# Rain in Houston in May 2026? In May 2026 Updated: May 1, 2026 Category: Climate and Weather Tags: Snow and rain HTML: /markets/climate-and-weather/snow-and-rain/rain-in-houston-in-may-2026/ ## Short Answer **Key takeaway.** Both the **model** and the **market** expect rain above 1 inch in Houston in May 2026, with no compelling evidence of mispricing. ## Key Claims (January 2026) **- - Houston's extreme precipitation events show a significant increasing trend.** - Climate models lack long-range ENSO forecast skill for May 2026. - Specific May 2026 Western Gulf SST projections are currently unavailable. - Influence of tropical systems on Houston's wettest Mays is unclear. - May precipitation forecasts for Southeast Texas stabilize closer to date. ### Why This Matters (GEO) - AI agents extract claims, not arguments. - Improves citation probability in summaries and answer cards. - Enables fact stitching across multiple sources. ## Executive Verdict **Key takeaway.** **Market** is 0.5 percentage points above Octagon's **98.5%** **model** despite Houston's increasing extreme precipitation trends. ### Who Wins and Why | Outcome | Market | Model | Why | | --- | --- | --- | --- | | Above 7 inches | 46.0% | 38.3% | Market higher by 7.7pp | | Above 4 inches | 87.0% | 82.0% | Market higher by 5.0pp | | Above 5 inches | 74.0% | 66.3% | Market higher by 7.7pp | ## Model vs Market | Outcome | Market Probability | Octagon Model Probability | | --- | --- | --- | | Above 7 inches | 46.0% | 38.3% | | Above 4 inches | 87.0% | 82.0% | | Above 5 inches | 74.0% | 66.3% | | Above 6 inches | 64.0% | 55.5% | | Above 3 inches | 96.0% | 94.2% | | Above 2 inches | 98.0% | 97.1% | | Above 1 inch | 99.0% | 98.5% | - Expiration: June 1, 2026 ## Market Behavior & Price Dynamics Based on the provided data, this market has exhibited no price movement since its inception. The contract opened at a 99.0% probability for a "YES" resolution and has remained at that level. With only two data points recorded, the overall trend is completely flat. There have been no significant price spikes, drops, or any volatility to analyze. The absence of price changes indicates a static market, and as there is no additional context provided, there are no external events to correlate with the chart's stability. The trading volume for this market is exceptionally low, with a total of only two contracts traded. This minimal activity suggests very little market participation and a lack of conviction from a broader base of traders. Such low volume means the current price has not been challenged or validated by significant trading, and it may only reflect the opinion of one or two initial participants. Due to the complete lack of price fluctuation, no support or resistance levels can be identified; the 99.0% mark is the only price at which the contract has ever traded. The market sentiment, as reflected by the price, indicates an extremely high expectation that it will rain in Houston in May 2026. However, this apparent consensus is based on almost nonexistent trading volume, making the market highly illiquid and its price a potentially unreliable indicator of widespread belief. ## Significant Price Movements #### 📈 May 01, 2026: 14.0pp spike Price increased from 60.0% to 74.0% **Outcome:** Above 5 inches **What happened:** No supporting research available for this anomaly. ## Contract Snapshot This market resolves to YES if the total precipitation at CLIHOU in Houston during May 2026 is strictly greater than 7 inches; otherwise, it resolves to NO. The market opens on May 1, 2026, 10:24am EDT, closing early if the event occurs, or by May 31, 2026, 11:59pm EDT, with payouts projected 30 minutes after closing. Resolution is verified using the first NWS Climatological Report Houston (for Houston-Hobby, TX) containing full-month data, and traders should be aware of potential rounding nuances in preliminary data. ## Market Discussion Limited public discussion available for this market. ## Market Data | Contract | Yes Bid | Yes Ask | Last Price | Volume | Open Interest | | --- | --- | --- | --- | --- | --- | | Above 1 inch | 98% | 99% | 99% | $2 | $2 | | Above 2 inches | 98% | 99% | 98% | $3 | $3 | | Above 3 inches | 91% | 98% | 96% | $20 | $10 | | Above 4 inches | 87% | 94% | 87% | $2,535 | $2,442 | | Above 5 inches | 73% | 78% | 74% | $878 | $672 | | Above 6 inches | 55% | 63% | 64% | $80 | $50 | | Above 7 inches | 39% | 