Short Answer

Both the model and the market expect the highest temperature in Washington DC on May 15, 2026, to be between 70° and 71°, with no compelling evidence of mispricing.

1. Market Behavior & Drivers

The price for this market has remained completely static, opening and currently trading at a 29.0% probability. With only two data points and a total of 14 contracts traded, the market shows no discernible trend and extremely low liquidity. This lack of price movement or significant volume suggests minimal trader engagement and a lack of conviction from the few participants. The 29.0% price level is the only one established so far, acting as both the initial support and resistance, though it is not a meaningful technical level given the absence of trading activity.
The current market price of 29.0% suggests that traders see a low probability of the temperature reaching 70°F or higher. This sentiment appears to be influenced by initial forecasts, such as the National Weather Service's prediction of around 69°F, which falls just below the market's resolution threshold. The market has not yet shown a reaction to conflicting data, like a forecast from WeatherShogun for 81°F, or the broader monthly trend which allows for a wide range of temperatures. The flat price action and low volume indicate the market is in a holding pattern, likely awaiting more definitive weather forecasts closer to the resolution date.
  • NWS extended forecast shows high temperatures around 69°F on May 15, 2026.
  • A pattern flip to a ridge is expected, likely bringing highs into the 80sF.
  • ECMWF consistently anticipates warmer-than-average Mid-Atlantic temperatures during May 2026.
  • May's average daily high typically falls between 75-76°F in Washington DC.
  • Bermuda High patterns could cause 78°F or above temperatures through southwest flow.
  • Markets are highly sensitive to short-term weather model runs and forecast changes.

Current Context

Initial forecasts suggest a high temperature of around 69°F for Washington, DC on May 15, 2026. The National Weather Service’s extended forecast indicates high temperatures around 69°F (approximately 21°C) for the day [1]. In contrast, WeatherShogun lists a “Day 81°” forecast for Friday, May 15, 2026 [2]. Based on higher-reliability sources, the prediction of around 69°F appears more probable.
Broader monthly trends support a high in the upper 60s or low 70s. AccuWeather’s May 2026 monthly forecast for Washington, DC indicates that daily high temperatures generally vary significantly throughout the month, ranging from the mid-60s up to the mid-80s [3]. Within this wider forecast envelope, a high in the upper 60s or low 70s on May 15 is plausible. Additionally, other weather forecast pages, including detailed text from the National Weather Service for neighboring days, imply that a cooler, cloudier day around that time is possible, consistent with highs below 75°F and mentioning chances of precipitation [1].
Sources (3)
  1. 1National Weather Serviceforecast.weather.gov
  2. 2Friday, May 15, 2026. Washington, DC - Weather Forecastweathershogun.com
  3. 3Washington, DC Monthly Weather | AccuWeatheraccuweather.com

2. Price Chart

Historical Price (Probability)

Outcome probability
Date

3. Market Data

Contract Snapshot

A "Yes" resolution for the "70° to 71°" range occurs if the maximum temperature recorded at Washington DC on May 15, 2026, is between 70-71° Fahrenheit. A "No" resolution occurs if the temperature falls outside this range, as the event is mutually exclusive.

Trading for this market closes at 11:59 PM local time on May 15, 2026. The official temperature is verified using the National Weather Service's Climatological Report (Daily) for Washington-National (CLIDCA), and traders should note that preliminary NWS data may involve rounding and conversion nuances.

Market Discussion

Washington D.C. on May 15, 2026, is expected to be partly sunny, transitioning to clear skies at night, with a low chance of rain [1][2]. In prediction markets for weather, successful strategies often involve analyzing multiple climate models and identifying market mispricings [3][4]. However, participants should be cautious of long-range forecasts, especially those from social media, as their accuracy significantly decreases beyond 7 to 10 days, and misinformation is common [5][6][7].

