You know it’s hot now. But it used to be hotter.

In Vicksburg, records show, the average temperature from 1975 to 2004, 64.7 degrees, is about half a degree cooler than it was between 1894 and 1924, said Bill Frederick, the National Weather Service’s liaison to the U.S. Army Corps of Engineers’ Mississippi Valley Division.

Why is it lower? It may be, he said, because of another long-term weather trend, an increase in rainfall and the clouds that come with it.

The average rainfall over southwestern Mississippi for the most recently ended 30-year period is about 8.7 inches greater than that for the corresponding period that ended 80 years earlier, he said.

“I think it’s just changing, getting more moisture from the tropics up into the area,” Frederick said. “That’s just my gut feeling.”

He wouldn’t give an opinion on global warming, the theory that more greenhouse gases in the atmosphere due to industrialization are damaging the Earth’s ozone layer and causing temperatures to rise worldwide.

Frederick has worked at the Mississippi Valley Division, 1400 Walnut St., since 2001. He formerly worked with the National Oceanic and Atmospheric Administration’s National Hurricane Center in Miami, Fla. Today his job is to provide weather insight to the division’s command staff.

“They make a lot of decisions based on it,” Frederick said of the information he interprets and provides.

Despite all the educated weather forecasting, record-keeping and documenting, temperatures are about how hot or cool one is.

For example, a few residents of local nursing homes who have seen many seasons change have opinions on what may have brought the changes.

Hattie Truly, 94, of Covenant Health & Rehab of Vicksburg, 2850 Porters Chapel Road, said it seems cooler to her now and admitted it’s probably because she’s retired from the kitchen of a Vicksburg hospital, where she worked for 37 years.

“It seems cooler,” Truly said. “I was cooking.”

Truly said she grew up near Ballground Plantation northeast of Vicksburg. The spot where she and her family liked to cool off was in the shade of a tree, and they used pasteboard for a fan, she said.

Elizabeth Blum, 97, of Heritage House Nursing and Rehabilitation Center, 3101 Wisconsin Ave., said she grew up on a farm off Fisher Ferry Road.

“We’re having some hot days but they’re not as difficult as the ones back then,” Blum said. “We didn’t have electricity. We had to fan ourselves. I guess that’s the reason that I don’t think it’s hotter.”

The Rev. L.B. Currie, 105, of Vicksburg Convalescent Home, 1708 Cherry St., said the weather these days feels “not hotter” and “about the same” as it did when he was growing up in Vicksburg.

Currie said his favorite way to cool off was to go swimming and that he would swim “anywhere” he could.

Frank Pittman, 77, also of Vicksburg Convalescent, said he left Vicksburg to enter the U.S. Army at age 21 and returned about seven years ago.

“This year seems a little warmer, because when I was growing up I saw some real cold days here,” Pittman said. “Right now it’s warmer. It’s getting so you can’t tell the summer from the winter.”

Looking at temperature trends season-by-season, Frederick said records show Vicksburg winters getting slightly cooler, springs staying about the same, summers getting a little cooler (“even though you couldn’t tell”) and falls getting a little cooler as well.

“The biggest change is in the summers,” Frederick said. “The biggest increase in rainfall is in the fall.”

Vicksburg’s average summer temperature is about 80 degrees, and its average winter temperature is about 50, Frederick said. Ranges for the St. Louis area and a location in Minnesota, for instance, show comparable ranges of 45 and 57 degrees betweem their summer and winter temperatures, he said.

“The further south you get the narrower the seasonal temperature range,” he said.

The times with the highest concentrations of rainfall throughout the year here are also shifting, Frederick said.

“We used to get it starting in the middle of April and on and now it’s shifting more towards the middle of May,” Frederick said. “So we are getting more rainfall later.”