Resolution criteria on PolyGram: This market will resolve to the temperature range that contains the lowest temperature recorded at the London City Airport Station in degrees Celsius on 30 May '26. The resolution source for this market will be information from Wunderground, specifically the lowest temperature recorded for all times on this day for the London City Airport Station, available here: https://www.wunderground.com/history/daily/gb/london/EGLC. To toggle between Fahrenheit and Celsius, click the gear icon next to the search bar and switch the Temperature setting between °F and °C. This market can not resolve until the first data point for the following date has been published on the resolution source.
Real-money prediction markets aggregate live odds from thousands of traders, surfacing a sharper probability than any single forecast. Current odds favour the NO side at 1%, making this a high-confidence market with 2 days to resolution — final-48h markets historically see the largest volume spikes, backed by $11K of resting liquidity.
PolyGram is an on-chain prediction market where you trade YES or NO outcome shares with real USDC on Polygon. For this market, buy YES if you believe the event will happen, or NO if you think it won't. Your maximum loss is your stake — winning shares pay $1.00 each at resolution. Unlike sportsbooks, there is no house edge: prices are set by supply and demand from other traders and reflect the crowd's real-time probability.
Market outcomes
| 9°C or below | 1% YES | 99% NO |
| 10°C | 2% YES | 98% NO |
| 11°C | 1% YES | 99% NO |
| 12°C | 5% YES | 96% NO |
| 13°C | 18% YES | 83% NO |
| 14°C | 20% YES | 81% NO |
| 15°C | 20% YES | 80% NO |
| 16°C | 20% YES | 80% NO |
On 30 May 2026, the lowest temperature recorded at London City Airport will determine which range this market settles into. The current order book on Polymarket implies just a 1% probability that the lowest temperature falls into the YES range, suggesting traders expect temperatures to remain above whatever threshold defines that bracket.
London's May temperatures typically range between 8–16°C for daily lows, with frost or near-freezing conditions becoming increasingly rare as spring progresses. Historical data from the Met Office shows that temperatures below 5°C in late May occur in roughly 5–10% of years, whilst sub-zero readings are exceptionally uncommon at this time of year. The 1% implied probability reflects the statistical rarity of unusually cold conditions persisting into late spring, though late May cold snaps have occurred—notably in 2020 when temperatures dipped to 2°C in parts of southern England.
The primary catalyst affecting this market will be seasonal weather patterns emerging in April and May 2026. Long-range forecasts from the UK Met Office, typically issued 10–14 days ahead, will provide increasing clarity as the settlement date approaches. Any significant Arctic or polar air incursions into northern Europe during late May would shift probabilities materially, though such events remain statistically improbable. Traders should monitor European weather models and any official Met Office warnings for unseasonable cold during the final weeks before settlement.
This market settles from the official outcome published at https://www.wunderground.com/history/daily/gb/london/EGLC. A proposer submits the final result to the UMA optimistic oracle on Polygon; the two-hour dispute window closes and payouts clear in USDC.
For this market, the resolution date is 30 May 2026. A UMA proposer can submit the outcome from that moment; the two-hour dispute window closes at , and assuming no counter-claim is staked, winning USDC clears to trader balances by approximately .
If a dispute is filed inside the two-hour window, the outcome escalates to UMA token-holder voting, which extends settlement by roughly 48 hours. Because this market resolves from a publicly verifiable feed (https://www.wunderground.com/history/daily/gb/london/EGLC), the probability of dispute is materially lower than the overall 0.5% PolyGram baseline — most disputes occur on markets with ambiguous wording or non-public resolution sources.
Withdrawal pace from your PolyGram balance is non-custodial and immediate — once payout clears, funds are yours to send to any Polygon wallet you control. Funds clear directly to your in-app USDC balance on Polygon. Withdrawals are non-custodial: send to any address you control, typical confirmation under 30 seconds, gas paid in USDC if you'd rather not hold MATIC.
Minimum order size on PolyGram is $1.00, with no maximum cap aside from available book depth. Orders route into Polymarket's on-chain CLOB on Polygon; the matching engine pairs YES buyers with NO buyers atomically — every executed trade is settled on-chain with no counterparty risk. For "Lowest temperature in London on May 30?", order-book behaviour for this market reflects the underlying volatility of the outcome — patient limit orders typically fill closer to mid than market orders.
The trade ticket includes a slippage box (default 2%, configurable 0.1%-10%) that caps the worst-case entry price. Your maximum loss is your stake — winning YES (or NO) shares pay $1.00 each at resolution. With this market's current book depth ($11K of resting liquidity), a $100 order should fill with single-cent slippage at the displayed mid-price.
PolyGram charges 0% house edge — no spread mark-up, no rake on winnings, no withdrawal fees beyond network gas. The platform earns exclusively from optional features (copy-trade boosts, advanced order types, the yield vault on idle USDC); the trading surface itself is at-cost.
The mechanics for trading "Lowest temperature in London on May 30?" are the same as any other PolyGram event contract. Each YES share resolves to $1 if the event happens, or $0 if it doesn't. The current price between 0¢ and 100¢ is the market's probability estimate, set live by the order book.
$222 in lifetime turnover and $11K of resting liquidity puts this market in the below the median by volume for weather contracts on PolyGram. Order-book depth is modest — expect a couple of cents of slippage on $1k+ trades.
Last 24 hours alone saw $222 in turnover, well above the lifetime daily-average for this market — a clear sign of news catalysing trader activity right now.
The market has been open for under a month — fresh enough that information asymmetry remains a real factor.
Higher-volume markets tend to have tighter spreads and faster price discovery — meaning the displayed YES/NO percentages are more likely to reflect the true crowd-implied probability rather than a single trader's directional view.
Resolution is sourced from https://www.wunderground.com/history/daily/gb/london/EGLC. Settlement is executed by the UMA optimistic oracle on Polygon, with a 2-hour dispute window before payouts clear.
This prediction market is scheduled to close on 30 May 2026. After the resolving event occurs, settlement typically clears within 24 hours once the UMA optimistic oracle confirms the outcome. All payouts are in USDC on the Polygon network.
To trade on this prediction market, create a free PolyGram account at polygram.ink, deposit USDC via Polygon, and place a YES or NO order on the outcome you believe in. You can learn more on our how-it-works page. Your maximum loss is limited to your stake — there is no leverage or margin.
When the outcome is determined, winning YES shares pay out $1.00 each in USDC, while losing shares pay $0. Settlement is handled by the UMA optimistic oracle on Polygon — a proposer submits the result, a two-hour dispute window opens, and if uncontested, payouts are distributed automatically. You can withdraw your winnings to any Polygon wallet.
Prediction-market positions can lose 100% of staked capital. Outcomes are uncertain by definition — historical accuracy of crowd-implied probabilities is high in aggregate but not for any single market. PolyGram does not provide investment advice. Trade only with capital you can afford to lose. For "Lowest temperature in London on May 30?", the considerations above apply directly — Trade size should reflect the binary nature of the payoff: even a 70% probability event resolves NO 30% of the time, so any single position can lose 100% of staked capital.
Regulatory status varies by jurisdiction. Germany, the United States, and most EU countries treat Polymarket-style event contracts under one of three frameworks: financial derivative, gambling product, or unregulated novel asset. Consult local counsel before trading.
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