The number of hot spots soared in the past year, hitting 100,355 last week, up from about 57,000 a year ago, the South San Francisco-based company is expected to announce Tuesday.

The U.S. leads the world in hot spots, with 37,073, JiWire said, followed by the U.K. with 12,668. The other eight countries in the top 10 are South Korea, with 9,415 hot spots; Germany, with 8,614; Japan, with 5,951; France, with 3,886; Italy, with 1,767; the Netherlands, with 1,703; Canada, with 1,397; and Switzerland, with 1,295).

The city with the largest number of hot spots is Seoul, with 2,056, followed by Tokyo (1,802); London (1,627); Paris (895); San Francisco (801); Daegu, South Korea (787); New York (643); Singapore (619); Busan, South Korea (617); and Hong Kong (605).

JiWire said 8,118 of the hot spots were free, and 92,237 charged fees for access. David Blumenfeld, vice president of marketing at JiWire, said daily fees for Wi-Fi can run from a few dollars to US$15 for a hotel, while a monthly fee might run up to $40.

Free hot spots are on the rise, but there will always be hotels charging premium rates, and many airports will continue to charge users, since they can't easily walk to a free network, he said.