First watering in a week

According to the moisture meter, the moisture level of the soil in the pots has been slowly dropping, yet some areas still (oddly enough) register as Wet. I'm finding that hard to believe so I've decided to drop the highest and lowest moisture readings when trying to determine how moist the soil is. Since the temperature is supposed to reach into the low 90's today and neither plant has been given any water for about a week, I turned on the drip irrigation for 15mins for both plants this morning.