Anyone flying Air Canada and WestJet recently has likely noticed that empty seats are rare. New figures show just how rare they are.

WestJet said Thursday it filled a record 88 per cent of its seats in August, while Air Canada's jets flew with 83.8 per cent of their seats occupied with paying passengers — the second-highest load factor the carrier has ever reported.

WestJet said its available seats rose by 15 per cent, while passenger traffic — as measured by revenue passenger miles — jumped 20 per cent compared with August 2006.

"We anticipate this positive trend to continue as we take delivery of two more aircraft before the end of the year, bringing our fleet size to 70," said WestJet CEO Sean Durfy.

WestJet shares jumped 75 cents to $16.65 in TSX trading as investors welcomed the news.

At Air Canada, overall system traffic at the mainline carrier and at its regional carrier, Jazz, rose by 4.1 per cent in August, while capacity grew by 3.9 per cent.

"The solid results were driven largely by our performance in the domestic market, where our traffic grew 7.2 per cent over last year and we benefited from the positive trends seen in the Canadian industry as a whole," Air Canada CEO Montie Brewer said.

Air Canada's Class A shares were unchanged at $11.54. Its traffic figures were released late Thursday after the stock market closed.

Air Canada made $155 million in its most recent quarter, while WestJet reported net earnings of $11.5 million.