Number of tornadoes in May 2026?
Short Answer
Both the model and the market overwhelmingly agree that the number of tornadoes in May 2026 will be Above 25, with only minor residual uncertainty.
1. Executive Verdict
- Early May 2026 tornado activity appears well above the historical monthly average.
- Central Illinois and southern Mississippi recorded over 100 tornadoes by May 11.
- Preliminary SPC data indicates 278 tornadoes for May 2026 through April 26.
- SPC preliminary tornado counts show variable revisions from official totals.
- El Niño conditions typically decrease springtime tornado activity in the southern U.S.
- Insufficient current data exists to compare May 2026 to high-activity years.
Who Wins and Why
| Outcome | Market | Model | Why |
|---|---|---|---|
| Above 200 | 66.0% | 66.8% | Significant early May 2026 activity and emerging El Niño conditions suggest an enhanced tornado count. |
| Above 225 | 60.0% | 60.9% | Early May activity suggests a pace well above the historical monthly average of 265 tornadoes. |
| Above 150 | 87.0% | 87.3% | Early May activity with over 100 tornadoes by May 11 indicates a high total for the month. |
| Above 175 | 70.0% | 70.7% | Early May 2026 activity, including over 100 tornadoes by May 11, suggests a heightened total. |
| Above 100 | 88.0% | 98.0% | Early May 2026 activity alone contributed over 100 tornadoes by May 11. |
Current Context
Significant tornado activity in May 2026 is slightly above normal. As of May 13, 2026, the United States has experienced over 530 confirmed tornadoes across 27 states since the start of the year, a pace slightly ahead of normal [^]. By May 9, 2026, the year's total had reached 559 tornadoes [^]. May is historically one of the most active months for tornadoes, with an average of 265 occurring in the U.S. during this month [^][^]. Notable events in May 2026 include an EF1 tornado southeast of Victoria, Texas, on May 1 [^]. A significant outbreak occurred in the Southeastern United States on May 6-7 [^][^], with Mississippi confirming eight tornadoes (including an EF3, an EF2, four EF1s, and two EF0s) that damaged over 400 homes and 21 businesses, injuring 23 people [^][^]. Other tornadoes during this outbreak included an EF2 in Oklahoma, an EF3 in Beggs, Oklahoma (resulting in two fatalities), an EF2 near Prospect, Texas (two injuries), and an EF2 near Willisville, Arkansas (one injury) [^]. On May 9, an EF0 tornado was confirmed in Delco, North Carolina, and another EF0 caused damage in Mississippi [^]. Illinois leads the nation with over 111 confirmed tornadoes by the end of April [^], while Missouri has surpassed its annual average with 41 tornadoes so far in 2026 [^]. Texas, typically a leader, has had a slower start with 20 tornadoes reported this year [^].
Tornado activity is shifting eastward amidst an active weather season. Meteorologists note a potential eastward shift in tornado activity, with an increased likelihood in Illinois, Indiana, and Tennessee [^]. Unusually high temperatures in March and April contributed to an earlier onset of the severe weather season in states like Missouri, as highlighted by state climatologist Zachary Leasor [^]. Experts are currently studying these shifts in tornado patterns, identifying climate change as a potential contributing factor [^]. The 2026 Atlantic Hurricane Season, which officially runs from June 1 to November 30 [^][^], is predicted to be below-average due to anticipated El Niño conditions that typically increase wind shear, suppressing hurricane formation [^][^]. Colorado State University forecasts 13 named storms, 6 hurricanes, and 2 major hurricanes [^][^], while AccuWeather projects 11–16 named storms, with 3–5 expected to directly impact the United States [^]. Experts caution that a lower number of storms does not equate to zero risk, as a single hurricane making landfall can cause significant damage [^][^][^]. The National Hurricane Center has also expanded its forecast cone to better reflect inland impacts of tropical storms and hurricanes [^][^]. NOAA is scheduled to announce its official 2026 Atlantic Hurricane Season Outlook on May 21, 2026 [^].
Regulated prediction markets enable real-money wagers on weather outcomes. Climate and weather prediction markets are legally available in the U.S., regulated by the Commodity Futures Trading Commission (CFTC) [^][^][^]. Platforms such as Kalshi, Robinhood Predictions, and Polymarket allow individuals to place real-money predictions on various climate and weather outcomes, including daily temperatures, precipitation, hurricane landfalls, and tornado counts [^][^][^]. These markets operate on a "Yes" or "No" contract basis, with contract prices reflecting the perceived probability of an event occurring [^][^]. Research suggests that participating in these markets can influence attitudes, enhance knowledge, and increase support for climate policies [^].
