Kendra Stokes sat in the grass, kicked off her flip-flops and squinted at her laptop. The sky over the Memorial Union Quad was brilliant blue, and the sun reflected off her computer screen, making it hard to read.

Ah, the perils of studying during the summer.

Stokes just moved into a house with friends, and because she's paying rent here, the senior public health major figured she'd get ahead by taking a few classes during her first summer in Corvallis.

"It's relaxed," said Stokes of the summertime pace. "It's a lot more peaceful."

Oregon State University's enrollment is nearly 20,000 students during the school year, but that number dips sharply during the warm months. Summer enrollment, however, climbed to 6,866 last year, up 45 percent from 1999. That compares to a 23 percent increase for the regular school year during the same period. The number of students in campus classes also has risen this summer by about 2.5 percent, said Martin Barry, OSU's summer session director. He attributed the surge in warm-weather students to the university offering more courses, including online classes.

About a third of OSU's summer term enrollment last year came from students attending classes on their computers, and online courses have seen an 18 percent jump in enrollment compared to summer 2007.

"Students can keep going to school during the summer, but they can go back home," said Lisa Templeton, OSU Extended Campus director of marketing and communications.

Another trend for the summertime is that 25 percent of the enrolled students are from out-of-state instead of the 20 percent customary during the rest of the year. That's probably because no out-of-state tuition is charged during summer term.

"During summer, there's nothing else to do here, so you might as well take summer school," said Chantel Peterson, a sophomore interior design major from Hawaii.

"I like it during the summer," said Iamafana Tuimalealiifano, a sophomore from Hawaii who plays defensive line for the OSU Beavers football team. "It's not as packed. You don't have to wait for things."

"I kind of prefer it like this, rather than the hustle and bustle," said Justin Smith, an MBA student from Tahoe City, Calif.

Summer term includes one-week, four-week, eight-week and 11-week classes. The last session begins Aug. 18, and students can enroll up to that day.

OSU students aren't the only people enjoying the sunshine on campus. The university hosts youth camps and programs, including OSU KidSpirit, a day camp that has about 200 kids on campus on any given weekday.