Slobodan Radoman ’07 and Karolis Balciunas ’08 talk to friends after finishing the Boston marathon in costume yesterday afternoon.

As spectators, friends, and family looked on, dozens of Harvard students braved howling winds and temperatures in the 40s, as they joined more than 20,000 other runners in the 111th annual Boston Marathon yesterday.

Yesterday’s runners began the race under some of the toughest conditions in years, but the rain eased off about an hour after the fastest runners left the start line, leaving behind a slick race course.

The Harvard students who completed the 26.2 miles from Hopkinton to downtown Boston didn’t just brave a grueling race.

They also raised thousands of dollars for charity.

Among them were 30 students and staff who were sponsored by the Harvard College Marathon Challenge (HCMC), raising more than $30,000 for Phillips Brooks House Association and Project HEALTH.

Jessica H. Chao ’07 ran the marathon for Harvard China Care, a student group that helps special-needs orphans in China. Surrounded by fellow Harvard China Care members near the finish line, Chao said she actually enjoyed running in the rain, adding, “it was comfortable.”

But, she was quick to note, “my shoes got soaking, filthy wet, at the start.”

Many runners, including Chao, had to cross a muddy field to reach the Hopkinton start line.

Weather forecasts aroused such concern among the race’s organizers that they sent an e-mail to all participants a few days before race day. The message urged runners to take special precautions for the predicted cold and wet conditions, as hypothermia risk would be particularly high.

When Sarah MacCarthy, a graduate student at the Harvard School of Public Health, received the e-mail, “it scared everything out of me,” she said.

MacCarthy ran yesterday’s race to honor her uncle, who was diagnosed with brain cancer two years ago.

“Seeing him struggle with the disabilities of cancer [and] get through all the surgeries—it’s been hard, it’s been sad, and it’s been inspiring,” she said.

Through her marathon run, MacCarthy raised more than $4,000 for the Brain Tumor Society.

HCMC runners met for a 7 a.m. breakfast at Lowell Dining Hall yesterday morning.

Speaking at the pre-race breakfast, HCMC member Emily P. Balskus, a chemistry graduate student, recounted how she had sustained a stress fracture in her left ankle a week and a half before last year’s Boston Marathon. The injury left her unable to run the race.

“I had done everything, including a 21-mile run,” she said.

This year, Balskus stayed injury-free.

Receiving a massage in the Quincy House Junior Common Room a few hours after finishing the marathon, Balskus said she was “very happy” with her performance.

Race conditions gradually improved as the day wore on, and by the end of the course most runners had removed their heavy top layers and tied them around their waists.

But the marathon was not all wind, rain, and sweat. Halfway through the race, participants reached the “Wellesley Scream Tunnel”—the stretch of the course that runs past the all-women’s Wellesley College. Every year, Wellesley students line up along this section of the course to scream and cheer while holding up signs.

Five years ago, one marathoner told The Crimson that the scream tunnel was “the best half-mile in all of running.”

Charlton “Chad” Volpe ’07, who also ran under HCMC, added yesterday, “You could hear [the screams] from a mile out. Coming up, it’s the loudest thing ever.”

The final few miles of the course, located in downtown Boston, took on a festive air as stands displaying wares lined the street and crowds cheered on the runners. Some children climbed up trees that lined the streets to gain a better view.

Kenyan Robert K. Cheruiyot won the men’s title at the Boston Marathon yesterday for the second straight year, coming in with a time of 2:14:13—a little less than seven minutes slower than the course record he set last year.

Overall, Kenyans dominated the men’s race, making up seven of the top 10 places.

On the women’s side, Russian Lidiya Grigoryeva took the title with a time of 2:29:18, which was more than eight minutes slower than the course record set five years ago.

—Staff writer Khalid Abdalla can be reached at kabdalla@fas.harvard.edu.