Hi Arline, let me help you out a little.
The right time is when the right buyer comes around to your property and likes it. But nobody has that crystal bowl. So we have to consider other points....
When do you want to close on your home, i.e. when do you want to move and find your next home?
Then a local Realtor will be able to encourage you based on the market time of properties in your style and size and price range in your area.....
You are probably right that when the weather is better more people will roam and look around and go househunting, because it is more fun, but serious buyers or those who need to buy for one reason or another, will be looking no matter what season with their Realtors' help.
But I would agree with you, if the outside of your home, i.e. the yard the landscaping the flowers, trees etc. show so much better in better weather in Spring and summer, if you have a beautiful deck and great entrance landscaping etc. then you may be able to enhance the attractiveness of your home to potential buyers when presenting it during better seasons.... But a local Realtor would be able to discuss this in detail with you, when knowing all the circumstances.
If you would like me to recommend a local trusted Realtor Colleague of mine, let me know and I gladly do so.
email@example.com just e-mail me directly and I will forward the contact info, let me know the town you are in and where you would be looking for your new home.