May 2024 Tropical Cyclones Report

Summary

Five named storms occurred across the globe in May, which was above the 1991-2020 average of four. Two of those reached tropical cyclone strength (≥74 mph), and none reached major tropical cyclone strength (≥111 mph). The global accumulated cyclone energy (ACE: an integrated metric of the strength, frequency, and duration of tropical storms) was about 85% of the 1991-2020 average for May.

Two tropical cyclone strength systems occurred globally during the month of May, Tropical Cyclone Hidaya in the South Indian Ocean and Typhoon Ewiniar in the West Pacific. Tropical Cyclone Hidaya (May 1st - May 4th) peaked with winds of 90 mph and a minimum central pressure of 974 mb. Hidaya brought gusty winds and rains to coastal Tanzania as a weakening tropical storm. The other tropical cyclone strength system during May, Typhoon Ewiniar, peaked as a category 2 equivalent storm with winds of 105 mph and a minimum central pressure of 957 mb. Typhoon Ewiniar brought significant impacts to the Philippines and Japan, causing flooding and wind impacts in both countries, displacing thousands of people and resulting in at least seven fatalities.

In addition to Tropical Cyclone Hidaya, two other tropical cyclones occurred in the South Indian Ocean, both of which peaked as tropical storm strength systems. Tropical Storm Ialy peaked as a strong tropical storm with winds of 70 mph and a minimum central pressure of 989 mb. Ialy approached Tanzania but ultimately remained offshore, resulting in minimal impacts. The other storm, an unnamed tropical storm, peaked with winds of 40 mph and a minimum central pressure of 1002 mb. The unnamed tropical storm remained well away from land.

The only other tropical cyclone to occur globally during May was Cyclonic Storm Remal in the North Indian Ocean. Remal peaked as a moderately strong tropical storm with winds of 60 mph and a minimum central pressure of 978 mb. Remal made landfall near the border of India and Bangladesh causing very significant flooding impacts in both countries. Remal was responsible for at least 54 fatalities, while displacing tens of thousands of people.

No storms formed in the southwest Pacific, or the Australian region during May. Additionally, no storms were active in the North Atlantic or East Pacific. The lack of activity is below average, but not uncommon for these basins during the month of May. Typhoon Ewiniar marked the fifth latest start to the West Pacific Typhoon season since reliable records began. Three storms formed in the South Indian Ocean during May, which set a new record.

North Atlantic

No North Atlantic Tropical Cyclones occurred during May 2024.

North Atlantic Tropical Cyclone May Counts

Storm Type	Count	1991-2020 Mean	1981-2024 Rank*	1851-2024 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	0	0.3 (3 in 10 Mays)	11th (tied with 33 other Mays)	2 (1887, 2012, 2020)
Hurricane Winds ≥ 74 mph (64 kts)	0	0.0 (0 in 10 Mays)	1st (tied with 43 other Mays)	1 (1889, 1908, 1951, 1970)
Major Hurricane Winds ≥ 111 mph (96 kts)	0	0.0 (0 in 10 Mays)	1st (tied with 43 other Mays)	0
Accumulated Cyclone Energy ACE×10⁴ kt²	0.0	0.4 (4 in 10 Mays)	11th (tied with 33 other Mays)	16.1 (1951)

North Atlantic Tropical Cyclone Season Counts January-May 2024

Storm Type	Count	1991-2020 Mean	1981-2024 Rank*	1851-2024 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	0	0.5 (5 in 10 seasons)	16th (tied with 28 other seasons)	2 (7 seasons)
Hurricane Winds ≥ 74 mph (64 kts)	0	0.0 (0 in 10 seasons)	2nd (tied with 42 other seasons)	2 (1908)
Major Hurricane Winds ≥ 111 mph (96 kts)	0	0.0 (0 in 10 seasons)	1st (tied with 43 other seasons)	0
Accumulated Cyclone Energy ACE×10⁴ kt²	0.0	0.9 (9 in 10 seasons)	16th (tied with 28 other seasons)	21.6 (1951)

East Pacific

No East Pacific Tropical Cyclones occurred during May 2024.

