That means, according to legend, that spring is just around the corner.
CBS station KDKA-TV in Pittsburgh reports a cheer went up as members of the local Groundhog Day club made the announcement, shortly after dawn. If Phil had seen his shadow, it would have meant six more weeks of winter.
"We will feel winter's wrath, but spring is coming," said Bill Cooper, president of the Inner Circle, the club that stages the annual midwinter festival.
Officials were reporting that the largest crowd ever, an estimated 25,000 people, had gathered for the groundhog's appearance. The band played the Star Spangled Banner as festivities got under way under a cloud-filled western Pennsylvania sky.
It was the same cheery news (if you believe in such things) in Lilburn, Ga., where Georgia's groundhog forecaster, Gen. Beauregard Lee, also failed to see his shadow.
The Groundhog Day tradition is rooted in a German superstition that if an animal casts a shadow on Feb. 2 - the Christian holiday of Candlemas - bad weather is coming.
But in the 110 years since German farmers began the festival in Punxsutawney, the morning of Feb. 2 has evolved into an elaborate show of hoodwinkery.
In years past, members of the club voted the night before whether or not Phil would see his shadow, rain or shine. Despite overcast skies last year, the club announced the shadow appeared. They set off fireworks to simulate a sunrise.
This year, club members insisted, they did not decide what Phil's decision would be until they actually approached his burrow.
For the record, Phil has predicted six more weeks of winter 100 out of his 112 appearances. He's been right about 40 percent of the time.
Mike Simmons made a four-hour trip from the town of Tunkhannock to be in Punxsutawney. Asked why, he said: "I have no idea. For the absurdity?"
"It's something unusual," offered his friend, Sandra Peoples of Scranton. "Something you can say you did once."
"And only once," added Simmons' wife, Jackie.