Last updated by The POOG on January 12, 2021.

Weather is what is happening with the atmosphere and adjacent biosphere now, in a particular place. Climate is the long-term average of weather data. A 13-year simple moving average – the average of 13 years of weather data – is often used to create a single climate data point.

Weather data is ‘noisy’. It can vary considerably from day to day and location to location. Such variability hides the long-term trends that climate is trying to measure.

We have short memories, sometimes intentionally, so measuring and recording weather data over time is important to give us perspective. This article will give a historical view of weather events by category.

Severe ocean storms have a variety of names for the same weather event as explained by NASA[1]: “Hurricane”, “Typhoon”, and “Cyclone” are all different words for the same phenomena. A major source of data is The National Hurricane Center and the Central Pacific Hurricane Center of the US National Oceanic and Atmospheric Administration (NOAA).

Atlantic Hurricanes

NOAA provides archived data on Atlantic, Eastern Pacific, and Central Pacific hurricane at the NHC Data Archive and Tropical Cyclone Reports.

The Atlantic hurricane season runs from June 1st through November 30th. To get a list of storms by name by year, go to Tropical Cyclone Advisories. The Atlantic hurricanes from 1944 to 2015 are represented in Figure 1.

Figure 1. Number of Atlantic hurricanes, 1944 to 2015. Red: major hurricanes (category 3 and higher); blue: others. Source: University of Arizona.

A longer term chart of all Atlantic storm systems is shown in Figure 2.

Figure 2. Number of storm systems by year. Source: MarketWatch.

The modern era of satellite tracking beginning in 1979 has allowed for an accurate count of storm systems globally. Before that, information was collected from ships and aircraft encountering them as well as landfall accounts. Before the era of aircraft and global trade, storms might occur and never be witnessed. Some Atlantic storms never make landfall. The further back in time into the 19th century and earlier, the more likely that storms might be missed. One has to assume, therefore, that data in Figure 2 is incomplete, making comparison with recent data approximate.

Tornadoes

Detailed tornado data for the United States is available from NOAA’s National Weather Service, National Centers for Environmental Prediction, Storm Prediction Center. The page, Latest U.S. Tornado Statistics, has monthly severe weather summaries from 2000 to date. If you click on a year, it opens a page showing detailed tornado, hail, and wind events by month and by state. We have extracted annual totals in Table 1, below.

YearTornadoesHail
2021  
202012434611
201916765396
201811694611
201715226045
201610595601
201512595412
201410575537
29139435458
201211197033
201118949417
201015435913
2009130510223
2008168517680
2007110212637
2006111716566
2005126213640
2004182013088
2003137413857
200293812485
2001121912143
2000107211223
Mean1303.719456.00
Table 1. Source: NOAA’s National Weather Service National Centers for Environmental Prediction Storm Prediction Center

As may be seen from the data, 2020 was about 5% below the annual mean for the last 21 years of tornadic activity.

References

  1. What is a Hurricane, Typhoon, or Tropical Cyclone? NASA. As of January 10, 2021.