Summer brings heat, there is no argument there. Even at the northern latitudes, even at elevation, heat is part and parcel of summer. Many times this heat will bring humidity as well as vigorous storms. During those storms, rain falls (instead of snow) and that rain refills both surface water and deep aquifers. This is a normal process to renew the natural world.
That natural renewal can produce scenes of striking beauty. Sometimes after a storm we can witness the most spectacular sunsets or even a beautiful ephemeral rainbow. We can explain these visual effects through scientific processes, but the concept of beauty goes beyond explanation. It touches us deeply. Knowing how or why an atmospheric effect happens does not diminish our enjoyment of the scene in front of us. In fact, many of us (not just photographers) seek out those scenes of natural beauty for renewal and relaxation.
Most people are innately drawn to moving water, much in the same way we are drawn to a small fire in a summer evening. Often, we look to locations with moving water as places for vacation. Oceans, lakes, rivers, and streams are certainly attractive destinations whether there is a distance to be traveled or if it be reasonably nearby. Water and fire can touch us on a deep primal level and draw us in ways that are too basic to even explain.
Streams and rivers flow downhill, usually toward a large body of water such as a lake or the ocean. Often the flow is gentle and steady. But as the slope that the water follows becomes steeper, the water moves faster. And sometimes the water becomes a waterfall that drops over a sudden precipice of a height ranging from a foot or two on up to hundreds of yards. In my mind, all waterfalls are beautiful but some are so impressive to everyone that they become world famous, such as Niagara Falls. No matter the height or the flow, waterfalls are natural features that attract attention. And often smaller waterfalls are found in shaded areas that can be a cooling refuge in the heat of summer.
Of course, waterfalls are a natural occurrence. Yet in many cases they can appear and feel magical. We are drawn to these locations, both as places of pure enjoyment and as settings for photography. Even casual photographers can take great photos of waterfalls because they are so beautiful. Most photographers will have many photos of waterfalls and will usually have a favorite image of a favorite waterfall. We often seek out the charm of waterfalls and want to spend as much time there as possible. The attraction is strong, innate, and undeniable. Go ahead, give in to that attraction and visit some waterfalls in the summer.