We have arrived in Duluth and our hats are impeccable

I do not speak Swedish, but here's my very faulty sort-of translation:

Many thanks for the postcard which I had the joy of receiving. I [heard?] your Papa was sick. I hope that he is healthy again. We all feel good as far as I know. I was with Mrs. Erickson yesterday and her husband was  hearty. A few of them (or us?) went to the poor farm on Sunday.  For March it was the nice weather, but now it's raining. It's Sunday so we'll soon be home under the roof. Have you heard from [Pa?]  Greetings from a friend Otikia (?)

So, based on what I've learned about life amongst the Swedes circa 1910, I'd say this was at least in part a church mission trip.

Actually, I think I misread "man" instead of "han" and it's actually:  "I was with Mrs. Erickson yesterday and she was well." 

And of course, better wording would be: "It's Sunday so we'll soon be home under our own roof."

My dear HBH, you are a superstar!

My best guess on the postmark date is Jun 191?. I hope that helps.