October fog rises off the Merrimack and hangs beneath the Route 213 bridge until mid-morning, and Domark Landscaping LLC is out working in it — last cuts of the year, leaves hauled off lawns that slope down toward the water. Then the calendar turns and the same trucks carry plows: driveways cleared before daylight, walkways opened to the door, sand and salt down before ice sets on a north-facing grade. Methuen weather rarely announces itself, since rain becomes sleet somewhere over the river and the thermometer does the rest. The reward is simple and worth having — a driveway you can back out of without thinking about it. Come July, it is the opposite pleasure: a lawn cut so evenly it reads like fabric.