An earthquake earlier this month in Yushu, high on the Tibetan plateau in western Qinghai province, killed more than 2,000 people and left thousands of others homeless in freezing temperatures.
Yushu's airport, only opened last year, has been an important part of the rescue mission following the quake, enabling aid workers and supplies to bypass the 800 km (500 mile) road trip from provincial capital Xining, and helping in evacuations of the injured.
But heavy snow has closed that airport, and a sandstorm sweeping across northwest China has closed Xining airport, state news agency Xinhua said.
"All the six daily flights from Xining to Yushu were delayed," it quoted a Xining airport spokesman as saying. "It is unknown when flights will resume."
The dust has penetrated the terminal, covering chairs with yellow grit and stranding hundreds of rescuers, the report added.
Large swathes of China are often hit by dust or sand storms at this time of year.
The government has spent millions of dollars on projects to rein in the spread of deserts, planting trees and trying to protect what plant cover remains in marginal areas.
But the battle is being fought against a backdrop of rising average temperatures and increasing pressure on water resources after three decades of booming growth.