45% | 46% | $3,092 | $2,014 | ## What is the ENSO Forecast for Houston's May 2026 Rainfall? ENSO Forecast Spring 2026 | Not available due to limited model skill beyond 6-9 months [[^]](https://cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/strengths.php) | ENSO Correlation May Rainfall Houston | Not strong [[^]](https://www.houstonchronicle.com/news/houston-weather/article/does-el-nino-bring-more-hail-to-texas-22082088.php) | Normal May Precipitation Houston | 4.93 inches (1991-2020 averages) [[^]](https://www.weather.gov/hgx/climate_iah_normals_may) | **Climate models lack long-range El Niño-Southern Oscillation (ENSO) forecast skill** Climate models lack long-range El Niño-Southern Oscillation (ENSO) forecast skill. Major global climate models, including those from NOAA and ECMWF, generally show decreasing reliability in predicting the ENSO state beyond 6-9 months [[^]](https://cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/strengths.php). As a result, the provided research does not contain a specific consensus forecast for the ENSO state during Spring 2026, which includes May 2026. Reliable long-range predictions for specific ENSO phases two years into the future are typically not available from these sources, which primarily focus on near-term to medium-term outlooks [[^]](https://cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/strengths.php). ENSO phases show weak correlation with Houston's May rainfall. The available sources indicate that the connection between ENSO phases and spring/summer rainfall in Houston, Texas, is not strong, unlike the more pronounced correlation observed during the winter months [[^]](https://www.houstonchronicle.com/news/houston-weather/article/does-el-nino-bring-more-hail-to-texas-22082088.php). Consequently, the research does not offer specific historical median May rainfall figures for Houston categorized by strong or weak El Niño or La Niña phases since 1950. For general reference, the normal monthly precipitation for Houston in May is 4.93 inches, based on 1991-2020 averages [[^]](https://www.weather.gov/hgx/climate_iah_normals_may). ## Can Western Gulf of Mexico SST for May 2026 be forecasted? Typical SST Forecast Horizon | Beyond 9-12 months for specific regional anomalies [[^]](https://www.cpc.ncep.noaa.gov/products/NMME/seasanom.shtml) | Wettest May Houston Hobby Airport | 18.67 inches (May 2015) [[^]](https://www.weather.gov/hgx/climate_hou_top10_may) | Gulf SST and Extreme Precipitation Link | Warm SSTs linked to increased moisture and extreme events [[^]](https://repository.library.noaa.gov/view/noaa/57196) | **Specific May 2026 Western Gulf SST projections are currently unavailable** Specific May 2026 Western Gulf SST projections are currently unavailable. Detailed regional sea surface temperature (SST) anomaly projections for the Western Gulf of Mexico in May 2026 extend beyond the typical forecast horizon of publicly available climate models [[^]](https://www.cpc.ncep.noaa.gov/products/NMME/seasanom.shtml). Forecasts from sources such as the Climate Prediction Center generally provide outlooks for only several months, often up to 9-12 months for broader climate patterns like ENSO, making specific monthly regional SST anomaly values for a period nearly two years in the future generally not accessible [[^]](https://www.cpc.ncep.noaa.gov/products/NMME/seasanom.shtml). While current observations may indicate above-average SSTs across parts of the Gulf of Mexico, these represent recent conditions and are not projections for May 2026 [[^]](https://www.threads.com/@floridatropics1/post/DW-PLQlDJY8/looking-at-sst-anomalies-most-of-the-gulf-continues-to-be-above-average-will). Warm Gulf SSTs correlate with increased extreme Houston rainfall. While direct forecasts for May 2026 are not available, historical climate analysis shows a strong association between anomalously warm Gulf of Mexico SSTs during late spring and increased moisture availability, which contributes to extreme precipitation events along the U.S. Gulf Coast [[^]](https://repository.library.noaa.gov/view/noaa/57196). This historical pattern includes some of Houston's wettest Mays on record; for example, May 2015 recorded 18.67 inches of rain at Hobby Airport, and May 1990 saw 14.65 inches [[^]](https://www.weather.gov/hgx/climate_hou_top10_may). Scientific consensus suggests that periods of extreme rainfall are often linked to