Word of the Day: Vagaries
You can listen to the pronunciation here.
Vagaries are unpredictable or unexpected changes. The singular form is vagary, but the plural use is more common. You can see how much more common on the google ngram viewer here, if you're interested!
The vagaries of the weather at the time of year mean that it is difficult to decide what to wear.
The vagaries of my mother's mood are very upsetting; she gets angry for no reason at all.
Due to the vagaries of my job description, I am very stressed out.