London June 13 Low Temp: Will 13°C Hold?

A single weather measurement is driving one of the sharpest 24-hour price moves on Polymarket right now. The contract asking for London’s lowest temperature on June 13 has seen its leading outcome, 13°C, surge from a coin-flip to a near-certainty overnight. The market is pricing 13°C at 77.5% implied probability. That kind of move in less than a day means traders found something the earlier pricing was missing.

The market question asks: what will London’s lowest temperature be on June 13? The 13°C outcome sits at $0.78 YES and $0.23 NO. Resolution closes at noon UTC on June 13, 2026. Total volume stands at $3,982, with $2,903 of that trading in the last 24 hours.

How the Contract Resolves: 13°C vs. the Field

This contract resolves to YES if London records a minimum temperature of exactly 13°C on June 13, measured against the official resolution source. The competing outcomes span a wide range: 9°C or below up through 19°C or higher. Only one outcome pays. The YES side wins if the overnight or early-morning low lands precisely at 13°C. The NO side covers everything else, including 12°C, 14°C, and all other buckets.

• 13°C YES: $0.78 per share, 77.5% implied probability
• All other outcomes (12°C, 14°C, 11°C, 10°C, 15°C, and beyond): collectively priced at 22.5%

The NO case is real but narrow. London’s June overnight lows cluster tightly around 12°C to 14°C historically. For this contract to miss, the temperature would need to dip to 12°C or rise to 14°C at the measured low. A cloudier, wetter night pushes temperatures toward 14°C. A clearer night with low humidity pulls the low toward 12°C. The spread between those outcomes is the entire NO trade.

Momentum and Market Signals

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The momentum composite here is one-directional and sharp. The 24-hour price change of plus 18.0% with a trend score of 56.08 and flat 1-hour movement tells a specific story: a large information event hit this market during the trading day on June 12, and the price repriced fast. The most likely driver is updated short-range forecast model runs, specifically the European Centre for Medium-Range Weather Forecasts or UK Met Office guidance for June 13, which typically lock in overnight low predictions within 24 to 36 hours of the event.

Total volume of $3,982 and 24-hour volume of $2,903 flag this as a thin market. Liquidity of $18,595 is healthy relative to volume, but any single trade above a few hundred dollars can move the price meaningfully. The 77.5% implied probability reflects the current best guess, not a deep consensus. One sharp trader with fresh forecast data moved this contract. The whale trades section is empty, which means the repricing came from multiple smaller positions rather than one large bet.

• The 24-hour momentum of plus 18.0% aligns with updated June 13 forecast model output, likely released June 12 afternoon UTC.
• The 1-hour change of 0.0% suggests the new information is fully priced for now. The market is waiting for the next forecast update.
• Thin volume below $5,000 total means a single new forecast run or a large trade could shift the price by 5 to 10 percentage points.
• Liquidity of $18,595 is the buffer. The order book can absorb moderate trades without gap-filling.
• Trend score of 56.08 is moderate, not extreme. The market is confident but not locked in.

Lines Analysis: What the Forecast Data Is Saying

London’s June climate baseline supports the 13°C read. The city’s average June minimum temperature sits in the 12°C to 14°C range, with 13°C the statistical mode for mid-June overnight lows. Short-range deterministic forecast models running within 24 to 48 hours of an event carry skill scores above 90% for surface temperature predictions in the UK. When those models agree on 13°C, the market is essentially tracking model consensus, not speculation. The data doesn’t care about the politics, and in this case, the data is pointing at one number.

What makes the NO case worth watching is the forecast spread. Ensemble model runs for overnight lows carry uncertainty of plus or minus 1°C even at 24-hour lead times. A cloud cover change, a frontal passage timing shift, or urban heat island variation between weather stations can land the official reading at 12°C or 14°C. The market is pricing the central forecast, but the tails are alive.

• UK Met Office short-range model output for June 13 is the single most important data source. Any update to that forecast before resolution reprices this contract.
• Ensemble spread narrowing toward 13°C would push the YES price toward 85% or higher.
• A forecast shift to 14°C as the central value would collapse the YES price quickly given thin volume.
• Actual overnight station readings from London weather stations, if available before noon resolution, will confirm or contradict the forecast.
• Cloud cover and wind speed forecasts for June 12 to 13 overnight are the physical drivers to watch.

Total volume of $3,982 is thin. The data favors the 13°C outcome based on the repricing pattern and UK climate baselines for mid-June. But this market resolves in less than 16 hours from the writing timestamp, and forecast uncertainty at this range is real.

Forecast-Aligned, Thin Market

The 18% surge in the last 24 hours reflects a sharp forecast convergence on 13°C. Here’s what the measurements are telling us: short-range model skill at this lead time is high, and London’s mid-June climatology supports this outcome as the modal value. The market is pricing uncertainty, not science, and right now the science is pointing one direction.

What the market says: 77.5% implied probability means traders are confident but not certain. With resolution in hours and thin volume below $5,000, a single updated forecast run or a larger trade could shift this price by several percentage points before noon UTC on June 13.

Key unknown: The next UK Met Office or ECMWF deterministic model run for June 13 overnight is the single data point that would reprice this contract. If that run shifts the central low forecast by even 1°C, the YES price moves sharply in a thin order book.