Global temperatures have risen steadily for over 40 years. In that same period, Atlantic hurricane seasons have gotten busier and US tornado counts have gone up. This analysis looks at whether those trends are connected, using NASA temperature data and NOAA storm records from 1980 to 2023.

The planet is warming

Global warming has been happening for awhile now.

Every year since 1980 has been warmer than the 20th-century average. The red line shows the 10-year trend — it only goes one direction.

Every year since 1980 has been warmer than the 20th-century average. The red line shows the 10-year trend — it only goes one direction.

Since 1980, every single year has been warmer than the 20th-century average. 2023 hit +1.35°C — the hottest year on record. The last ten years are the ten hottest ever measured. Clear direction.

Storms are getting worse

As the planet warmed, Atlantic hurricane seasons got busier and more violent.

Note: When does a storm become a named storm? A storm earns a name when it reaches tropical storm strength, that means sustained winds of 39 mph or higher. Everything in the named storm count meets that threshold. Major hurricanes (Category 3 and above) have sustained winds above 111 mph.

Named storms and major hurricanes per Atlantic season. The trend line is rising. 2005 brought Katrina. 2020 broke every record with 30 named storms.

Named storms and major hurricanes per Atlantic season. The trend line is rising. 2005 brought Katrina. 2020 broke every record with 30 named storms.

In the 1980s, a busy hurricane season meant around 10 named storms. By the 2010s and 2020s, that became the floor and not the ceiling anymore. 2020 had so many storms we ran out of names and had to use the Greek alphabet!

It’s not just more storms, they’re stronger too. Major hurricanes (Category 3 and above) are becoming more common too.

Tornadoes tell a similar story.

US tornado counts per year. Total numbers are rising. 2011 stands alone — the deadliest tornado year in modern history, with 553 deaths.

US tornado counts per year. Total numbers are rising. 2011 stands alone — the deadliest tornado year in modern history, with 553 deaths.

April 2011. A single outbreak produced 758 tornadoes in one week across the South and Midwest. 553 people died. It remains the deadliest tornado stretch in US history. Events like that used to be once-in-a-generation. They’re becoming more frequent.

Here’s the connection

Put temperature and storm activity on the same chart and the relationship becomes hard to ignore.

Named storms (bars) and global temperature (blue line) tracked together from 1980 to 2023. As one rises, so does the other.

Named storms (bars) and global temperature (blue line) tracked together from 1980 to 2023. As one rises, so does the other.

The correlation between temperature and named storms is r = 0.61. That’s strong. It means warmer years reliably produce more Atlantic storms — not occasionally, not sometimes, but consistently across four decades of data.

The same pattern holds for tornadoes.

Note: To measure how closely temperature and storm activity move together, we use the Pearson correlation coefficient (r). It runs from -1 to +1. Zero means no relationship. One means a perfect one. Named storms score r = 0.61 against temperature. That is a strong positive relationship, warm years consistently produce more storms across all 44 years of data.

Each dot is one year. Warmer years sit higher on the chart — more tornadoes. Point size shows how many major hurricanes hit that same year.

Each dot is one year. Warmer years sit higher on the chart — more tornadoes. Point size shows how many major hurricanes hit that same year.

Why? The physics are straightforward. Hurricanes run on warm ocean water, the warmer the water, the more energy a storm can pull in. Tornadoes need warm, moist air colliding with cool, dry air. A warmer atmosphere holds more moisture and creates more of those unstable conditions. Climate change doesn’t create storms, but it does provide them the fuel it needs to thrive.

Every decade worse than the last

If we zoom out from individual years and the pattern is even cleaner.

Decade averages for temperature, named storms, and tornadoes. All three move in the same direction.

Decade averages for temperature, named storms, and tornadoes. All three move in the same direction.

The 1980s averaged 9 named storms per season. The 2020s are averaging 18!
Tornado counts follow the same staircase. And the temperature bars keep getting darker red.

What this means

Al Gore was right. Kidding, but this data doesn’t prove that climate change caused any specific storm. What it shows is a 44-year pattern with a consistent direction: as the planet warms, conditions that generate and intensify storms become more common.

The good news: fatalities haven’t risen with storm counts (r = 0.02). Better early warning systems and preparedness have kept that number in check even as storms get worse.

The bad news: the temperature trend isn’t slowing down. If the last four decades are a preview, the next four will be worse.