Properties are now taking five days longer to reach an offer or exchange stage than a year ago.
Data from Rightmove shows that the average time to sell a property across Great Britain hit 77 days last month, up from 72 days in January 2018.
Time to sell is based on a property being first listed on Rightmove until it is marked as under offer or sold subject to contract by an agent.
However, there are significant regional variations.
Towns in the west and east midlands dominated the top ten quickest-to-sell locations, Rightmove said, with Redditch taking the top spot at 45 days.
Runcorn in Cheshire has seen the biggest improvement, with time to sell falling from 69 days in 2018 to 48 this year.
Camden in London took the crown for the slowest market, with homes going under offer within 121 days on average, while Middlesbrough had the longest time on the market outside of the capital at 110 days.
Miles Shipside, property expert for Rightmove, said: “This analysis reflects what agents have recently been telling us, and what we saw in Rightmove’s House Price Index – that more northerly regions are faring better in terms of pricing power and willingness to move than those further south.
“Agents report that properties in the north-west are seeing positive market conditions with strong demand from buyers.
“Once again, improvements in local-level infrastructure is a key factor, with the top areas benefiting from better transport links to bigger city centre employment hubs.”