I am often asked this question, so in the interests clarity about ambiguity and uncertainty...
Something is ambiguous if it can be interpreted or seen in more than one way. So for example a sentence in a job reference "you will be very fortunate to get this person to work for you" has a couple of different interpretations. Either the subject of this reference is very good or very lazy.
Uncertainty on the other hand is any situation in which an individual has or finds doubt. So a situation could be uncertain but not ambiguous. People can have doubt about the most certain of situations and no doubt about an ambiguous situation. Uncertainty is then also a perception and an individual experience.