Longest day and shortest night of the year occur on this date, marking the beginning of summer. A.K.A. Midsummer.
At the point of the summer solstice in the Northern Hemisphere the sun appears to be directly overhead at midday along an imaginary line on the Northern Hemisphere at latitude 23.45 deg N known as the Tropic of Cancer.
Depending on where you are in the Houston area, you may or may not even notice the extended daylight. Usually, this would not be such a bad thing considering Houston is in one of its hottest months. A little cloud coverage usually helps on this day to relieve us of the extra heat...although considering the continuous rain, the sun might be welcomed to dry out some of the flooding.
Happy Summer Solstice.