‘Normal’ weather in Jacksonville has changed

JACKSONVILLE, Fla. – It may not come as a surprise that it feels hotter to long-time residents of Jacksonville and the surrounding areas.

But is it? First, the ground rules to explain the answer.

• Defining what the weather should be is called climate.
• The ‘normals’ establish the basis for judging how daily, monthly and annual climate conditions compare to what’s expected for a specific location in today’s climate.

A new set of ”climate normals” was released Tuesday by the National Oceanic and Atmospheric Administration showing updated weather conditions averaged over a 30-year period. It is like the U.S. Census where the average is calculated every 10 years. The latest is from 1991 to 2020 and includes more than 9,000 daily weather stations

The result? NOAA confirmed it is hotter and wetter in Jacksonville based on daily weather data from the past three decades.

How has Jacksonville changed since the last update 10 years ago?

• Jacksonville is an inch wetter, averaging 53.4 inches of rain per year.
• The average yearly temperature is 0.7 F degrees warmer. Most of the change came during the winter months, where the average rose from 54.9°F to 56.1°F.
• Springtime also warmed by nearly a degree due to milder nights.

It is noteworthy to see that the hottest parts of summer didn’t change. While nighttime temps have trended warmer, daily maximum temperatures stayed fixed close to 91 degrees. The heat over summer has been tempered by more rainfall. This is due to warmer air’s ability to hold more moisture; which explains why it has rained more often.

Rainfall has increased by about an inch per year with the greatest increase during the summer and autumn months.

Climate change does not increase precipitation equally across various locations. Other factors related to geography can result in a greater range in rainfall excess or declines across the country. While humidity supplies the rainfall locally from the Atlantic and Gulf of Mexico, western areas in the United States are seeing longer droughts.

Climate change has shifted previously established weather tracks over the past three decades leading to multi-decade megadroughts that are setting in from Mexico to the U.S. southwest.

The updated set of climate averages for the United States shows climate change is not just confined to our local boundaries.

The United States has warmed 1.7 degrees since the first climate normal was calculated during 1901-1930.

Since 1901-1930, all but two of the 30-year periods have shown an increase in temperature.

While the daily ups and downs of weather will continue, the latest climate averages show the warm trend will also continue unless change is made to reduce carbon emissions.