Tokyo June 10 High Temp: Will 22°C Hold?

A single weather market just moved more than a quarter of its value in 24 hours. The 22°C outcome for Tokyo’s highest temperature on June 10 now sits at 86.5% implied probability, driven by a sharp momentum surge that began June 8 and accelerated through June 9. The data doesn’t care about the politics, and right now the data is pointing squarely at a mild, early-June day in Tokyo.

The market asks: what will Tokyo’s highest temperature be on June 10? The 22°C outcome is priced at 0.87 YES and 0.14 NO. The market closes June 10 at 12:00 UTC. Total volume stands at $84,849, with $66,288 traded in the last 24 hours alone.

How the Tokyo Temperature Contract Works

This contract resolves to YES if Tokyo’s official highest temperature on June 10 is recorded at exactly 22°C. Resolution follows the official measurement source designated at market creation. All other temperature outcomes, from 17°C or below up through 27°C or higher, trade as separate contracts on the same board.

• YES (22°C exactly): priced at 0.87, implying an 86.5% probability.
• NO (any other temperature): priced at 0.14, implying a 13.5% probability.

The NO outcome pays out if Tokyo’s measured daily high lands on any temperature other than 22°C. Early June in Tokyo sits in a transitional window between spring and the early rainy season. A stronger trough, an earlier onset of the baiu (plum rain) front, or an unseasonably warm southerly flow could push the reading to 23°C or above. A cool marine air intrusion could drag it to 21°C or below. Either scenario collapses the YES price overnight.

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Momentum and Market Signals

The momentum composite, combining a flat 1-hour change, a 26% 24-hour surge, and a trend score of 59.30, points to a single driver: rapidly converging forecast models. Price moved up 7.5% on June 8, another 8% on June 9, and then accelerated 13.5% later that same day. That kind of staircase pattern reflects forecast models progressively locking onto a narrow temperature band as the event date approaches.

Total volume of $84,849 with $66,288 arriving in 24 hours is notable for a one-day weather market. Liquidity sits at $118,910, which actually exceeds total volume. That combination means the order book is deep enough to absorb a shift, but if a late forecast update breaks from the 22°C consensus, the price can still move sharply before close. This is not a deep liquid market by broader standards. New data moves it.

Competing Temperature Outcomes (Polymarket, as of 2026-06-09)

• 23°C outcome: the most likely alternative, tracking closely behind the 22°C lead.
• 21°C outcome: the primary downside alternative, reflecting cool marine air scenarios.
• 24°C and above: lower-probability outcomes that gain traction only if warm southerly flow accelerates ahead of schedule.
• 17°C or below through 20°C: deep tail outcomes with minimal market activity.

Key Factors

• The 24-hour price change of +26% reflects multiple forecast model runs converging on a 22°C reading for June 10 Tokyo.
• The 1-hour change of 0.0% suggests the immediate pre-close window has stabilized. No new forecast surprise has landed in the last hour.
• Liquidity of $118,910 exceeds traded volume, indicating patient capital on both sides of the book.
• Early June Tokyo climatology supports mild highs in the low-to-mid 20s. The 22°C reading sits within normal range for this date.
• The trend score of 59.30 confirms sustained directional conviction without entering the extreme overbought territory that precedes sharp reversals.

Lines Analysis: What the Temperature Data Supports

Here’s what the measurements are telling us. Numerical weather prediction models running 24 to 48 hours out in Japan typically achieve their highest skill scores precisely in this forecast window. When multiple independent models, the Japan Meteorological Agency’s mesoscale model, and global ensemble systems align on a specific reading, the market tends to follow. The price action since June 8 is consistent with exactly that kind of progressive model convergence. The 22°C outcome did not open as the leader. It climbed there as forecast uncertainty collapsed.

What makes the NO side real is geography and timing. Tokyo in early June sits under the influence of the baiu front, a quasi-stationary boundary that can shift daily high temperatures by three to four degrees depending on whether marine air or continental warmth dominates. A front positioned slightly farther south than current forecasts suggest would hold the high at 21°C. A slight northward shift in the Pacific high could push readings to 23°C or 24°C. The window closes at 12:00 UTC on June 10, which is early afternoon Japan Standard Time. Morning temperature trajectory will be visible before resolution, giving late traders a narrow informational edge.

Signals to Monitor

• Japan Meteorological Agency’s 6-hour forecast update for Tokyo June 10 is the single most important signal. Any revision away from 22°C reprices this contract immediately.
• Global ensemble model agreement, specifically the European Centre for Medium-Range Weather Forecasts ensemble mean, confirms or challenges the JMA local forecast.
• Observed morning temperature in Tokyo on June 10 sets the trajectory. A reading above 20°C by 09:00 JST supports the 22°C or higher range.
• Baiu front positioning, tracked via JMA surface analysis charts, determines whether cool marine air undercuts the forecast high.
• Any surprise shift in Pacific high pressure strength could accelerate warming and shift probability mass toward 23°C or 24°C outcomes.

The market is pricing uncertainty, not science. Total volume of $84,849 reflects real trader conviction in a short-duration contract. The data trajectory favors the 22°C outcome. The forecast window is narrow and the models are aligned. But this contract resolves on a single measurement, taken on a single day, in a city where the baiu season introduces meaningful day-to-day variance. One late forecast update is all it takes.

Forecast Convergence Confirmed

Multiple model runs aligning progressively over 48 hours drove this contract to 86.5%, and the stabilizing 1-hour price action suggests the market has absorbed available forecast information. The data supports the 22°C outcome as the clear probability leader heading into resolution.

What the market says: At 86.5%, the market treats a 22°C Tokyo high on June 10 as the strong base case. Volatility remains real. This contract closes at 12:00 UTC on June 10, and any final forecast revision before that window will reprice it fast.

Key unknown: The Japan Meteorological Agency’s next forecast update is the contract-moving event. A shift of even one degree in the official high temperature guidance would collapse the 22°C probability and redistribute value across adjacent outcomes.