桜がここでは!

桜がここでは! (I think, in this case, it's better to say 桜がさいた! or 桜の季節!, it's just my opinion.)

Yay! 今日私は桜がを見ました!
They're starting to bloom~
Vancouver has a lot of Cherry Blossom trees.
バンクーバーにはたくさんの桜をがあります。
It's so beautiful~
きれいです〜
But after it rains, the cherry blossoms die...
でも、後に雨は桜を殺す。。。:'(     (I can understand your sentence but it's more natural to say...)

 雨が降ると桜は散(ち)ってしまいます or おわってしまいます。

They're so delicate ;__; and it rains too often here LOL.

桜はとても繊細(せんさい)で...そのうえ ここではよく雨が降ります。
They only usually last a couple of weeks during the spring.

桜のきせつは、春のほんの2週間ほどでおわってしまいます。

I'll enjoy them while they're here~ :)

咲いているうちに(桜を見ることを)楽しみますね。

Hi Pearl, 

Here, in Tokyo, they are also starting to bloom though, around my apartment, they has not started to bloom yet. Yes! Enjoy seeing them! Have great time!