome of a niche weather prediction market. While one platform currently shows a 0% implied probability for the highest temperature exceeding 26°C, Polymarket assigns a 57% chance to 27°C and a 26% chance to 26°C, highlighting a stark divergence in market sentiment between exchanges. This discrepancy stems from differing pricing models: Polymarket displays decimal odds and implied probabilities directly, whereas Kalshi and Betfair often emphasise fractional odds or require traders to calculate implied probabilities, alongside variations in fee structures and KYC requirements that affect liquidity depth on such specific events.

Historical July weather in Tokyo consistently supports higher temperatures, with mid-to-late July routinely hitting 36°C to 40°C and humidity exceeding 95%, effectively turning the city into a concrete jungle where heat lingers until evening [2]. Recent records reinforce this trend, as Japan set its highest-ever temperature of 41.2°C in Tamba City on 30 July 2025, with Tokyo’s Ome City reaching 40.4°C on the same day [7][8]. The current 0% probability on one exchange appears inconsistent with these climatic baselines, suggesting traders should scrutinise whether the market is mispricing the likelihood of a standard hot summer day or reacting to an unannounced local anomaly.

Traders must monitor the daily forecast for Tokyo Haneda International Airport, which projects July 2026 highs between 76°F and 91°F (approximately 24°C to 33°C), a range that comfortably exceeds the 26°C threshold [4]. Key dependencies include real-time updates from the Japan Meteorological Agency and Wunderground, the official resolution source, as any sudden shift in cloud cover or wind patterns could alter the peak temperature [1]. With the settlement window closing at 12:00 UTC on 4 July 2026, the market remains highly sensitive to the final hours of the afternoon, when peak temperatures typically occur between 11 AM and 6 PM [2].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Highest temperature in Tokyo on July 4? 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

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.

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 has a different geo footprint and routes to Polymarket's order book at 0% fees.