[anatnom]

Confusingly, the paper[0] cited by this article seems undecided on this front. Figure 1A of the paper puts Hurricane Patricia (2015) into hypothetical category 7, but the "current and proposed categories" in Table 1 stops at declaring category 6 wind speed > 86 m/s (or 192mph, 167 knots, 309 km/h), and category 7 doesn't make an appearance elsewhere in the paper.

I was really hoping to find an authoritative listing of the strongest storms, but it is missing in both the linked article and the underlying paper. The paper itself uses data from International Best Track Archive for Climate Stewardship, which has a confusing website. As a non-expert, the website's top windspeed[1] category lists the following storms with maximum wind speeds of >167 knots (category 6 in the proposed scheme):

    213kt - 1958 IDA
    194kt - 1958 GRACE, 1959 JOAN, 1959 DINAH, 1961 NANCY, 1964 SALLY
    185kt - 2015 PATRICIA
    184kt - 1961 VIOLET
    180kt - 1955 RUTH
    178kt - 1955 JANET,
    174kt - 1951 MARGE, 1953 NINA, 1956 WANDA, 1957 VIRGINIA, 1957 HESTER, 1957 KIT, 1957 LOLA, 1959 VERA, 1959 CHARLOTTE, 1966 KIT
    170kt - 1964 OPAL, 2013 HAIYAN, 2016 MERANTI, 2020 GONI, 2021 SURIGAE

I don't see any explanation for why there were so many fantastically powerful storms in the 1950s-60s. Perhaps the older data is of dubious quality?

[0] https://www.pnas.org/doi/full/10.1073/pnas.2308901121#t01

[1] https://ncics.org/ibtracs/index.php?name=browse-wind#210

[dwd]

There is some research regarding an increase in Saharan dust storms that retards hurricane development in the Eastern Atlantic. Apparently this is still trending upwards and has resulted in fewer hurricanes forming over the last few decades.

[scythe]

Wikipedia gives Typhoon Ida (not to be confused with various hurricanes named Ida) a wind speed of "only" 175 knots (325 kph; 202 mph) which accounts for the largest outlier in the list.

https://en.wikipedia.org/wiki/Typhoon_Ida_(1958)

[anatnom]

Confusingly, that wikipedia page cites the same IBTrACS system that I referred to, and in that page[0] the max intensity is listed at 213 knots. The data shows that the 213 knot speed was seen for measurements across twelve hours on 1958-09-24.

[0] https://ncics.org/ibtracs/index.php?name=v04r00-1958263N1314...