warmer-than-average Gulf waters, which fuel these heavy precipitation events [[^]](https://repository.library.noaa.gov/view/noaa/57196). ## What are the Trends in Houston's May Precipitation and Extreme Events? Extreme Precipitation Trend | Statistically significant increase in frequency and magnitude [[^]](https://ui.adsabs.harvard.edu/abs/2022AMS...10288715S/abstract) | Total Monthly May Rainfall Trend | Not explicitly detailed as a statistically significant linear trend [[^]](https://ui.adsabs.harvard.edu/abs/2022AMS...10288715S/abstract) | May >1 Inch Rain Days Frequency | Specific statistically significant linear trend since 1970 not explicitly detailed [[^]](https://ui.adsabs.harvard.edu/abs/2022AMS...10288715S/abstract) | **Extreme precipitation events in Houston show a significant increasing trend** Extreme precipitation events in Houston show a significant increasing trend. Research indicates a statistically significant upward trend in both the frequency and magnitude of extreme precipitation events within the Houston area [[^]](https://ui.adsabs.harvard.edu/abs/2022AMS...10288715S/abstract). This encompasses an observed increase in heavy precipitation events, often defined by high percentiles of daily rainfall, which would include days experiencing more than 1 inch of rain [[^]](https://link.springer.com/content/pdf/10.1007/s11069-020-04235-x.pdf?error=cookies_not_supported&code=90f68aeb-dd72-461f-a4b1-38a64fc8e781). These findings collectively suggest a general pattern of more intense rainfall occurring over time in the region [[^]](https://ui.adsabs.harvard.edu/abs/2022AMS...10288715S/abstract). Specific May rainfall trends lack definitive data in current research. While precipitation patterns are changing across Southeast Texas [[^]](https://springerplus.springeropen.com/counter/pdf/10.1186/s40064-015-1245-7.pdf), the provided research abstracts and descriptions do not offer specific data or a definitive finding on a statistically significant linear trend for the total amount of rainfall specifically for the month of May since 1970 [[^]](https://ui.adsabs.harvard.edu/abs/2022AMS...10288715S/abstract). The available sources focus more on extreme events rather than an overall linear trend in monthly totals or the May-specific frequency of days experiencing more than 1 inch of rain [[^]](https://ui.adsabs.harvard.edu/abs/2022AMS...10288715S/abstract). ## What Influences Houston's Wettest Mays & 2026 Hurricane Season Forecasts? Tropical Influence on Houston's Wettest Mays | Undetermined from provided sources [[^]](https://www.weather.gov/hgx/climate_hou_top10_may) | CSU 2026 Atlantic Hurricane Season Forecast | Somewhat below-normal/average [[^]](https://www.artemis.bm/news/csu-forecasts-somewhat-below-normal-2026-atlantic-hurricane-season/) | NOAA 2026 Atlantic Hurricane Season Forecast | Not yet available in provided research [[^]](https://www.noaa.gov/news-release/noaa-predicts-above-normal-2025-atlantic-hurricane-season) | **The influence of tropical systems on Houston's wettest Mays is unclear** The influence of tropical systems on Houston's wettest Mays is unclear. The provided research lists the ten wettest Mays for both Houston Hobby Airport and Houston George Bush Intercontinental Airport, including specific dates and rainfall totals [[^]](https://www.weather.gov/hgx/climate_hou_top10_may). However, these sources do not detail the meteorological origins of these heavy rainfall events. Therefore, it is not possible to determine what percentage of these events were directly caused by early-season tropical disturbances or cyclones in the Gulf of Mexico. CSU anticipates a below-normal 2026 Atlantic hurricane season. Colorado State University (CSU) researchers have issued an initial forecast predicting a "somewhat below-normal" or "somewhat below-average" level of activity for the 2026 Atlantic hurricane season [[^]](https://www.artemis.bm/news/csu-forecasts-somewhat-below-normal-2026-atlantic-hurricane-season/). In contrast, initial forecasts from the National Oceanic and Atmospheric Administration (NOAA) for the 2026 Atlantic hurricane season are not available within the provided research. NOAA's current updates predominantly focus on the 2025 season, which is projected to have "above-normal" activity [[^]](https://www.noaa.gov/news-release/noaa-predicts-above-normal-2025-atlantic-hurricane-season). ## When Do Southeast Texas Precipitation Forecasts