Moving to Oslo in July

July is a very slow month but the essentials are still functioning. You can buy groceries and get electricity and internet and a telephone. Smaller shops like my local candle boutique are closing for the summer though, but it's pretty pointless to buy many candles this time of year anyway cuz it's so bright.

As for utilities, most places in Oslo are already wired for internet, so getting your utilities set up takes almost no time at all if you know who previously had the utilities in their name there. If not, apartments have a number on the door frame that identifies the individual place in larger buildings. With that information you can usually just sign up remotely. I had to pick up a router for my current internet but it was same-day service start.

however, the tricky part is that this is all assuming you have a national ID number. I don't know how it works if you don't.

regarding housing, I found an apartment in two days and I could have moved into it immediately, but I hear I was lucky. Start looking now to identify what neighborhoods you want and what the prices are. Good places tend to go quickly so it's helpful to know what you're looking for.

Many thanks ECS ! I wish I could be as lucky as you with the apartments 
BTW can you please recommend few good expat suburbs that are pretty close to t-bane stations?

What do you mean by an expat suburb?

I used to live in Drammen which has a large population of people from all over the world living there, and a train station. Is that an expat suburb?  Or do you mean somewhere like Bekkestua which is near the international school?