Editor's Note: This story originally appeared on Porch.
In May 2021, the National Oceanic and Atmospheric Administration (NOAA) released their 10-year U.S. Climate Normals report, which provides data on typical climate conditions for locations all over the U.S. The conclusions of the data are clear: In recent years, much of the United States has grown both warmer and wetter on average.
These findings are unsurprising at this point, based on what we know about the long-running trend of climate change. Increased emissions of greenhouse gases like carbon dioxide through the use of fossil fuels have caused the Earth’s atmosphere to retain more heat, and warmer air is often wetter air: For each degree of warming, the air’s capacity to hold water vapor increases by about 7%.
Together, warmer and wetter air produces more extreme weather events. 2019 was the wettest year in the U.S. since 1973 and saw 14 weather and climate disasters that had losses exceeding $1 billion each. In 2020, that number grew to 22 — a new record, topping the previous record of 16 set in 2011 and tied in 2017.
For wet weather, these disasters often take the form of tropical cyclones, severe storms, and flooding. The past decade or so has seen a dramatic increase in the number and severity of these events. Between 1980 and 2008, the number of billion-dollar wet weather disasters exceeded five in only two years, 1992 and 1998. Since 2008, every year has had more than five disasters. And the costs have increased accordingly, with the five-year average reaching a peak of $106 billion in 2020.
Over the last century, U.S. has gotten warmer and wetter
Historical data shows how rapidly this trend has emerged. Temperature and precipitation data dating back 120 years reveals that much of the increase on both measures has taken place just in the last three decades. Temperatures in the contiguous U.S. are more than 1 degree higher on average since 1995 compared with the 1901–2000 average. Precipitation levels show much more variance year-to-year, but have gradually trended upward compared with the historical record in recent years.
Some regions experience the effects of these trends disproportionately based on geographic and environmental factors. Much of the Western U.S. is desert, where warming trends have made the region more arid, whereas the Southeast is warm and humid and has gotten wetter over time.
The regional differences are especially stark around this time of year as spring transitions into summer. During the three-month period from May to July (historically, the nation’s rainiest three-month period), regular summer rains drench many states in the South, led by Florida, which experiences more than 6 inches of precipitation per month on average. In contrast, Western states like California, Nevada, and Arizona see less than an inch per month over the same period.
These trends are similar at the local level, with most of the cities that get the most summer rain being found in the South and Midwest. To find the locations that get the most rain from May to July, researchers at Porch analyzed the recently updated 1991–2020 Climate Normals dataset from NOAA’s National Centers for Environmental Information. For each location, Porch calculated the historical average monthly precipitation, the 2020 average monthly precipitation, and the historical average maximum temperature, all between May and July.
Only cities with available data from NOAA were included. Additionally, cities were grouped into the following population size cohorts to improve relevance: small (0–99,999), midsize (100,000–349,999), and large (350,000+). The following are the large cities that get the most summer rain.
15. Columbus, OH
- Historical average monthly precipitation in inches (May–July): 4.33
- 2020 monthly precipitation in inches (May–July): 4.10
- 2020 difference from average in inches: -0.23
- Historical average max temperature (May–July): 80.6 degrees F
14. New York City, NY
- Historical average monthly precipitation in inches (May–July): 4.37
- 2020 monthly precipitation in inches (May–July): 3.33
- 2020 difference from average in inches: -1.04
- Historical average max temperature (May–July): 78.7 degrees F
13. Oklahoma City, OK
- Historical average monthly precipitation in inches (May–July): 4.46
- 2020 monthly precipitation in inches (May–July): 4.68
- 2020 difference from average in inches: +0.22
- Historical average max temperature (May–July): 86.5 degrees F
12. Louisville, KY
- Historical average monthly precipitation in inches (May–July): 4.50
- 2020 monthly precipitation in inches (May–July): 5.83
- 2020 difference from average in inches: +1.33
- Historical average max temperature (May–July): 84.2 degrees F
11. Nashville, TN
- Historical average monthly precipitation in inches (May–July): 4.51
- 2020 monthly precipitation in inches (May–July): 3.49
- 2020 difference from average in inches: -1.02
- Historical average max temperature (May–July): 86.3 degrees F
10. Memphis, TN
- Historical average monthly precipitation in inches (May–July): 4.69
- 2020 monthly precipitation in inches (May–July): 2.36
- 2020 difference from average in inches: -2.33
- Historical average max temperature (May–July): 87.7 degrees F
9. Wichita, KS
- Historical average monthly precipitation in inches (May–July): 4.69
- 2020 monthly precipitation in inches (May–July): 3.58
- 2020 difference from average in inches: -1.11
- Historical average max temperature (May–July): 86.0 degrees F
8. Tulsa, OK
- Historical average monthly precipitation in inches (May–July): 4.71
- 2020 monthly precipitation in inches (May–July): 3.85
- 2020 difference from average in inches: -0.86
- Historical average max temperature (May–July): 87.2 degrees F
7. Indianapolis, IN
- Historical average monthly precipitation in inches (May–July): 4.71
- 2020 monthly precipitation in inches (May–July): 5.50
- 2020 difference from average in inches: +0.79
- Historical average max temperature (May–July): 80.2 degrees F
6. Kansas City, MO
- Historical average monthly precipitation in inches (May–July): 5.05
- 2020 monthly precipitation in inches (May–July): 5.21
- 2020 difference from average in inches: +0.16
- Historical average max temperature (May–July): 82.5 degrees F
5. Houston, TX
- Historical average monthly precipitation in inches (May–July): 5.37
- 2020 monthly precipitation in inches (May–July): 6.66
- 2020 difference from average in inches: +1.29
- Historical average max temperature (May–July): 89.9 degrees F
4. Tampa, FL
- Historical average monthly precipitation in inches (May–July): 5.91
- 2020 monthly precipitation in inches (May–July): 3.83
- 2020 difference from average in inches: -2.08
- Historical average max temperature (May–July): 89.9 degrees F
3. Jacksonville, FL
- Historical average monthly precipitation in inches (May–July): 5.93
- 2020 monthly precipitation in inches (May–July): 5.72
- 2020 difference from average in inches: -0.21
- Historical average max temperature (May–July): 89.2 degrees F
2. New Orleans, LA
- Historical average monthly precipitation in inches (May–July): 6.68
- 2020 monthly precipitation in inches (May–July): 11.25
- 2020 difference from average in inches: +4.57
- Historical average max temperature (May–July): 88.9 degrees F
1. Miami, FL
- Historical average monthly precipitation in inches (May–July): 8.06
- 2020 monthly precipitation in inches (May–July): 12.09
- 2020 difference from average in inches: +4.03
- Historical average max temperature (May–July): 88.9 degrees F
Methodology & detailed findings
To find the locations that get the most summer rain, researchers analyzed the latest 1991–2020 Climate Normals dataset from NOAA’s National Centers for Environmental Information. Locations were ordered based on the average monthly precipitation between May and July (historically the nation’s rainiest three-month period). In the event of a tie, the location with greater precipitation in 2020 was ranked higher. Only cities and states with available data from NOAA were included.
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