why is there lightning but no rain

The reason there can be lightning but no rain is due to a phenomenon called a "dry thunderstorm." In dry thunderstorms, the rain droplets do form and fall from the thunderstorm clouds, but the rain evaporates in the dry air before it reaches the ground. This happens when the clouds are high enough and the humidity between the clouds and the ground is very low, causing the precipitation to disappear before touching the surface. Lightning, however, can travel through the dry air and still be observed along with thunder, even though no rain is felt on the ground. Dry thunderstorms are common in hot, dry regions and are especially dangerous for triggering wildfires because the lightning can ignite dry vegetation without the mitigating effect of rainfall. This explains why lightning can be seen without rain during certain weather conditions.