Sources (7)
  1. 1Weather information for Washington, DC, USgoogle.com
  2. 2washingtonpost.com
  3. 3medium.com
  4. 4github.com
  5. 5wkyc.com
  6. 6gardenprofessors.com
  7. 7washingtonpost.com

4. What is the historical temperature range for May 15 in Washington D.C. based on NOAA's climate data from the past 30 years (1996-2025)?

Lowest temperature recorded45°F (2002) [1]
Date of lowest temperatureMay 15 [1]
Observation period1996-2025 [1]
Washington D.C. recorded a May 15 low of 45°F. On May 15, the lowest temperature observed in Washington D.C. between 1996 and 2025 was 45°F [1]. This minimum temperature occurred in the year 2002 [1]. This data point establishes the coldest temperature recorded on this specific date within the defined three-decade period.
A complete temperature range for May 15 is unavailable. The provided research does not contain information regarding the highest temperature recorded on May 15 during the 1996-2025 timeframe. As a result, a comprehensive historical temperature range for this particular date in Washington D.C. cannot be fully determined from the currently available facts.
Sources (1)
  1. 1extremeweatherwatch.com

5. How do the long-range May 2026 temperature forecasts for the Mid-Atlantic region from the Climate Prediction Center (CPC) and the European Centre for Medium-Range Weather Forecasts (ECMWF) compare?

ECMWF May 2026 Mid-Atlantic ForecastConsistently warmer-than-average temperatures anticipated [1]
ECMWF Specific TemperaturesHighs reaching into the 80s and 90s for certain periods [1]
CPC May 2026 Forecast EvolutionInitial cool conditions (early May), shifting to above-normal temperatures (late May) [2]
The European Centre for Medium-Range Weather Forecasts (ECMWF) consistently predicted warmer-than-average temperatures for the Mid-Atlantic in May 2026. This outlook was supported by their February 2026 meteorological spring forecast, which indicated a high risk of unusually warm early spring conditions and broader U.S. warmth, encompassing the Mid-Atlantic region [3]. A May 6 ECMWF-related outlook further favored warmer-than-average summer temperatures for the Southeast and Mid-Atlantic [4]. These forecasts specifically highlighted potentially significant warmth, with temperatures several degrees above normal and reaching into the 80s and 90s during certain periods, although brief interruptions by Canadian cold fronts were anticipated [1].
In contrast, the Climate Prediction Center (CPC) forecasts for May 2026 evolved from cooler to warmer conditions. Earlier discussions referencing CPC in late April 2026 suggested "cool and wet" conditions for early May [5], with a May 12-16, 2026, outlook mentioning near to below-normal temperatures for the eastern half of the country [2]. However, the CPC's 6-10 day outlook, valid from May 17-21, 2026, shifted to favor above-normal temperatures across most of the contiguous U.S., with the most intense heat concentrated in the Southeast, likely including the Mid-Atlantic [2]. Similarly, the CPC's Week-2 Hazards Outlook, valid from May 21-27, 2026, anticipated an increased likelihood of above-normal temperatures with "possible heat lingering" on the East Coast [6].
Sources (6)
  1. 1substack.comweather.substack.com
  2. 2unl.edudroughtmonitor.unl.edu
  3. 3climateimpactcompany.com
  4. 4washingtonpost.com
  5. 5americanwx.com
  6. 6noaa.govcpc.ncep.noaa.gov

6. What specific synoptic weather patterns, such as a 'Bermuda High,' would need to occur in mid-May 2026 to cause a high temperature of 78°F or above in DC?

