I have posted about my Finnmarksvidda adventure in this topic
Finnmarksvidda (Norway) August 2011
I have been 1 timein Finnmarksvidda, so I do not consider myself "an expert"
The best period would be July. June is possible but is rather "early". August is also possible but that is already "late" in the season...
The winter lasts until May. That is when the snow and the ice start to melt. It is possible to catch trout and grayling in June but they will be skinny because they have just started to eat again after the winter. Perhaps in the end of June they are already a bit fatter and rounder. Try to find a river that holds char. Char favor colder conditions.
I was there in August and that was already "late". The water levels had already dropped quite a bit. But the fishing was Excellent (with capital E)! Large grayling and trout, but no char.
Finnmarksvidda is not very accessible. You need to know where you go and every place has its own rules. The general rule was/is that you can fish with a license within 6 km of public roads. If you want to further then you need a guide. Some places are only accessible with a guide. This lack of freedom is in contradiction with the traditional Norwegian "allemannsretten", but Finnmarksvidda is part of Lapland (Samen Country) and it seems that they are allowed to have special rules...
Please, don't go alone. At least 2 people. Consider a guide. Coverage for mobile phone is very good. If you have no signal at the river, then you have to go to a higher point on one of the nearby hills.
I have fished with several flies:
- czech nymps = no success
- other nymphs (pheasant tail) = some fish
- dry flies (sedges, klinkhammers) = good but small fish
- super puppan = no success
- streamers (stickleback imitations) = lots and lots of 50+ grayling and several trout
I have included a pattern of my most successful streamer. I got 95% of all my fish on it.
(sorry, I could not focus the camera on the fly, but set it full screen and have a good look at the initial image)
Now, you say that you want to go in June. I have heard that June is top period for sea trout in Alta bay. You could consider that for 2 or 3 days. Stay close to the river mouth. When conditions are good, then you can have 10-20 sea trout per day! So I have been told.