London May 26 Low Temp: 20°C at 30%

London’s overnight low temperature on May 26 is one of those markets where the meteorology is doing most of the work. The 20°C outcome sits at roughly 30% probability, making it the single most likely result in a fragmented field of eleven possible outcomes. No single temperature commands a majority here. That’s what makes this contract interesting: the market is pricing genuine meteorological uncertainty, not a binary call.

The market asks: what will the lowest temperature in London be on May 26? The 20°C outcome is priced at $0.30 YES and $0.70 NO, implying a 29.7% probability. The contract resolves May 26, 2026 at 12:00 UTC. Total volume stands at $9,377, with $7,548 traded in the last 24 hours.

How the London Temperature Contract Works

This contract resolves to a single temperature outcome based on the recorded lowest temperature in London on May 26. The resolution source is the market itself, using observed meteorological data. Eleven outcomes are available, spanning 13°C or below through 23°C or higher.

• YES at $0.30 pays out if London’s May 26 low registers exactly 20°C, implying a 29.7% chance.
• NO at $0.70 covers every other outcome, including 18°C, 19°C, 17°C, 21°C, 22°C, 16°C, 23°C or higher, 14°C, 15°C, and 13°C or below.

A 20°C low misses resolution when London’s overnight temperature settles above or below that single degree. Late May in London typically sees overnight lows in the 10°C to 14°C range, which means a 20°C overnight low would represent a notably warm night. The NO outcome captures all cooler readings, which historically dominate late May in central London.

Sponsored Partner

Momentum and Market Signals

The trend score sits at 54.07, a mildly neutral-to-bullish reading for the 20°C outcome. No 1-hour or 24-hour price change data is available to confirm directional momentum. The most logical driver for any recent price movement is updated numerical weather model output, specifically the ECMWF and UK Met Office short-range forecasts for May 26.

Total volume of $9,377 is thin. At under $10,000, this market can move sharply on a single updated forecast or a large individual trade. The $12,067 in liquidity actually exceeds traded volume, which is unusual and suggests the order book is relatively well-stocked compared to actual trader conviction. The $7,548 in 24-hour volume indicates most activity is very recent, likely tied to forecast model updates as the resolution date approaches.

• The 24-hour volume of $7,548 represents roughly 80% of total market volume, meaning interest spiked sharply as May 26 approached.
• Thin total volume below $10,000 means a single large bet could move the 20°C price several percentage points immediately.
• The trend score of 54.07 leans slightly toward the YES side without strong conviction in either direction.
• No momentum data for the 1-hour or 24-hour price change limits the ability to confirm a directional move.

Lines Analysis: What the Forecasts Are Telling Us

Here’s what the measurements are telling us. Late May overnight lows in London have historically averaged closer to 10°C to 13°C at Heathrow and central London stations. A 20°C overnight low would require an exceptionally warm and humid airmass, more typical of a heat event than standard late May conditions. For the 20°C outcome to resolve YES, the overnight minimum would need to stay elevated well above the seasonal average, likely driven by a persistent warm southerly flow or heat advection from continental Europe.

The NO outcome is real for straightforward reasons. Most of the probability mass sits in the cooler outcomes: 17°C, 18°C, and 19°C together likely account for a substantial share of the remaining 70% NO implied probability. A surface pressure pattern bringing Atlantic air or a clear-sky night with radiative cooling would drop the overnight low toward those cooler buckets. The data doesn’t care about the politics of which outcome traders prefer.

• UK Met Office short-range temperature forecast for May 26 is the single most important signal to monitor. Any update placing overnight lows near 20°C would push the YES price sharply higher.
• ECMWF ensemble model output for London overnight May 25 to 26 will price the probability of sustained warmth into the early morning hours.
• A synoptic shift to a westerly or northwesterly flow before May 26 would redistribute probability toward cooler buckets in the 13°C to 17°C range.
• Urban heat island effects in central London tend to keep overnight lows slightly elevated compared to surrounding areas, adding a small upward bias to any observed reading.

The market is pricing uncertainty, not science. At $9,377 in total volume, this is a thin contract with a fragmented outcome structure. The 20°C bucket holds the highest individual probability at 29.7%, but that still means roughly seven in ten outcomes land elsewhere. The data flow from weather models in the next 24 hours before resolution will determine whether that 30% holds or shifts.

LINES VERDICT

Fragmented Field, One Narrow Leader

The 20°C outcome leads a crowded eleven-way field, but a 30% probability in a fragmented market reflects meteorological uncertainty, not a directional call. Late May London climatology puts upward pressure on the NO side across cooler buckets.

What the market says: A 29.7% implied probability means the market sees 20°C as the single most likely outcome, but still expects a different temperature to resolve this contract roughly seven times out of ten. Thin volume below $10,000 means price can shift sharply before the May 26 resolution.

Key unknown: The UK Met Office and ECMWF short-range forecast updates for May 26 overnight temperatures are the single data point that will reprice this contract. Any model run placing the London overnight low firmly at 20°C or above would push YES significantly higher.

Scientific Context: London Late May Temperature Climatology

London’s late May overnight temperatures at Heathrow average roughly 10°C to 13°C based on long-term climatological records from the UK Met Office. Overnight lows reaching 20°C in late May are uncommon, typically associated with warm continental airmass intrusions or persistent southerly flow blocking cooler Atlantic influence. The urban heat island in central London adds approximately 1°C to 3°C to overnight readings compared to rural surrounding areas, which slightly elevates the probability of warmer outcomes at central London measurement stations. Any event that would push May 26 resolution toward 20°C sits well above the climatological norm for that date.

What would move price before May 26: A deterministic weather model consensus placing overnight lows in the 19°C to 21°C range would compress the probability spread and likely push the 20°C outcome above 40%. A shift toward a cooler synoptic pattern would redistribute probability toward the 14°C to 17°C buckets and deflate the 20°C price toward 15% or below.

How does the 29.7% probability translate to a bet?

A 29.7% probability means the market believes there is roughly a three-in-ten chance that London’s May 26 low lands exactly at 20°C. It is the leading single outcome in a fragmented eleven-way field.

What does the NO contract cover?

NO at $0.70 covers all ten other temperature outcomes, from 13°C or below through 23°C or higher. It pays out if London’s overnight low on May 26 is anything except exactly 20°C.

What data would move this contract’s price?

Updated UK Met Office and ECMWF weather model output for May 26 London overnight temperatures is the primary price driver. Any forecast shift toward sustained warmth or a cooler airmass would reprice the leading outcome significantly.

When does this contract resolve?

The contract resolves May 26, 2026 at 12:00 UTC, based on the observed lowest temperature in London on that date.

Is the volume and liquidity reliable here?

Total volume of $9,377 is thin. Liquidity of $12,067 exceeds total traded volume, which is unusual. Thin markets can move sharply on a single trade or a forecast update, so price stability is limited this close to resolution.