Many experts recommend cleaning your gutters at least twice a year– once in the late spring and once in the late summer/early fall. But it varies considerably by region, by the location of your house and trees, by the types of trees, by how much wind there is.
Here are a few pointers:
1. Clean your gutters whenever you find they have been overflowing. Common sense, but it must be said. From inside the house, you may even hear them overflowing during a storm. Don't go out during the storm, but do it afterwards, soon, before you forget.
2. If you see leaves in the gutters from the ground view, or from a high window, there is a good likelihood they will (or have already) blocked downspouts. Clean them before any rain makes them wet.
3. If your house is surrounded by lots of tall trees that drop leaves on the house, you may even have to clean your gutters twice in the fall if you want to prevent water overflowing during storms.
4. In the spring there are certain trees (maple trees are a good example) that can dump pounds and pounds of seeds onto your roof and into your gutters. There is a very good chance you'll need to clean them in the spring.
5. Pine trees can shed needles all year long. You may need to inspect or clean your gutters as frequently as every 3 months. Needles even plug up gutter guard screens quite frequently.
6. Even if you have gutter guards or gutter screens, the top of the screens can plug up with pine needles or leaves and may need to be brushed off, blown, or manually cleaned occasionally to keep them clear.
You might NOT have to clean gutters very often in you:
1. Live in areas like the plains states where many homes may not be near tall trees.
2. Trees around your house are far away, or not very tall, or both.