What's That Shimmering?
Stella Trebels | September 17, 2026
Have you ever been outside and look over to see what appears to be a shimmering lake where there shouldn’t be one? This is called a mirage. Mirages occur when hot ground warms the air just above it. The hot air bends the light rays differently than cooler air, and it creates a wavy, blurry appearance over the ground.
A heat dome can be a reason that you can see these mirages. A heat dome is formed when an area of high pressure in the atmosphere stays over the same region for a prolonged period of time. As a result, hot air is caught underneath the pressure system, and cool air cannot enter. An average heat dome will last for up to four days, but some can last for two weeks. On rare occasions, it can last even longer.
The heat dome warms the ground and the air just above it causing a mirage. That is the source of the non-existent, shimmering lake just above the ground.