2. Market Behavior & Price Dynamics
Historical Price (Probability)
Outcome probability
Date
This market has demonstrated extremely high and stable confidence since its inception. The price has consistently traded in a very narrow band between 95% and 99% probability, indicating a sideways trend with minimal volatility. The market opened at 99%, saw a brief dip to its low of 95% around April 30, and subsequently returned to the 99% level by mid-May. These two price points effectively serve as the support and resistance levels for the contract's entire trading history. The unwavering high price suggests a strong and stable consensus among market participants from the outset.
The price action is firmly anchored by fundamental data. The historical average for May is 265 tornadoes, which makes the probability of the actual number exceeding the likely threshold of this contract extremely high. The brief dip to 95% does not correlate with any specific information in the provided context and may reflect temporary market dynamics rather than a change in outlook. The market's return to 99% aligns with reports of ongoing severe weather activity in May 2026, which reinforces the initial high probability assessment. The total volume of 771 contracts is moderate, but the lack of volume on specific dates suggests that price shifts can occur on thin trading. Overall, market sentiment is one of near-certainty, viewing a "YES" resolution as a foregone conclusion based on historical averages and early-month activity.
3. Significant Price Movements
Notable price changes detected in the chart, along with research into what caused each movement.
📈 May 02, 2026: 9.0pp spike
Price increased from 85.0% to 94.0%
Outcome: Above 125
What happened: The primary driver for the May 02, 2026 price spike cannot be identified from the provided information. All cited tornado activity and reports occurred after the market movement date, with confirmed tornadoes noted on May 6th [^] and broader preliminary data on May 11th [^]. No social media activity from key figures or viral narratives, nor any market structure factors, were identified for May 02, 2026. Therefore, social media was irrelevant in this analysis due to a lack of evidence.
4. Market Data
Contract Snapshot
This market resolves to "Yes" if the preliminary number of tornadoes in May is above 225, and "No" if it is 225 or below. The outcome is verified from the National Oceanic and Atmospheric Administration's (NOAA) preliminary report summary, using the "Storm Reports Legend" to determine the number of tornadoes. The market closes on May 31, 2026, at 11:59 pm EDT, with a projected payout on June 1, 2026.
Available Contracts
Market options and current pricing
| Outcome bucket | Yes (price) | No (price) | Last trade probability |
|---|---|---|---|
| Above 25 | $1.00 | $0.01 | 99% |
| Above 50 | $0.99 | $0.02 | 99% |
| Above 75 | $1.00 | $0.03 | 99% |
| Above 125 | $0.95 | $0.22 | 96% |
| Above 100 | $0.96 | $0.11 | 88% |
| Above 150 | $0.98 | $0.18 | 87% |
| Above 175 | $0.71 | $0.32 | 70% |
| Above 200 | $0.69 | $0.33 | 66% |
| Above 225 | $0.60 | $0.41 | 60% |
| Above 250 | $0.40 | $0.65 | 39% |
| Above 275 | $0.19 | $0.93 | 23% |
Market Discussion
Traders are discussing the potential for a high number of tornadoes in May 2026 and the market's predictability. An argument for "Yes" is based on May 2025 recording 328 tornadoes, implying a similar trend. However, a counter-argument dismisses past year's data as "irrelevant" for predicting future outcomes, leading to no clear consensus.
5. What do long-range models from the Climate Prediction Center (CPC) and ECMWF indicate about storm-conducive atmospheric patterns for the remainder of May 2026?
| Temperature Outlook (May–Jul 2026) | Above-normal favored across much of CONUS, with 60–70% probability over northern/central Great Basin and Rockies [^] |
|---|---|
| El Niño Emergence Probability | 61% chance in May–Jul 2026 [^][^] |
| Precipitation Outlook (May–Jul 2026) | Below-normal from Pacific Northwest to central Great Plains; above-normal for western Alaska and Lower Four Corners/Atlantic Coast [^] |
The Climate Prediction Center (CPC) favors above-normal temperatures, varied precipitation for MJJ 2026. The long-lead outlook for May-June-July 2026 (MJJ 2026) indicates above-normal temperatures across much of the contiguous United States, with probabilities reaching 60–70% in parts of the northern and central Great Basin and Rockies [^]. For precipitation, enhanced probabilities of below-normal precipitation are shown from the Pacific Northwest through the northern and central Intermountain West and Rockies, extending southeastward across parts of the central Great Plains [^]. Conversely, above-normal precipitation is favored for much of western Alaska and portions of the Lower Four Corners and Atlantic Coast into the eastern Gulf [^]. This seasonal outlook is influenced by favored ENSO-neutral conditions through April-June 2026, with an El Niño emergence likely in May-July 2026, carrying a 61% chance of persisting through at least the end of 2026 [^][^].
