Tips on How to Cut Grass after Rain. Rain to grass is what gasoline is to fire. With just a few good days of rain, the grass would have grown enough to require mowing. Especially in the spring months. However, it is not advisable to cut grass when wet. Wet grass tends to bend over due to the weight of water on their blades making it difficult to achieve a straight cut during mowing. Another problem is that the wet grass may clump on your lawn and inside your mower cavity. The clumps may kill the grass underneath them if they are not properly raked. However, it is may also be a bad idea to wait until the grass dries to give your lawn a cut. So, what can you do if your grass is overgrowing yet it’s a rainy season?