Miami Lowest Temp May 27: Can 80-81°F Hold?

Late May in Miami runs warm. The Atlantic is heating up, sea surface temperatures are elevated, and overnight lows rarely break from the low-to-mid eighties once humid season locks in. The market has priced the 80-81°F band as the most likely overnight low for May 27, but at 26.5% implied probability, that is far from a consensus call. The data is telling us something specific: Miami’s overnight low distribution in late May is wide enough that no single bin captures the majority.

The market question asks for the lowest temperature recorded in Miami on May 27, 2026, resolving at noon on that date. The 80-81°F band prices at $0.27 YES and $0.74 NO, with $1,041 in total volume and $314 traded in the last 24 hours. Liquidity sits at $26,147, which is deep relative to volume. The end date is May 27, 2026.

How the 80-81°F Miami Temperature Contract Works

YES pays out if the verified lowest temperature in Miami on May 27 falls between 80°F and 81°F inclusive. NO covers every other outcome, from the cooler bins at 73°F or below all the way up to 92°F or higher. The resolution source is Polymarket’s market resolution process, which draws on official temperature observation data for Miami.

• YES ($0.27): Overnight low lands exactly in the 80-81°F range on May 27.
• NO ($0.74): Overnight low falls in any other band, including 78-79°F, 82-83°F, or beyond.

The NO outcome is not a single rival scenario. It is the combined weight of ten other temperature bands. Miami’s late-May overnight lows historically cluster between 76°F and 84°F, so the genuine competition for probability sits in the 78-79°F, 82-83°F, and 76-77°F bins. A frontal passage, a rain event, or a period of high cloud cover on the night of May 26 into May 27 could push the low below 80°F. A stalled high-pressure system with clear skies and onshore flow could push it above 81°F. Either shift lands the contract in NO territory.

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Momentum and Market Signals

The trend score sits at 43.65, pointing toward mild bearish pressure on the YES side. No hourly or 24-hour price change data is available, so the directional signal is soft. The most likely driver is short-range forecast updates from the National Weather Service Miami forecast office, which posts updated model guidance twice daily. Any model run showing the May 27 low straying outside 80-81°F will put additional downward pressure on YES.

Total volume is $1,041 with $314 in the last 24 hours. Liquidity is $26,147, which is deep for this market size. That depth means the current price of $0.27 is unlikely to swing wildly on a single trade, but thin overall volume means a large bet could still move the contract meaningfully. The market data does not reflect strong conviction from either side yet.

• The 80-81°F bin holds the top implied probability at 26.5%, but that still leaves nearly three-quarters of probability distributed across rival outcomes.
• The 78-79°F and 82-83°F bands are the most likely competitors, based on Miami’s late-May climatology.
• The trend score of 43.65 reflects mild bearish lean on YES, consistent with forecast uncertainty this far from resolution.
• No large trades have been recorded, so there is no institutional signal to read into the current price.
• Liquidity at $26,147 is unusually high relative to volume, suggesting market makers are holding positions wide ahead of the resolution date.

Lines Analysis: Miami’s Late May Overnight Low

Miami’s climatological overnight low in late May averages in the low-to-mid seventies on the Fahrenheit scale at Miami International Airport, the standard observation point. However, urban heat island effects, sea surface temperature anomalies in the Florida Straits, and the transition into early wet season can push overnight minimums several degrees above that average. An 80-81°F overnight low is on the warm side of the historical distribution but not outside it, especially during years with elevated Atlantic basin temperatures. The National Weather Service Miami office forecast for May 27 will be the single most important data point for this contract.

What makes the NO side real is the breadth of competing outcomes. The 78-79°F band represents a modest cooling scenario that a brief wind shift or afternoon thunderstorm could produce. The 82-83°F band represents continued heat retention under a high-pressure ridge. Miami’s overnight lows are sensitive to wind direction: southwest flow from the warm Gulf Stream keeps temperatures elevated, while a brief northeast wind intrusion can drop the low by two to four degrees. Any forecast indicating a wind shift toward the northeast on the night of May 26 would move probability sharply toward the cooler bins.

• National Weather Service Miami: each model run update shifts the probability distribution across all temperature bins.
• GFS and Euro model agreement: if both models converge on a specific overnight low range, the market will follow.
• Sea surface temperatures in the Florida Straits: elevated SSTs support warmer overnight lows and favor the upper bins.
• Thunderstorm activity on May 26: an afternoon convective event can evaporatively cool the overnight low by two to three degrees, pushing toward the 78-79°F range.
• Any frontal boundary in the Southeast: even a weak front dropping into South Florida would reprice the cooler bins dramatically.

Total volume of $1,041 is thin. The data currently favors the 80-81°F bin as the single most likely outcome, but the probability spread across ten alternative bins means NO holds structural advantage. The next 48 hours of NWS forecast updates are the decisive signal.

LINES VERDICT

Narrow Leader, Wide Field

The 80-81°F bin leads the field by probability, but Miami’s overnight low distribution in late May is diffuse enough that the plurality winner still loses nearly three-quarters of the time. The market is pricing uncertainty, not science, and the science here is genuinely uncertain across a wide range of outcomes.

What the market says: At 26.5% implied probability with resolution on May 27, this contract has roughly two days left to settle. Volatility will compress sharply as the NWS 24-hour forecast for Miami locks in.

Key unknown: The National Weather Service Miami office’s next two forecast cycles are the decisive input. Any shift in the modeled overnight low outside the 80-81°F window will reprice this contract immediately.