When planning a day hike with kids, always first check a weather report for where you plan to walk.
Knowing the weather also can result in a lighter load. There’s very little need to bring wet weather gear if there’s no rain forecast for a 100 miles around and you’re going to be out for just a couple of hours. If on a hike of more than a couple of hours, though, be aware that weather fronts can move quickly, turning a lovely sunny morning into a bitterly cold, gray afternoon.
Weather forecasting is a difficult craft at best. A prediction about temperatures and rainfall usually is only good for about 48 hours. Though you may have planned the weekend hike Wednesday evening, canceling the hike on a gray Saturday morning always is better than spending a few extra days in the wilds hoping a rescue team finds you because you were cut off high waters.
Read more about day hiking with children in my guidebook Hikes with Tykes.