East Pacific Tropical Cyclone May Counts

Storm Type	Count	1991-2020 Mean	1981-2024 Rank*	1949-2024 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	0	0.7 (7 in 10 Mays)	27th (tied with 17 other Mays)	2 (6 Mays)
Hurricane Winds ≥ 74 mph (64 kts)	0	0.3 (3 in 10 Mays)	14th (tied with 30 other Mays)	1 (16 Mays)
Major Hurricane Winds ≥ 111 mph (96 kts)	0	0.2 (2 in 10 Mays)	6th (tied with 38 other Mays)	1 (5 Mays)
Accumulated Cyclone Energy ACE×10⁴ kt²	0.0	3.1	27th (tied with 17 other Mays)	18.6 (2014)

East Pacific Tropical Cyclone Season Counts January-May 2024

Storm Type	Count	1991-2020 Mean	1981-2024 Rank*	1949-2024 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	0	0.8 (8 in 10 seasons)	30th (tied with 14 other seasons)	2 (7 seasons)
Hurricane Winds ≥ 74 mph (64 kts)	0	0.3 (3 in 10 seasons)	16th (tied with 28 other seasons)	1 (18 seasons)
Major Hurricane Winds ≥ 111 mph (96 kts)	0	0.2 (2 in 10 seasons)	7th (tied with 37 other seasons)	1 (6 seasons)
Accumulated Cyclone Energy ACE×10⁴ kt²	0.0	3.8	30th (tied with 14 other seasons)	18.6 (2014)

West Pacific

May 2024 West Pacific Tropical Cyclones

Name	Maximum CategoryMax Cat	Dates >39 mph	Maximum Sustained Winds	Minimum Central Pressure
Ewiniar	2	May 25May 25-31	105 mph	957 mb

West Pacific Tropical Cyclone May Counts

Storm Type	Count	1991-2020 Mean	1981-2024 Rank*	1945-2024 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	1	1.2	14th (tied with 18 other Mays)	6 (1971)
Typhoon Winds ≥ 74 mph (64 kts)	1	0.7 (7 in 10 Mays)	5th (tied with 20 other Mays)	3 (1971, 2008)
Major Typhoon Winds ≥ 111 mph (96 kts)	0	0.5 (5 in 10 Mays)	18th (tied with 26 other Mays)	2 (1976, 2008, 2015)
Accumulated Cyclone Energy ACE×10⁴ kt²	9.8	13.3	19th	58.9 (2015)

West Pacific Tropical Cyclone Season Counts January-May 2024

Storm Type	Count	1991-2020 Mean	1981-2024 Rank*	1945-2024 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	1	2.8	35th (tied with 5 other seasons)	9 (1971)
Typhoon Winds ≥ 74 mph (64 kts)	1	1.4	19th (tied with 16 other seasons)	5 (2015)
Major Typhoon Winds ≥ 111 mph (96 kts)	0	0.9 (9 in 10 seasons)	29th (tied with 15 other seasons)	4 (2015)
Accumulated Cyclone Energy ACE×10⁴ kt²	9.8	26.5	32nd	108.5 (2015)

North Indian

May 2024 North Indian Tropical Cyclones

Name	Maximum CategoryMax Cat	Dates >39 mph	Maximum Sustained Winds	Minimum Central Pressure
Remal	TS	May 25May 25-27	60 mph	978 mb

North Indian Tropical Cyclone May Counts

Storm Type	Count	1991-2020 Mean	1981-2024 Rank*	1972-2024 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	1	0.9 (9 in 10 Mays)	9th (tied with 20 other Mays)	3 (2010)
Cyclone Winds ≥ 74 mph (64 kts)	0	0.5 (5 in 10 Mays)	21st (tied with 23 other Mays)	2 (2021)
Major Cyclone Winds ≥ 111 mph (96 kts)	0	0.3 (3 in 10 Mays)	13th (tied with 31 other Mays)	1 (12 Mays)
Accumulated Cyclone Energy ACE×10⁴ kt²	1.7	5.2	27th	20.0 (2020)

North Indian Tropical Cyclone Season Counts January-May 2024

Storm Type	Count	1991-2020 Mean	1981-2024 Rank*	1972-2024 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	1	1.2	17th (tied with 18 other seasons)	3 (2010)
Cyclone Winds ≥ 74 mph (64 kts)	0	0.6 (6 in 10 seasons)	23rd (tied with 21 other seasons)	2 (2021)
Major Cyclone Winds ≥ 111 mph (96 kts)	0	0.3 (3 in 10 seasons)	15th (tied with 29 other seasons)	1 (14 seasons)
Accumulated Cyclone Energy ACE×10⁴ kt²	1.7	6.9	30th	22.2 (2019)

South Indian

May 2024 South Indian Tropical Cyclones

Name	Maximum CategoryMax Cat	Dates >39 mph	Maximum Sustained Winds	Minimum Central Pressure
Hidaya	1	May 1May 1-4	90 mph	974 mb
Ialy	TS	May 16May 16-22	70 mph	989 mb
Unnamed	TS	May 19May 19-20	40 mph	1002 mb

