Weather is particularly hard on your concrete, especially rain, snow and freezing temperatures. All forms of precipitation will, over time, cause the very top surface of the concrete to chip and flake. Unfortunately, this will lead to the formation of tiny cracks. As water settles in those cracks, freezing and thawing during the winter months, larger cracks will form. This sets the stage for plant growth in the spring and the damage worsens. Eventually, the cracks will compromise the integrity of the concrete, and can pose a hazard on walking surfaces if the concrete heaves or buckles.
You can prolong the life of your concrete by cleaning it and sealing it on a regular basis. However, this involves more that grabbing the closest pressure washer and blasting away. You can actually damage your concrete in the process of washing it if you use pressure that is too high or if you hold the pressure washing wand too close to the concrete.