Sydney is on track to experience its second hottest spring on record, with November expected to crack the top four hottest Novembers since record-keeping began, according to the Bureau of Meteorology.

For the past three consecutive years, Sydneysiders have sweated through the warmest spring periods to date.

"[This year] it wasn't quite as warm as spring 2013, which is the warmest on record, but slightly warmer than spring 2014," said climatologist Acacia Pepler from the Bureau of Meteorology.

With one day left on the calendar, the mean overall temperature in Sydney for this November is currently tracking slightly behind 2009's record of 22.4 degrees when the average daytime temp was 26.1 degrees.

"2009 was also the warmest November on record for NSW. It was a pretty exceptional November that year," Ms Pepler said.

"For the 150 years or so the [bureau's] station in Sydney has been open, the all time average for November is about 19.7 degrees, which gives you a sense of how much above average 2009 was."

This month is currently jostling for second position on the record charts with November 1914 when the overall temperature was 22 degrees and the average day time temperature was 25.4 degrees.

"With still a day to go it could easily go either way," Ms Pepler said, with 2014 rounding out the top four and 1894 claiming the fifth warmest November.

"In the top 10 [Novembers] we've got a lot of recent years, including 2011 and 1997. There are also a couple of those really warm Novembers back at the end of the 19th century."

On November 20, Sydneysiders endured the second hottest November day with mercury peaking at 40.9 degrees. November 25, 1982 still holds the November record with 41.8 degrees.

Both climate and weather factors are responsible for the trend of warm weather across the spring period in recent years.

"The first reason is that Australia and the globe have warmed by about a degree over the last century. What that means is that we're more likely to break high temperature records and less likely to break cool temperature records than we would be if the climate was stationary."

Secondly, Australia is experiencing an el Nino year, which typically brings "hotter and dryer weather to eastern and south eastern Australia."

Specific weather events have also played a role, with strong north-westerly winds responsible for the stifling heat on November 20 and 26.

"The winds basically draw all the really hot air from Alice Springs right down onto the coast."