Miami Lowest Temp May 17: Can 78-79°F Hold?

Miami’s overnight low temperature on May 17 is sitting at the center of a tightly priced weather market. The 78-79°F outcome currently carries a 57% implied probability, with the contract resolving at noon on May 17, 2026. That slim majority reflects genuine meteorological uncertainty: late-spring overnight lows in Miami cluster in exactly this range, and small shifts in wind direction or cloud cover can push the reading a degree or two in either direction.

The momentum signal is unusually sharp for a micro-weather market. The 78-79°F contract posted a combined 24-hour and 1-hour price gain of roughly 24.5 percentage points, with a trend score of 85.12. That kind of movement in a single session on a low-volume contract almost always traces back to a specific forecast update, likely a National Weather Service model run tightening the overnight low projection toward the upper 70s for Miami-Dade. The data is driving this, not sentiment.

How the May 17 Miami Temperature Contract Works

This market asks one question: what will the lowest recorded temperature in Miami be on May 17, 2026, before the noon resolution cutoff? The contract resolves based on official meteorological measurements, most likely from NOAA’s Miami surface observation network or the National Weather Service Miami forecast office. The winning outcome is whichever temperature band contains the verified overnight low.

• 78-79°F (YES): Price 0.57, implied probability 57%. Pays out if the overnight low falls in this band.
• 76-77°F: Second most likely band, reflecting cooler-than-forecast scenarios.
• 80-81°F: Covers warmer overnight scenarios with less convective cooling.
• 74-75°F and below: Require a meaningful cold air intrusion, which is rare in mid-May Miami.
• 82°F and above: Requires persistent warm advection and suppressed radiative cooling overnight.

The market misses on 78-79°F when the overnight low either undershoots or overshoots the band. National Weather Service models for South Florida in mid-May typically show overnight lows ranging from 74°F to 82°F depending on onshore flow, cloud cover, and dewpoint. Any forecast revision that places the low firmly at 77°F or 80°F would pull liquidity toward those adjacent bands immediately.

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Momentum and Market Signals

The 24-hour price surge of 24.5% combined with a trend score above 85 is a single coordinated signal. In a micro-weather contract with a 24-hour resolution window, that kind of move almost always reflects a model consensus shift, likely the 12Z or 18Z National Weather Service GFS or NAM model run placing the Miami overnight low squarely in the 78-79°F range with reduced spread.

Total market volume sits at $10,299, with $3,076 traded in the last 24 hours. Liquidity is $43,243. Volume this thin means price can reprice sharply on a single forecast update or a large position. The liquidity depth is reasonable for a contract this close to resolution, but do not treat the current 57% as a settled consensus. One NWS forecast revision before midnight on May 16 could move this 10 points in either direction.

• The 1-hour and 24-hour price change are identical at +24.5%, confirming the move happened in a compressed window and has not reversed.
• The trend score of 85.12 places this contract in the top tier of short-term momentum, unusual for a temperature band market.
• Total volume of $10,299 is below $1 million, meaning thin liquidity amplifies price sensitivity to new forecast data.
• The 57% YES / 43% NO split is narrow enough that a single adverse model run flips the directional lean.
• No whale trades are present in this market, so the momentum signal is distributed across smaller positions rather than driven by one large bet.

Lines Analysis: Miami’s Overnight Low and What Moves It

The case for 78-79°F rests on Miami’s climatological baseline for mid-May. NOAA historical data for Miami International Airport shows average overnight lows in the 74-78°F range for the second half of May, with warmer readings more common as the month progresses and Atlantic sea surface temperatures warm. A reading of 78-79°F on May 17 is climatologically plausible and sits near the upper end of the historical average, consistent with current La Nina to neutral transition conditions that tend to produce warmer overnight lows across South Florida.

The challenge for this outcome is the precision required. A temperature band market is not asking whether it will be warm. It is asking whether the reading lands in a specific two-degree window. The National Weather Service Miami forecast office publishes hourly observations from Miami International Airport and Miami Opa-Locka Airport. If early morning hours on May 17 show persistent cloud cover suppressing radiative cooling, the low could hold at 80°F or above. If a brief dry air intrusion from the northwest occurs overnight, the low could slip to 76-77°F. Neither scenario is unlikely.

