I saw that temper and mood are synonym, but actually I've never heard someone who says "I have a good temper" so I'm not sure about the using of "temper" instead of "mood". It will be beneficial to get an opinion of native English speaker about it.
Not exactly. I have a good temper or I am good-tempered means that I don't get angry easily; if I have a bad temper or am bad-tempered it means the opposite. (Also, if I lose my temper it means that I get angry when I tried not to; if I keep my temper it means that I managed not to lose it, despite being provoked.)
Now, I'm in a good mood (note that we don't say I have a good mood) means that I'm feeling happy at present; I'm in a bad mood means the opposite. Also, a person who is moody is someone whose mood changes easily, from good to bad and back again.
So, a person's mood (the mood that a person is in) is how they feel at a given time, whereas a person's temper is how they control their anger in general.
As Oxford Dictionary says:
- The way you are feeling at particular time;
- A period of being angry or impatient;
- The way a group of people feel about sth.
- A person who has temper becomes angry very easily;
- A short period of being angry;
- The way you are feeling at particular time.
As you can see it depends in which situation you are using the words.
Also, you can make some phrases with mood and temper like:
In a good mood, Bad-tempered,... etc.
In my opinion, it will be helpful for you to see the following links:
For idioms and phrases, connected with the words.
If you have questions you can ask me as a comment. :)