Target Temperature for Mid-May 202678°F or above [1]
DC May Average High Temperature~75°F [2]
Expected Highs Mid-May 202680sF in the May 15 vicinity [3][4]
Achieving 78°F in DC mid-May requires specific weather patterns. For Washington D.C. to experience a high temperature of 78°F or above in mid-May 2026, particular synoptic weather patterns are necessary, including the presence of a Bermuda High and an upper-level ridge. This temperature represents a +3°F anomaly compared to D.C.'s average May high of approximately 75°F, a condition that typically results from the influence of such weather systems [2].
A Bermuda High and upper-level ridge create a warming air flow. The Bermuda High, a semi-permanent subtropical high-pressure system situated near Bermuda, can extend its western influence to cause significant heat in D.C. through a southwest flow of air, potentially leading to temperatures of 80°F or higher [1][5][6][7][8]. The southerly winds associated with this high's circulation would transport moisture from the Gulf, further contributing to elevated temperatures under sunny skies [5][7]. Concurrently, an upper-level ridge positioned over the eastern United States would build 500mb heights, a pattern that induces warm air advection and subsidence, resulting in clear conditions [3].
Forecasts indicate these conditions are likely for mid-May 2026. For mid-May 2026, a "pattern flip" to a ridge is anticipated, with high temperatures in Washington D.C. projected to reach the 80sF around May 15 [3][4]. This expected synoptic setup would provide the necessary environment to reach or surpass the target temperature of 78°F [2].
Sources (8)
  1. 1The Bermuda High The Outside Storynorthernwoodlands.org
  2. 2Wide World of Weather: DC’s chilly start to Maywideworldofweather.blogspot.com
  3. 3Pattern Flip Incoming: Northeast Goes From Cool and Rainy to 90°F+ Heat by Sunday - Climate Cosmosclimatecosmos.com
  4. 4Friday, May 15, 2026. Washington, DC - Weather Forecastweathershogun.com
  5. 5‘Bermuda High’ already well-developed, factors into brand new warm summer forecastmlive.com
  6. 6Azores High - Wikipediawikipedia.org
  7. 7WEATHER BLOG: What is the Bermuda High?wrdw.com
  8. 8Wx Watch: Bermuda Blockingaopa.org

7. Which specific weather station, typically Reagan National Airport (DCA), serves as the official source for Washington D.C. temperature records, and are there known microclimate biases affecting its readings?

Official D.C. Temperature Record SourceRonald Reagan Washington National Airport (DCA) [1][2]
DCA Station Active From1936 to present [3]
Urban Heat Island Effect on Nights10-15°F warmer compared to suburban areas [4]
Ronald Reagan Washington National Airport is D.C.'s official temperature record source. This station, identified as NCEI GHCND:USW00013743, serves as the primary location for Washington D.C.'s temperature records [1][2]. It has been operational since 1936 [3] and officially assumed the role of D.C.'s primary observation point on July 1, 1945, succeeding a previous downtown site [1][2]. For temperature prediction markets, the Weather Underground KDCA station is the designated source for resolving outcomes [5][6].
Microclimate biases significantly influence temperature readings at DCA. The station's readings are known to be affected by local environmental factors. In 2015, The Washington Post reported that DCA's temperatures were consistently 2.2°F warmer than Dulles since 2014, with potential causes including sensor problems or urban influences [7]. Furthermore, an urban heat island effect at DCA contributes to substantially higher low temperatures, resulting in nights that are 10-15°F warmer compared to nearby suburban regions, though this effect has less impact on high temperatures [4].
Sources (7)
  1. 1National Weather Serviceforecast.weather.gov
  2. 2Ronald Reagan Washington National Airporten.wikipedia.org
  3. 3Daily Summaries Station Details: WASHINGTON REAGAN NATIONAL AIRPORT, VA US, GHCND:USW00013743 | Climate Data Online (CDO) | National Climatic Data Center (NCDC)ncdc.noaa.gov
  4. 42001 Washington, D.C. Ronald Reagan National Airport (DCA) | Encyclopedia.comencyclopedia.com
  5. 5March 15, 2026: Washington DC Daily Temperature High March 15 2026 Prediction Marketrobinhood.com
  6. 6May 11, 2026: Washington DC Daily Temperature High May 11 2026 Prediction Marketrobinhood.com
  7. 7Is D.C.’s weather station reading way too hot?washingtonpost.com

8. What is the projected status of the El Niño-Southern Oscillation (ENSO) for Spring 2026, and how could it influence May temperatures in Washington D.C.?

