What is the best way to deal with a 2.5 year old throwing tantrums, especially in public? Will this be a phase that will pass?

2.5 is really the toughest age. That’s why it’s called the terrible 2. She/he will get better in about 6 months. Hang in there. For me I handled the terrible 2s by ensuring she had enough sleep, was not over hungry and would tell her before hand exactly where we were going and what we were about to do. I realised staying away from surprises really helped her stay calm as she knew what to expect. I also made Sunday’s ice cream day. So if she behaved herself all week she would get an ice cream on Sunday.