Signals to monitor before resolution:

• National Weather Service Miami 18Z and 00Z model runs on May 16 will tighten the overnight low forecast range and directly reprice this contract.
• Surface dewpoint observations at Miami International Airport above 72°F support a warmer overnight low, favoring 80°F or above outcomes.
• Any frontal boundary position shift in the National Weather Service mesoscale analysis for South Florida would immediately affect the temperature band distribution.
• NOAA’s Climate Prediction Center short-range outlooks for May 16-17 are the highest-authority signal available before resolution.
• Wind direction at Miami Executive Airport: onshore southerly flow keeps overnight lows elevated; any westerly component accelerates cooling toward the 76-77°F band.

At $10,299 in total volume, this market is priced by a small number of participants tracking the same NWS data. The 57% probability reflects reasonable meteorological confidence, not certainty. Here’s what the measurements are telling us: mid-May Miami overnight lows cluster near 78°F on average, and the current forecast is consistent with that baseline. The data doesn’t care about the politics of prediction markets. It favors the 78-79°F outcome modestly, but the two-degree precision requirement keeps this genuinely competitive through resolution.

LINES VERDICT

Narrow Meteorological Consensus

Miami’s mid-May climatology supports a 78-79°F overnight low as the most probable single outcome, and the sharp 24-hour momentum surge suggests recent NWS model runs have tightened in that direction.

What the market says: Fifty-seven percent of market capital is behind 78-79°F as of May 17, 2026 at 01:10 AM, reflecting a modest but real meteorological edge. Thin volume means this price can shift meaningfully on a single forecast update before the noon resolution cutoff.

Key unknown: The National Weather Service Miami 00Z model run on May 17 is the single most important data point before resolution. If that run places the overnight low at 77°F or 80°F with low model spread, this contract reprices fast.

Scientific Context

Miami’s overnight lows in mid-May are governed primarily by sea surface temperature in Biscayne Bay and the adjacent Atlantic, prevailing trade wind patterns, and cloud cover from the Intertropical Convergence Zone. NOAA historical records for Miami International Airport show that May overnight lows have trended roughly 1-2°F warmer over the past three decades, consistent with broader Atlantic basin warming. For a single-day contract, that long-term trend matters less than the 48-hour synoptic pattern. The market is pricing uncertainty, not science, in the sense that the science of Miami’s climate clearly supports warm overnight temperatures in May. The uncertainty is entirely about the two-degree precision of the band. Any NWS forecast product narrowing the uncertainty interval before noon on May 17 will be the direct catalyst for the final price movement in this contract.

Frequently Asked Questions

• What does 57% probability mean here? It means the market assigns a 57-in-100 chance that Miami’s official overnight low on May 17 lands between 78°F and 79°F. It is not a guarantee, and that edge is narrow enough to flip on a single forecast revision.
• What happens if the overnight low is 76°F? The 78-79°F contract does not pay out. The 76-77°F outcome band receives the winning settlement instead. Adjacent bands are the primary risk to the current leading outcome.
• What data release or event would move this price most? The National Weather Service Miami overnight forecast update, specifically the 00Z model run on May 17, is the single most price-sensitive data point before the noon resolution cutoff.
• When does this contract resolve? Resolution is set for May 17, 2026 at 12:00 PM. The overnight low measurement used for resolution will reflect official NOAA surface observation data for Miami through that cutoff.
• Is volume high enough to trust this price? Total volume is $10,299, well below $1 million. Liquidity is $43,243, which provides some depth, but thin volume means a single large position or a new forecast print can move the price sharply before resolution.

This analysis reflects market conditions as of 2026-05-17 01:10:25. Prediction market probabilities are volatile and shift as new data and regulatory decisions emerge, especially as the 2026-05-17 12:00:00 resolution date approaches. Lines.com does not accept bets or provide financial or gambling advice. All market outcomes are uncertain.