Absolutely! Just like every other crop, variances in a number of factors will affect the end product. Rainfall, amount of sunshine and evening temperature are some of the factors which affect both the quality and quantity of juice obtained.
Take Merlot for example. Grown from the same vines, same soil can result in a fairly different juice from one year to the next. Additional sunshine may result in larger grapes (water) yet lower acid, sugar and tannin content – all key ingredients in a balanced wine. A hot dry season will do exactly opposite!
Some producers will adjust the juices to ensure consistency. However, not all producers will do this, hence the French term "Appelation controlee". You’ve heard the expressions "a great vintage", "an average year" etc. Those are referencing how the different factors affected the grape, and therefore the resulting wine.