Neither CPC nor ECMWF directly describe storm-conducive patterns for May 2026. Despite these long-range seasonal forecasts, neither the Climate Prediction Center nor accessible long-range seasonal products from ECMWF offer direct descriptions of storm-conducive atmospheric patterns or tornado-conducive midlatitude patterns for May 2026 [^][^]. Available ECMWF products primarily focus on tropical cyclones, such as SEAS5 tropical storm density anomalies, and do not provide the necessary detail for midlatitude severe weather [^]. Therefore, the current information from either source does not allow for a direct description of storm-conducive atmospheric patterns for the remainder of May 2026.
6. How does the preliminary tornado count through mid-May 2026 compare to the day-by-day pace of historically high-activity years like May 2011 and May 2019?
| May 2026 Preliminary Tornadoes | 2 (as of 26 Apr 2026) [^] |
|---|---|
| SPC STAMTS Latest Data | Through 26 Apr 2026 [^] |
| May 2019 Tornadoes (May 17-30) | 400 [^] |
Sufficient data is unavailable to compare May 2026 tornado counts against historically high-activity years like May 2011 and May 2019. The research findings lack a national cumulative tornado total specifically through mid-May 2026. For instance, the SPC’s STAMTS preliminary tornado-count table, as of its latest issuance, extends only through April 26, 2026, reporting two preliminary tornadoes for May 2026 by that date [^]. Similarly, while a Wikipedia page for May 2026 mentions preliminary tornado counts, the extracted information does not include a cumulative national total through May 13 necessary for a numerical day-by-day comparison [^]. Consequently, a precise day-by-day comparison for May 2026 cannot be performed with the current data [^][^].
Historical high-activity years, like May 2019, show significant contrasts in available data. May 2019 experienced a period of intense activity from May 17 to May 30, with daily totals contributing to 400 total tornadoes during that span [^]. Notably active days included May 27 (60 tornadoes), May 26 (41 tornadoes), and May 29 (41 tornadoes) [^]. However, a comparable cumulative figure for May 2026 through mid-May is not available in the provided research, making a direct comparison against these historical patterns unfeasible [^].
7. How does the geographic distribution of tornadoes in May 2026 thus far compare between the traditional 'Tornado Alley' and the southeastern 'Dixie Alley'?
| National Tornado Count (as of May 11, 2026) | More than 600 (after NWS surveys) [^] |
|---|---|
| Combined Tornadoes (IL and MS hot spots) | Over 100 [^] |
| Numeric Split (Tornado Alley vs. Dixie Alley) | Not officially provided by May 11, 2026 [^] |
Direct regional comparison between tornado alleys is currently unavailable. As of May 11, 2026, official data does not provide a specific numeric breakdown of tornado counts for May 2026 clearly delineating between the traditional "Tornado Alley" and the southeastern "Dixie Alley" regions [^]. However, one secondary source indicates that Dixie Alley, particularly southern Mississippi, represented a significant portion of early-May tornado activity, suggesting its contribution was not minor compared to the Plains [^].
Over 600 tornadoes occurred nationally, with key hotspots identified. By May 11, 2026, National Weather Service (NWS) surveys reported more than 600 tornadoes nationwide [^]. The two primary geographic hotspots for this activity were central Illinois and southern Mississippi, which collectively accounted for over 100 tornadoes [^]. This strong concentration of activity in southern Mississippi suggests a substantial contribution from the Dixie Alley region to the total early-May tornado count [^].
Current data sources lack specific regional aggregations for direct comparison. While state-level or hotspot-level information is available from sources like iWeatherNet and the National Centers for Environmental Information (NCEI/US), these materials do not provide the specific "alley-region" aggregation necessary for a direct quantitative comparison between "Tornado Alley" and "Dixie Alley" [^]. The total May 2026 tornado count is anticipated to be resolved around June 8, 2026, using NCEI's monthly time-series data [^].
8. Based on the last decade of data, what is the typical revision rate between the Storm Prediction Center's (SPC) preliminary reports and NOAA's official end-of-month tornado count?
| May 2024 Downward Revision | 48% (from 536 PREL to 278 ACT) [^] |
|---|---|
| May 2022 Upward Revision | 10% (from 216 PREL to 238 ACT) [^] |
| March 2026 Official Count | 11 tornadoes [^] |
SPC preliminary tornado counts show variable revisions from official totals. Revisions between the Storm Prediction Center's (SPC) preliminary tornado reports and NOAA's official end-of-month counts have demonstrated both downward and upward adjustments over the past decade. A notable example occurred in May 2024, where the SPC's preliminary count of 536 tornadoes was significantly revised downward by 48% to an official count of 278 [^].
