Like a runaway locomotive, Toronto is steaming toward the second-warmest year on record — and the No. 1 position is clearly within striking distance.

Right now, 2010 is sitting at No. 2, but by only the slimmest of margins.

From January to Sept. 19, the average temperature has been a relatively toasty 11.6 C.

We trail only the 11.7 C average recorded from January-December in 1998, says David Phillips, senior climatologist at Environment Canada.

The normal temperature for January to Sept. 19 is 9 C.

“This is the second-warmest such stretch in Toronto’s history,” Phillips said.

“We’re on a roll here.”

He speculated that only an unexpected cold snap will stand in our way from breaking the record by the end of the year.

“You almost need a cold front to come through and last until Christmas to prevent this,” Phillips said.

With the first full day of autumn landing on Thursday (officially it arrives tomorrow at 11:09 p.m.), Phillips doesn’t see anything in the Environment Canada models to suggest the city won’t break the record.

However, don’t expect winter to be as tame as last year, he said.

“Last year winter wasn’t postponed. It was cancelled,” Phillips said, recalling that Toronto recorded the lowest snowfall on record dating to 1937.