Power cuts blamed on ice and unusually heavy snowfall yesterday left about 100,000 people waiting for trains in the key southern Chinese rail hub of Guangzhou, state media reported.
Air travel has also been affected, with numerous flights delayed out of Shanghai, where light snow was falling.
The bad weather comes at the worst possible time for travelers and transport authorities, as the country moves into the peak Lunar New Year travel season with tens of millions of Chinese on the move by train, plane and bus.
Most of the delays were blamed on cuts that left 136 electric passenger trains stranded on the tracks in Hunan Province, which lies at the midpoint of the main Beijing-Guangzhou railway, the official Xinhua news agency said.
The logjams, which also struck as far away as Kunming in the country's southwest, have been compounded by a slowdown in bus travel because of the closure of icebound highways.
Most of those stuck in Guangzhou were migrants working in the region's export industries who were returning to their homes elsewhere for the holiday, the main time for Chinese family gatherings. The holiday this year falls on Feb. 7.
Hunan and other parts of central China have been hit in recent days by freakishly cold weather, icy rain and snow that has accumulated on power lines, causing them to snap in places.
Some areas have seen the heaviest snowfalls in more than a decade, with more bad weather forecast for the coming days.
The railway authority had sent almost 10,000kg of rice, vegetables, meat and edible oil, along with 20,000 boxes of instant noodles and drinking water to relieve those stuck aboard trains, Xinhua said. About 100 diesel locomotives were being dispatched to move the trains along, the report said.
The harsh weather has aggravated the customary winter power cuts by blocking coal deliveries, while the government last week issued a wide-reaching order to speed up food shipments to markets in hopes of reining in persistent inflation.
Under the measure, food trucks will be exempt from paying road tolls.
Double-digit percentage increases in food prices for much of the past year have driven China's overall inflation rate to among its highest levels in a decade.
Last month, consumer prices were 6.5 percent higher than in the year earlier.