to be angry: to flare up in wrath, usually with the intent to punish
This is a strong word for anger that boils over. It is not a passing irritation but a burst of displeasure that expects to act, whether a king ordering an execution or God moving to judge. The same verb covers a person losing their temper and God's settled anger against wrongdoing, so the shade depends entirely on who is angry and why.
When a person is the one who is angry, the word paints a ruler or a leader whose fury lands on someone beneath them: Pharaoh with his officials, Moses with the priests, a foreign king with his queen. When God is the one who is angry, the same fury becomes his righteous reaction to sin, the anger that stands behind exile and disaster but that Scripture insists is not forever.
A related use turns the anger outward as a cause: to provoke someone to this wrath. Israel in the wilderness is repeatedly said to have made God this angry, treating his anger not as an accident but as something their rebellion deliberately kindled.
Because the anger so often issues in punishment, the word carries the sense of consequences on the way. To say God was angry in this sense is usually to say that judgment followed.