Seattle's highest temperature on May 19, 2026 is the subject of this daily weather prediction market. The event is objectively resolvable: NOAA weather stations will record the precise maximum temperature that day, eliminating all ambiguity about the outcome. The current market price at 0% YES odds reflects strong consensus among traders that May temperatures in the Pacific Northwest will comfortably exceed the 39°F threshold. Historically, Seattle rarely experiences high temperatures below 40°F in mid-May; the city's 30-year average high temperature in mid-May is around 65°F. A maximum of 39°F or lower would represent a significant late-season freeze event—unusually cold for spring in the region. The 0% odds suggest traders have assessed seasonal climate patterns and hold high confidence that typical warm-spring conditions will prevail through May 19. Some contrarian traders might maintain small YES positions as insurance against the rare possibility of a severe late freeze, but the market consensus strongly weights normal seasonal progression.
What factors could move this market?
Seattle's position in the Pacific Northwest, with its maritime climate moderated by the Pacific Ocean, creates a relatively stable temperature regime during spring. The Puget Sound's proximity helps regulate coastal temperatures, preventing extreme swings common in continental climates. May 19 falls well into spring's established pattern, after the spring equinox (March 20) and typically with increasing daylight and solar heating. A high of 39°F would represent not merely a cool day but a hard freeze event—ice forming on surfaces, potential frost damage to gardens, and disruption to vegetation entering peak growing season.
Factors favoring YES (temperatures at or below 39°F) would include: an unusual Arctic air mass penetration down the Pacific coast, a late-season cold front with polar origins, blocking high pressure steering cold air southward, or moisture-laden systems that suppress daytime warming. The Pacific Northwest's spring storms occasionally bring cooler conditions, particularly when systems pull cold air from Canada. However, by mid-May, such events are statistically very rare. In the past 50 years of Seattle temperature records, highs below 40°F in mid-May occur only a handful of times per decade. When they do occur, they're typically associated with specific patterns like an upper-level low-pressure trough or an unusually strong cold high-pressure system.
Factors favoring NO (temperatures above 39°F) include: normal seasonal progression of increasing solar elevation and day length, typical establishment of mild Pacific air masses by late May, warming ocean temperatures moderating coastal air, high-pressure ridging steering warmer air northward, and the climatological reality that mid-May in Seattle averages around 65°F. Spring's trajectory is monotonically toward warmer conditions; brief cold episodes are anomalies superimposed on an underlying warming trend. The maritime influence intensifies as spring progresses, transforming the ocean from a heat sink to a heat source.
Recent weather patterns in the Pacific Northwest have shown normal-to-warm spring progression in 2026 with no indication of unusual late-season freeze threats. Long-range forecasts show increasing confidence in normal-range temperatures as May progresses. The fact that this is a recurring daily market suggests consistent baseline temperature thresholds across Seattle's calendar, with 0% odds indicating the trader base sees 39°F as statistically outside the reasonable range for this particular date.
The 0% market price implies traders view the probability as negligible—less than 0.5% likelihood. This reflects both historical rarity and current meteorological setup. The substantial liquidity ($10,720) despite zero YES volume indicates this is a calibrated, consensus-driven market where traders have settled on near-zero probability for a late May freeze.
What are traders watching for?
National Weather Service official high temperature recording for Seattle on May 19, 2026—the direct resolution metric for this market.
Upper-level atmospheric patterns and jet stream position during mid-May determining whether cold fronts penetrate the Pacific Northwest.
Long-range weather forecasts issued May 12–18 will provide increasing precision on expected highs for the resolution date.
Sea surface temperature anomalies and Pacific Ocean conditions influencing coastal climate moderation of spring air masses.
How does this market resolve?
This market resolves on May 19, 2026 based on the official maximum temperature recorded by the National Weather Service for the Seattle area. YES resolves if the recorded high is 39°F or below; NO resolves if the high is 40°F or above.
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