Whatever the weather is like one should be happy.

Today is China's Valentine's day. Maybe I should go on a date with a boy, or go crazy with friends? but I chose to stay at with my sister's because it's too hot outside and nobody will go out to play with me. It's so disappointing. But However, I was able to do something significant. I like handicrafts, especially those which are made by myself, so I spent a whole afternoon making handicrafts, and that is my achievement.

Be happy whatever the weather is like

Today is Chinese Valentine's day. Maybe I should go on a date with a boy, or go out and be crazy with friends. I chose to stay at home with my sister because it's too hot outside and nobody wants to go out to play with me. It's so disappointing (or I am disappointed).But I was doing something significant. I like handicrafts especially making them, so I spent a whole afternoon making handicrafts. This is what I accomplished today.

Using achievement in this context doesn't sound natural. By saying "This is what I accomplished today" it still sounds like you spent a lot of time on it, and in a sense "achieved" something. :)

Be happy whatever the weather is like.

Today is chinese's valentine's day.Maybe I should have a date with a boy,or be crazy with friends,but I choose to stay with my sister .Because it's so hot outside that nobody will go out to play with me.It's so disappointed.But I did something significate anyway--I like handicrafts, especially those  made by myself.So I spent a whole afternoon making handicrafts,and these are my achievements.