Trade: Highest temperature in Miami on May 15?

Market context

On 15 May 2026, Miami International Airport will record a daily high temperature, which will fall within one of several defined ranges. The market settles based on historical data from Wunderground, using the airport station as the official measurement point. Current order book activity on Polymarket shows 0% implied probability, indicating either minimal trading volume or extreme confidence in specific temperature ranges dominating the available liquidity.

Miami's May climate is characterised by consistent warmth and increasing humidity as the region transitions toward summer. Historical May highs at Miami International Airport typically range between 86°F and 92°F, with the median around 89°F. The 0% probability reading suggests traders have concentrated positions in the most likely ranges, leaving peripheral outcomes unpriced or illiquid. This pattern is common in weather markets where seasonal norms create strong consensus around central estimates.

The primary variable affecting May 15 temperatures will be Atlantic weather patterns in the preceding weeks. Tropical systems occasionally influence South Florida's weather in mid-May, though major hurricanes remain statistically unlikely at this time of year. Sea surface temperatures, upper-level wind patterns, and any developing low-pressure systems warrant monitoring through standard meteorological forecasts as the settlement date approaches. The National Weather Service's extended outlooks, typically issued 8–14 days before the event, will provide the most actionable information for traders reassessing positions closer to the resolution window.

Resolution source

This market settles from the official outcome published at https://www.wunderground.com/history/daily/us/fl/miami/KMIA. A proposer submits the final result to the UMA optimistic oracle on Polygon; the two-hour dispute window closes and payouts clear in USDC.

How to trade this market step by step

The mechanics for trading "Highest temperature in Miami on May 15?" 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.

1. Sign in on polygram.ink with your email — no full KYC under $1,500 lifetime trading volume.
2. Deposit USDC on Polygon (lowest fees, ~$0.01 per transaction) or Ethereum. Funds credit after 12 confirmations.
3. Pick a side. Buy YES if you believe the event will happen; buy NO if you think it won't. The current YES price reflects the market's collective probability.
4. Size your position. If you stake 100 USDC at 50% YES, you'll receive shares that pay $200 if YES resolves true — a 100% gross return. If NO resolves, your shares are worth $0.
5. Set risk controls (optional). Stop-loss, take-profit, and limit-order types all supported. Use the trade ticket's slippage box to cap your maximum entry price.
6. Wait for resolution. When the event resolves on-chain via the UMA optimistic oracle, the winning side settles to 100¢ automatically and USDC hits your balance within seconds. Withdrawable to any wallet you control.

How active is this market?

$14K in lifetime turnover and $47K of resting liquidity puts this market in the below the median by volume for weather contracts on PolyGram. Order-book depth is strong — order books support five-figure trades with single-cent slippage.

Last 24 hours alone saw $14K 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.

Key terms

YES / NO share

A binary outcome token that pays $1.00 if the underlying claim resolves true (YES) or false (NO), and $0 otherwise. The market price between 0¢ and 100¢ is the implied probability.

CLOB

Central limit order book. The matching engine that pairs YES buyers with NO buyers (effectively the same trade). Polymarket's CLOB on Polygon executes trades on-chain via the conditional-tokens framework.

Liquidity

USDC capital sitting in resting limit orders inside the order book. Deeper liquidity means smaller slippage on large trades and a tighter bid-ask spread.

UMA optimistic oracle

The on-chain dispute system that settles each Polymarket market. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution.

Slippage

The difference between the displayed mid-price and your fill price. Affects market orders most; limit orders avoid slippage but may take time to fill.

Conditional token

ERC-1155 outcome share issued by Gnosis Conditional Tokens on Polygon. The token type that resolves to $1.00 or $0.00 at settlement.

See the full prediction-market glossary →

Frequently asked questions

Risk and regulatory note

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.

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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