Stabilize and What Indicates Dry Conditions? Forecast Stabilization Period | Q1 2026 (January-March 2026) [[^]](https://journals.ametsoc.org/view/journals/hydr/15/2/jhm-d-13-072_1.xml) | Highest Stability Forecasts | Forecasts issued closest to May 2026 (e.g., April 2026) [[^]](https://repository.library.noaa.gov/view/noaa/15240) | Indicator for Drier May | Strong or developing La Niña through spring 2026 [[^]](https://journals.ametsoc.org/view/journals/hydr/15/2/jhm-d-13-072_1.xml) | **Forecast stabilization and consensus increase closer to the target May** Forecast stabilization and consensus increase closer to the target May. For a May precipitation anomaly forecast in Southeast Texas, North American Multi-**Model** Ensemble (NMME) models would typically show increasing stabilization and stronger consensus during Q1 2026 (January-March 2026), corresponding to forecasts issued with 2 to 4 months lead time from the target month of May [[^]](https://journals.ametsoc.org/view/journals/hydr/15/2/jhm-d-13-072_1.xml). However, the skill of these forecasts for precipitation in the southeastern U.S. is generally modest, particularly for forecasts initialized during the spring months [[^]](https://journals.ametsoc.org/view/journals/hydr/15/2/jhm-d-13-072_1.xml). Consequently, the highest level of stability and consensus would generally be observed in forecasts issued closest to May 2026, such as those made in April 2026 with a 1-month lead [[^]](https://repository.library.noaa.gov/view/noaa/15240). La Niña conditions are crucial for indicating a drier May. To indicate a significantly drier-than-average May in Southeast Texas, NMME models would need to project specific large-scale atmospheric patterns. The El Niño-Southern Oscillation (ENSO) is recognized as the primary driver of seasonal climate variability in North America [[^]](https://www.chc.ucsb.edu/monitoring/nmme). A strong or developing La Niña event persisting through spring 2026 would be the most significant indicator for drier conditions, as La Niña phases are typically associated with below-average precipitation across the western and central portions of the Southeast U.S., including Texas, especially during cooler seasons and into spring [[^]](https://journals.ametsoc.org/view/journals/hydr/15/2/jhm-d-13-072_1.xml). ## What Could Change the Odds **Key takeaway.** Catalyst analysis unavailable. ## Key Dates & Catalysts - **Expiration:** June 16, 2026 - **Closes:** June 01, 2026 ## Decision-Flipping Events - Catalyst analysis unavailable. ## Related Research Reports - [EU meets its 2030 climate goals?](/markets/climate-and-weather/climate-change/eu-meets-its-2030-climate-goals/) - [Will there be an at least 8.0 magnitude earthquake in California before 2035?](/markets/climate-and-weather/will-there-be-an-at-least-8-0-magnitude-earthquake-in-california-before-2035/) - [8.0 magnitude earthquake in Japan before 2030?](/markets/climate-and-weather/8-0-magnitude-earthquake-in-japan-before-2030/) - [Will a supervolcano erupt before 2050?](/markets/climate-and-weather/will-a-supervolcano-erupt-before-2050/) ## Historical Resolutions **Historical Resolutions:** 20 markets in this series **Outcomes:** 7 resolved YES, 13 resolved NO **Recent resolutions:** - KXRAINHOUM-26APR-7: NO (May 01, 2026) - KXRAINHOUM-26APR-6: NO (May 01, 2026) - KXRAINHOUM-26APR-5: YES (May 01, 2026) - KXRAINHOUM-26APR-4: YES (May 01, 2026) - KXRAINHOUM-26APR-3: YES (May 01, 2026) ## Disclaimer This content is for informational and educational purposes only and does not constitute financial, investment, legal, or trading advice. Prediction markets involve risk of loss. Past performance does not guarantee future results. We are not affiliated with Kalshi or any prediction market platform. Market data may be delayed or incomplete. ### Data Sources & Model Transparency **Data Sources:** Octagon Deep Research aggregates information from multiple sources including news, filings, and market data. **Freshness:** Analysis is generated periodically and may not reflect the latest developments. Verify critical information from primary sources. ## Attribution Policy When quoting, summarizing, or reproducing Octagon AI content, attribute it to Octagon AI and link to the Octagon source URL: https://octagonai.co/markets/climate-and-weather/snow-and-rain/rain-in-houston-in-may-2026 If a specific page was used, cite that page rather than only the site homepage.