AUSTIN (KXAN) – You may think that the chance of rain is the probability that it will rain at all that day. So, there’s a 20% chance that rain will develop near you and an 80% chance it won’t rain.

But it’s a little more complicated than that.

At KXAN, we forecast the weather for 15 counties. When we say on TV that there is a 20% chance of rain, we’re saying that 20% of land in Central Texas is going to see rain. If that happens, 80% of the land in those 15 counties would stay dry.

Here’s why:

If people were scattered evenly all over Central Texas, 20% of people would see rain that day. The trouble is, more than half of our population is in just one county, which makes predicting the chance that you will get rained on more difficult. So the next time you hear a forecaster say there is high chance of rain, and you don’t see a drop, remember that the land elsewhere probably did.