Historical data reveals consistent variability in tornado count adjustments. For instance, May 2022 saw the SPC's preliminary report of 216 tornadoes experience a 10% upward revision, leading to a final count of 238 [^]. In contrast, preliminary counts for May 2015 (414) were adjusted downward by 8% to 381 [^], and May 2014's preliminary 150 count was also reduced by 13% to 130 [^]. Based on these specific examples, the available information is insufficient to establish a single typical revision rate for the entire decade.
9. What does recent research from NOAA and academic climatologists suggest about the influence of El Niño conditions on springtime tornado outbreak frequency in the United States?
| El Niño spring tornado activity (S. Central U.S.) | Decreased during March, April, May [^][^][^][^] |
|---|---|
| El Niño February activity (Gulf Coast/Florida) | Potential for activity, an exception to general reduction [^] |
| La Niña tornado frequency | Generally leads to more frequent, stronger tornadoes [^][^][^][^][^] |
El Niño generally decreases springtime tornado activity in the southern U.S. Recent research indicates that El Niño conditions typically lead to a reduction in tornado and hailstorm activity in the southern central United States during March, April, and May [^][^][^][^]. This suppression is primarily due to El Niño weakening the surface winds responsible for transporting warm, moist air from the Gulf of Mexico, a critical ingredient for storm formation, over Texas and surrounding states [^]. As a result, the southern Great Plains often experiences fewer tornadoes during an El Niño spring [^].
El Niño's influence varies by region, timing, and phase transitions. While generally associated with a mild risk of tornado outbreaks across most of the country when persisting into boreal spring, an exception can occur along the Gulf Coast and central Florida in February, where activity might not be reduced [^]. Interestingly, some studies suggest a surprising enhancement in tornado counts for May, both nationwide and in Oklahoma, during El Niño years, though the reasons for this "relationship flip" are still being investigated [^]. Furthermore, the transition out of an El Niño phase, known as a "decaying El Niño," can amplify atmospheric waves, creating conditions conducive to increased tornado formation [^].
La Niña typically increases tornado activity, but outbreaks occur regardless of ENSO. Conversely, La Niña conditions generally have the opposite effect, often resulting in more frequent, and sometimes stronger and longer-lived, tornadoes across regions such as the Ohio Valley, Southeast, and Upper Midwest [^][^][^][^][^]. Despite these seasonal outlooks provided by the El Niño-Southern Oscillation (ENSO), it is crucial to remember that tornado outbreaks can occur in any season and almost anywhere in the United States, irrespective of the specific ENSO phase [^][^].
10. What Could Change the Odds
Key Catalysts
Preliminary data from the SPC indicates 278 tornadoes for May 2026. This figure was part of a table published May 6, 2026, with totals "through 26 Apr 2026," suggesting it is an in-progress preliminary month count [^]. However, the SPC STAMTS file explicitly states that it publishes preliminary and incomplete counts ("PREL") and advises against comparing these preliminary figures with actual counts, meaning the May figure is not final for May 2026 [^].
On Polymarket, a market titled “How many Tornadoes in the US in May?” includes outcome bands such as “260–289” and “290–319.” The “260–289” band is reported as the leading outcome, holding 47% at the time of capture [^] . Trading Odds & Predictions 2026 | Polymarket">[^]. The Wikipedia page “List of United States tornadoes in May 2026” also notes that its list documents confirmed tornadoes and cautions that tornado counts remain preliminary until they are finally published in NOAA/NCEI’s database [^].
Key Dates & Catalysts
- Expiration: June 01, 2026
- Closes: June 01, 2026
11. Decision-Flipping Events
- Trigger: Preliminary data from the SPC indicates 278 tornadoes for May 2026.
- Trigger: This figure was part of a table published May 6, 2026, with totals "through 26 Apr 2026," suggesting it is an in-progress preliminary month count [^] .
- Trigger: However, the SPC STAMTS file explicitly states that it publishes preliminary and incomplete counts ("PREL") and advises against comparing these preliminary figures with actual counts, meaning the May figure is not final for May 2026 [^] .
- Trigger: On Polymarket, a market titled “How many Tornadoes in the US in May?” includes outcome bands such as “260–289” and “290–319.” The “260–289” band is reported as the leading outcome, holding 47% at the time of capture [^] .
13. Historical Resolutions
Historical Resolutions: 20 markets in this series
Outcomes: 15 resolved YES, 5 resolved NO
Recent resolutions:
- KXTORNADO-26APR-300: NO (May 01, 2026)
- KXTORNADO-26APR-75: YES (May 01, 2026)
- KXTORNADO-26APR-50: YES (May 01, 2026)
- KXTORNADO-26APR-275: YES (May 01, 2026)
- KXTORNADO-26APR-250: YES (May 01, 2026)
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