This is Swedish even if it is a kind of old one. The message is a regular vacation greetings and I translate it into this.
(My english are not perfect so I beg your parden for that).

"Hi Ida and Britt,
How are you doing, well we hope.
Now can you see where we are in the sunny Florida, enjoying the summer and warm weather. Here is so hot and nice and we have seen so much beautifull things down here.
We came down the 17th and left home the 12th. We drove slowly the whole way and there was ice between the mountains, they where very tall.
We are going to stay here to the 1:st of April.
Greetings to the both of you.
Abel & Mathilda.

Mats Viking