South Indian Tropical Cyclone May Counts

Storm Type	Count	1991-2020 Mean	1981-2024 Rank*	1956-2024 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	3	0.3 (3 in 10 Mays)	1st	3† (2024)
Cyclone Winds ≥ 74 mph (64 kts)	1	0.1 (1 in 10 Mays)	1st (tied with 7 other Mays)	1 (8 Mays)
Major Cyclone Winds ≥ 111 mph (96 kts)	0	0.0 (0 in 10 Mays)	2nd (tied with 42 other Mays)	1 (2023)
Accumulated Cyclone Energy ACE×10⁴ kt²	9.7	1.0	2nd	13.0 (2023)
†Previous record 1 (15 Mays)

South Indian Tropical Cyclone Season Counts July 2023-May 2024

Storm Type	Count	1991-2020 Mean	1981-2024 Rank*	1956-2024 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	13	10.4	4th (tied with 4 other seasons)	16 (1997)
Cyclone Winds ≥ 74 mph (64 kts)	5	6.0	26th (tied with 6 other seasons)	11 (2019)
Major Cyclone Winds ≥ 111 mph (96 kts)	2	3.5	29th (tied with 8 other seasons)	9 (2019)
Accumulated Cyclone Energy ACE×10⁴ kt²	70.7	94.1	32nd	186.9 (1994)

Australia

No Australia Tropical Cyclones occurred during May 2024.

Australia Tropical Cyclone May Counts

Storm Type	Count	1991-2020 Mean	1981-2024 Rank*	1956-2024 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	0	0.3 (3 in 10 Mays)	16th (tied with 28 other Mays)	4 (1963)
Tropical Cyclone Winds ≥ 74 mph (64 kts)	0	0.1 (1 in 10 Mays)	4th (tied with 40 other Mays)	2 (1986)
Major Tropical Cyclone Winds ≥ 111 mph (96 kts)	0	0.0 (0 in 10 Mays)	2nd (tied with 42 other Mays)	1 (1997)
Accumulated Cyclone Energy ACE×10⁴ kt²	0.0	0.8 (8 in 10 Mays)	16th (tied with 28 other Mays)	12.6 (1986)

Australia Tropical Cyclone Season Counts July 2023-May 2024

Storm Type	Count	1991-2020 Mean	1981-2024 Rank*	1956-2024 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	10	10.6	25th (tied with 3 other seasons)	19 (1999)
Tropical Cyclone Winds ≥ 74 mph (64 kts)	6	4.8	8th (tied with 6 other seasons)	9 (1992, 1996)
Major Tropical Cyclone Winds ≥ 111 mph (96 kts)	3	2.4	10th (tied with 7 other seasons)	6 (2015)
Accumulated Cyclone Energy ACE×10⁴ kt²	64.1	59.5	14th	111.3 (1999)

Southwest Pacific

No Southwest Pacific Tropical Cyclones occurred during May 2024.

Southwest Pacific Tropical Cyclone May Counts

Storm Type	Count	1991-2020 Mean	1981-2024 Rank*	1956-2024 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	0	0.2 (2 in 10 Mays)	9th (tied with 35 other Mays)	2 (1989, 1997, 2017)
Tropical Cyclone Winds ≥ 74 mph (64 kts)	0	0.1 (1 in 10 Mays)	4th (tied with 40 other Mays)	2 (2017)
Major Tropical Cyclone Winds ≥ 111 mph (96 kts)	0	0.0 (0 in 10 Mays)	2nd (tied with 42 other Mays)	1 (2017)
Accumulated Cyclone Energy ACE×10⁴ kt²	0.0	1.1	9th (tied with 35 other Mays)	28.6 (2017)

Southwest Pacific Tropical Cyclone Season Counts July 2023-May 2024

Storm Type	Count	1991-2020 Mean	1981-2024 Rank*	1956-2024 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	6	6.9	17th (tied with 11 other seasons)	16 (1998)
Tropical Cyclone Winds ≥ 74 mph (64 kts)	2	3.7	29th (tied with 9 other seasons)	10 (1998)
Major Tropical Cyclone Winds ≥ 111 mph (96 kts)	1	1.9	20th (tied with 15 other seasons)	6 (2003)
Accumulated Cyclone Energy ACE×10⁴ kt²	22.4	49.9	33rd	128.8 (1998)

