Average prices are 5.5% higher than a year ago, the highest annual growth rate for over four years.
The average price of property coming to market increased by 1.1% (£3,534) in September, to an all-time national record of £323,530, according to the Rightmove House Price Index.
This is 5.5% (£16,818) higher than a year ago, and shows the highest annual growth rate for over four years.
As a result of this trend, Rightmove has forecast that the annual rate of increase will rise further before the end of the year, peaking at around 7%; this is compared to Rightmove's original forecast of 2% in December last year.
Despite market closure between late March and mid-May, 2% more sales have been agreed so far this year than in the same period in 2019.
September saw three new records for market activity: average time to sell hit 50 days, 12 days faster than the same period last year; for the first time, estate agents had more properties marked as sold than as available for sale;and the number of sales reported was 70% higher than the same period a year ago.
Rightmove also recorded a 49% increase in traffic in September, compared to the same period last year, which is the biggest year-on-year jump since 2006.
So far in October, the number of sales agreed is still 58% up on the same period last year.
The number of active buyers contacting estate agents has reached a high level, up by 66% in September compared to 12 months ago, and only marginally down on the peak of +67% seen in July.
Tim Bannister, director of property data at Rightmove, said: “Previous records are tumbling in this extraordinary market, and there are still some legs left in the upwards march of property prices.
"We predict that the annual rate of growth will peak by December at around 7% higher than a year ago.
"Many buyers seem willing to pay record prices for properties that fit their changed post-lockdown needs, though agents are commenting that some owners’ price expectations are now getting too optimistic, and not all properties fit the must-have template that buyers are now seeking.
"Not only is the time left to sell and legally complete before the 31 March stamp duty deadline being eaten away by the calendar, but more time is also needed because the sheer volume of sales is making it take longer for sales that have been agreed to complete the process.
"Sellers and their agents should therefore be wary of being too optimistic on their initial asking price, as whilst activity levels continue to amaze there are some signs of momentum easing off from these unprecedented levels.”
Bannister added: “Prospective buyers are seeing properties selling fast and prices rising as they search for their next home, adding to momentum and spurring them on to act quickly.
"With the number of buyers contacting agents still up by two-thirds on a year ago, there is plenty of fuel left in the tank to drive further activity in the run-up to Christmas and into next year.
"There have also been government promises of additional low-deposit mortgage support for first-time buyers, which could prove to be timely as we run up to 31 March.
"It appears that the current momentum, assisted by the prospect of stamp duty savings, is helping to keep the housing market healthy.
"Estate agents have worked hard to give confidence to sellers and buyers alike that property viewings can be conducted safely, and early signs show that market activity still remains high in areas with stricter local lockdowns.”