Garden Tip 155:
FREQUENT RAIN MEANS FREQUENT MOWING

Maintaining a healthy lawn calls for frequent mowing during times of frequent rains. This is especially true if you are using a mulching blade (recommended) as opposed to cutting and bagging.
If grass blades grow too tall between mowings they can actually begin to shade themselves out which can weaken and discolor the lawn. It is always recommended to mow high, but one should consider sun exposure when deciding on a cutting height.
My mower has settings from 1 to 6, with 1 being the lowest cut and 6 the highest. My front lawn is in full sun and I mow that on 6. Part of my back yard is half-day sun and gets mowed on 5. Further back I have lawn in shade which gets mowed on 4.
This practice allows me to mow at the highest setting relative to sunlight and prevents the lawn from shading itself out. For a more finished look, the outside edge of the lawn can be mowed at one setting lower than the main lawn.