The Uniformity of Nature is a presumption that the future will be like the past. If it is conceded to be a true reflection of reality, it can form the basis of inductive reasoning. Thus, we can make plans to get up and go to work tomorrow morning, because we can make the reasonable assumption that today will be the same as yesterday, or at least as much like it as to render it unnecessary to consider the differences. Actually in this example, it would be more accurate to say that tomorrow will be the same as the corresponding day last week. But the principle is the same.
When one considers this presumption closely, there seems no particular reason why it should be so. Why should nature not undergo complete and radical changes every five minutes? When the laws of nature and even the names of the days of the week change beyond all recognition? Someone might argue that, if this were to happen, we would notice it happening. However, that argument does not stand, because if our brains and sensory capacities, being part of nature themselves, underwent the same radical changes, our perception of reality might well have the same relational connection to natural events and processes as they have before. So we would be unaware that anything had happened.
There's another objection also. It is called Goodman's Paradox of Induction. I make no claim to understand it fully, but essentially it says that although we experience Nature as a uniformity over time, it is undeniably true that individual, particular objects do undergo changes. Now if we examine an object and then try to predict its state of being at some future specified time, there is equal support for the hypothesis that at that time it will be the same as now, or the hypothesis that it will be different from now.
Therefore the presumption of the Uniformity of Nature is not really as helpful as most people would like to think, since the only time it is fulfilled is when it works, and it is unfulfilled when it doesn't. Which leads the philosopher to the following aphorism:
Don't bother trying to predict the future.