The data below is showing seasonality; based on over 15 years of data from the Real Estate Institute.
As you can see, March is the most active month of the year, with January being the least active.
The majority of new property listings tend to flood onto the market in February & March and again in October & November. In fact, 40% of all new listings in a year, come onto the market in these 4 months. The winter season (between the months of June, July and August), has the lowest level at 20% of the annual total of all new listings hitting the market.
It is a common tendency among sellers to list either in the spring or summer, as it is warmer and the gardens and property overall is looking in it's best shape, you have more competition as everyone has the same idea!
However, some sellers decide to list in the winter season as they feel it could give their property greater exposure at a time when fewer listings are out in the market to compete with.
At the end of the day, buyers will buy a home that they feel suits their needs - rain, hail or shine so whatever the season, if your home is well presented, well promoted and well priced you are sure to achieve a sale.