The city aired on the side of caution at the Macy’s Thanksgiving Day Parade yesterday after two parade onlookers were injured last year when an M&M balloon wrapped around a light post.

Heavy winds and downpours caused the city and Macy’s to fly the trademark Thanksgiving Day balloons at a precautionary low height that could handle wind speeds of 17 mph, a spokesman for the New York City Office of Emergency Management, Jarrod Bernstein, said.

“It looks like Sponge Bob’s face is dragging on the ground,” a reveler from the Upper West Side, Erin Fitszimmons, said. “I’m going home.” A spokeswoman for Macy’s said she did not know the exact heights of the balloons.

To determine safe balloon altitudes, the city placed anemometers, devices that measure wind speeds, at each major intersection along the parade route. The anemometers fed to a central hub where the Office of Emergency Management, the police, and Macy’s officials could observe the wind speeds, a spokeswoman for Macy’s, Leina Kazin, said.

Although Macy’s had used anemometers in the past, this was the first parade where officials could monitor winds speeds on the ground and the elevations of the balloons, Ms. Kazin said.

The new procedure was part of recommendations issued in September by the mayor’s Thanksgiving Day Parade Task Force following the M&M incident.

By 1 p.m. yesterday, about half of an inch of rain had fallen, winds speeds had reached up to 16 mph, and temperatures dipped into the low 40s, according to the National Weather Service.

Parade-goers, holding tightly on to umbrellas and dawning rain-gear, packed the sidewalks along Central Park West to take part in the festivities. Steven Plofker, a 15-year parade veteran, sat with his family of seven watching the procession at 72nd Street from makeshift bleachers constructed from two ladders and wooden platform. “This is the worst weather I’ve ever seen at the parade,” he said. “But we are staying until the end.”

According to Mr. Bernstein no major injuries were reported at the parade.