Global

May 2024 Global Tropical Cyclones

Name	Maximum CategoryMax Cat	Dates >39 mph	Maximum Sustained Winds	Minimum Central Pressure
Hidaya	1	May 1May 1-4	90 mph	974 mb
Ialy	TS	May 16May 16-22	70 mph	989 mb
Unnamed	TS	May 19May 19-20	40 mph	1002 mb
Ewiniar	2	May 25May 25-31	105 mph	957 mb
Remal	TS	May 25May 25-27	60 mph	978 mb

Global Tropical Cyclone May Counts

Storm Type	Count	1991-2020 Mean	1981-2024 Rank*	1972-2024 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	5	3.8	8th (tied with 10 other Mays)	7 (5 Mays)
Tropical Cyclone Winds ≥ 74 mph (64 kts)	2	1.8	12th (tied with 11 other Mays)	4 (1986, 1997, 2008, 2015)
Major Tropical Cyclone Winds ≥ 111 mph (96 kts)	0	1.0	29th (tied with 15 other Mays)	3 (2008, 2015, 2023)
Accumulated Cyclone Energy ACE×10⁴ kt²	21.2	24.9	21st	81.6 (2023)

Global Tropical Cyclone Season Counts January-May 2024

Storm Type	Count	1991-2020 Mean	1981-2024 Rank*	1972-2024 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	25	25.0	19th (tied with 8 other seasons)	35 (1986)
Tropical Cyclone Winds ≥ 74 mph (64 kts)	9	13.3	42nd (tied with 1 other season)	19 (1994)
Major Tropical Cyclone Winds ≥ 111 mph (96 kts)	4	7.5	38th (tied with 3 other seasons)	13 (2015)
Accumulated Cyclone Energy ACE×10⁴ kt²	134.2	203.9	37th	325.5 (1994)

Data Description

The data in this report are derived from NCEI's IBTrACS dataset (Knapp et al. 2010; Schreck et al. 2014). IBTrACS tropical cyclone track and intensity data from agencies and sources around the globe. In this report, data from NOAA's National Hurricane Center (NHC) are used for the North Atlantic and East Pacific. The other basins use data from the U.S. Military's Joint Typhoon Warning Center (JTWC).

Historical values use the "best track" data that have been analyzed by forecasters after the season using all available data. Operational procedures and observing systems have changed with time and between regions, which makes these data heterogeneous. Intensity data are generally the most reliable since the early 1970s in the Atlantic (Landsea and Franklin 2013) and since the mid-1980s in other regions (Chu et al. 2002). The number of short-lived storms (≤2 days) has also increased since around 2000 due to improvements in observations and analysis techniques (Landsea et al. 2010).

Values for the current year are provisional values from the operational forecast advisories. IBTrACS obtains these from NCEP's TC Vitals, the NCAR Tropical Cyclone Guidance Project, and NHC provisional data. These values are subject to change during the post-season best track analysis. They also only include 6-hourly storm fixes, which means they may miss special advisories at landfall, peak intensity, etc.

The tropical cyclone seasons in the Southern Hemisphere begin in July and end in June, while the Northern Hemisphere seasons are counted from January to December. Storms are counted in all basins, months, and years in which they occur, which means some storms may appear more than once. However, the global totals only include each storm one time.

References

• Chu, J.-H., C. R. Sampson, A. S. Levine, and E. Fukada, 2002: The joint typhoon warning center tropical cyclone best-tracks, 1945–2000. Naval Research Laboratory, Reference Number NRL/MR/7540-02-16, 22 pp., https://www.metoc.navy.mil/jtwc/products/best-tracks/tc-bt-report.html.
• Knapp, K. R., M. C. Kruk, D. H. Levinson, H. J. Diamond, and C. J. Neumann, 2010: The International Best Track Archive for Climate Stewardship (IBTrACS). Bull. Amer. Meteor. Soc., 91, 363–376, https://doi.org/10.1175/2009BAMS2755.1.
• Landsea, C. W., and J. L. Franklin, 2013: Atlantic Hurricane database uncertainty and presentation of a new database format. Mon. Wea. Rev., 141, 3576–3592, https://doi.org/10.1175/MWR-D-12-00254.1.
• ——, G. A. Vecchi, L. Bengtsson, and T. R. Knutson, 2010: Impact of duration thresholds on Atlantic tropical cyclone counts. J. Climate, 23, 2508–2519, https://doi.org/10.1175/2009JCLI3034.1.
• Schreck, C. J., K. R. Knapp, and J. P. Kossin, 2014: The Impact of Best Track Discrepancies on Global Tropical Cyclone Climatologies using IBTrACS. Mon. Wea. Rev., 142, 3881–3899, https://doi.org/10.1175/MWR-D-14-00021.1.