ENSO-neutral chance (April-June 2026)80% (NOAA CPC) [1][2]
El Niño chance (May-July 2026)61% (NOAA CPC) [1][2]
El Niño probability (IRI, April-June)70% [3]
El Niño projections for Spring 2026 show varied but strengthening consensus. The National Oceanic and Atmospheric Administration's (NOAA) Climate Prediction Center forecasts an 80% chance of ENSO-neutral conditions for April-June 2026, alongside a 61% probability of El Niño for May-July 2026 [1][2]. In contrast, the International Research Institute for Climate and Society (IRI) indicates a 70% likelihood of El Niño for April-June, with this probability rising to 88-94% later in 2026 [3]. A multi-model ensemble from the World Meteorological Organization (WMO) further supports this trend, suggesting rapid warming in the Niño 3.4 region and high confidence in an El Niño onset by May-July [4].
El Niño's influence on Washington D.C. May temperatures is generally subtle. Historically, El Niño often leads to warmer and drier conditions across the northern and eastern United States during transitional seasons [5][6][7]. However, its specific effects during the spring are described as muted compared to other seasons [5][6][7]. Separately, Washington D.C. has already experienced significant temperature volatility during spring 2026 under neutral ENSO conditions, with these fluctuations attributed to a current transition phase [8][9].
Sources (9)
  1. 1Climate Prediction Center: ENSO Diagnostic Discussioncpc.ncep.noaa.gov
  2. 2https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdfcpc.ncep.noaa.gov
  3. 3IRI – International Research Institute for Climate and Society | April 2026 Quick Lookiri.columbia.edu
  4. 4Global Seasonal Climate Update for May-June-July 2026public.wmo.int
  5. 5Strongest El Niño on record may be coming in 2026bostonglobe.com
  6. 6Why Does El Niño Affect Summer Weather Significantly Less Than Winter? | Weather.comweather.com
  7. 7Super El Niño Increasingly Likely, Could Be Record Strong | Weather.comweather.com
  8. 8Weather Blog | Is ENSO behind the wacky weather this spring in the DMV? | DC News Nowdcnewsnow.com
  9. 9Washington DC on track for most volatile temperature year since 1959williamangel.net

9. What Could Change the Odds

Key Catalysts

Hotter-than-average temperatures can lead to increased demand for electricity for air conditioning, potentially driving up energy futures prices (bullish) [1]. Conversely, severe weather can suppress sales (bearish) [1]. Daily high temperature markets are highly sensitive to short-term weather model runs, with price shifts occurring rapidly based on changes in forecasted conditions like wind direction or cloud cover [2].
Extreme weather events such as droughts, floods, or unseasonal freezes can drastically impact crop yields, influencing commodity prices (e.g., corn, wheat, soy) and the stock performance of agricultural companies [1]. The anticipation of severe weather events (e.g., hurricanes, wildfires) can directly affect the insurance industry through increased claims, potentially leading to bearish outlooks for insurer stock prices [1].

Key Dates & Catalysts

  • Strike Date: May 16, 2026
  • Expiration: May 22, 2026
  • Closes: May 16, 2026
Sources (2)
  1. 1openweather.co.uk
  2. 2bettingusa.com

11. Historical Resolutions

Historical Resolutions: 20 markets in this series

Outcomes: 3 resolved YES, 17 resolved NO

Recent resolutions:

  • KXHIGHTDC-26MAY13-T78: NO (May 14, 2026)
  • KXHIGHTDC-26MAY13-T71: NO (May 14, 2026)
  • KXHIGHTDC-26MAY13-B77.5: YES (May 14, 2026)
  • KXHIGHTDC-26MAY13-B75.5: NO (May 14, 2026)
  • KXHIGHTDC-26MAY13-B73.5: NO (May 14, 2026)