Web alarm clock for 5:02 a.m.
While you wait to escort the children across a flooded street, set the alarm for 5:02 am and keep an eye on the time. The early start leaves room to check how high the water is, choose a passable route, and gather umbrellas before everyone steps outside. With 6:00 am still ahead, the alarm marks the exact moment to begin rather than leaving you to watch the clock continuously.
Because this alarm runs in your browser, closing its page or the browser can silence the alert. That could leave the children waiting when it is time to cross the flooded street, so keep the page open until 5:02 am. Also prevent the phone from going to sleep, leave the sound audible, and avoid switching to a setting that mutes browser audio. A quick glance at the displayed alarm time can confirm that the intended early-morning moment is still set.
Before heading toward the flooded street in the dim pre-dawn light, lower the screen brightness enough that checking 5:02 am does not feel glaring. Use a warm display setting if your phone provides one, then place it where the time remains readable without holding the bright screen close to your eyes. Once the alarm sounds, lock the screen and let your eyes adjust to the outdoor lighting before guiding the children along the route.