Islamabad, Pakistan (CNN) -- Intense rains let up in parts of northwestern Pakistan on Thursday, giving humanitarian groups a chance to get more aid to the millions of people suffering.
The dry skies were a respite for areas battered by the heavy rains, which left behind bloated rivers and covered whole neighborhoods with flood waters.
But heavy rains were still pounding some parts of the country, including Punjab and Sindh provinces.
The flooding -- caused by torrential monsoon rains -- has destroyed thousand of homes, crushed many bridges and affected 3 million people, officials said.
As many as 1,500 people have died in what has been called Pakistan's worst flooding in 70 years.
"Today is going better. It is sunny and drier, but the destruction is all around us. Most of the villages have been washed away by water," said Joseph Prior Tio, who's working with Doctors Without Borders in Pakistan's Swat Valley.
Another big issue is the many left without electricity, Tio said.
"We are fighting to get safe water to many areas," Tio said "There is simply no electricity anywhere in the entire valley. All over the valley there are about 1 million people who depended on electricity to get basic services such as safe drinking water."
U.S. Secretary of State Hillary Clinton on Wednesday urged Americans to donate to relief efforts, saying that experience in post-earthquake Haiti showed that small donations can make a big difference.
Pakistani Prime Minister Yousuf Raza Gilani appealed to residents to curtail expenditures for Ramadan feasts and upcoming independence day celebrations, and instead help their suffering compatriots.