The estimated 3.5 million people who will flock onto the streets of Manhattan for the annual Macy’s Thanksgiving Day Parade should be prepared to wrap up and have an umbrella at the ready. Cold temperatures and light rain showers are expected in New York City during the pageant, which will begin at 9 a.m. EST on Thursday.

"A weak storm system will pass by New York City on Thursday and bring a little rain to the city," AccuWeather Meteorologist Jordan Root said. "Temperatures will be in the middle 40s."

The forecast is a departure from the unseasonably mild fall temperatures New York City had been enjoying in recent weeks. However, the weather is an improvement from earlier in the week, which saw frigid temperatures, high winds and even some fleeting snow around.

Those traveling in and out of the city during the holiday should also be on alert for fog in the area. The parade is scheduled to go ahead rain or shine, although sustained winds in excess of 23 mph and gusts in excess of 34 mph can lead to the larger balloons being kept out of the parade, which runs down a 5.5 mile route from 77th street down to 34th street and the flagship Macy’s store in Manhattan.

That almost happened in 2013. Only a late decision by the New York Police Department on the morning of the parade that year allowed it to go ahead at full steam, even if Sonic the Hedgehog did get caught in a tree.

There was a far more serious weather-related incident in 1997, when strong winds caused a Cat in the Hat balloon to strike and break off a light pole, leaving one spectator in a coma for 24 days. After another wind-related incident in 2005, Macy’s said it had updated its monitoring system of weather patterns.

Only once in the parade’s history have the balloons been grounded, due to a torrential downpour in 1971.

This year’s parade will feature 16 giant balloons, 30 floats, 1,000 clowns, 8,000 participants and more than 1,100 cheerleaders and dancers.