Hello!!
Perhaps someone from Iceland can tell me about this. Hope so.
In order to avoid problems with flight delays, I'm thinking of moving my trekking from August 8th-12th to August 21st - 25th.
In principle I am not expecting a dramatic change in the weather by doing this. Am I right?
Please bear in mind that, if the volcano allows it, the final stage of the trek would be to go from Thorsmork to Skogar through Fimmvorduhals pass, which is a bit higher than Laugavegur...
Do you think that the possibility to have much snow in the pass will increase a lot just 2 weeks later? Should I take any winter gear? (snow shoes, crampons) Sorry if this a very stupid question, but I heard that the weather can get worse easily near september...
:-)

Hi, I think 2 weeks will not cause dramatic change in weather.
However, when you talk about winter gear... you should bring good gear to this hike. If it gets windy, it gets really cold even it is not below freezing point. You don't need crampons but have warm underwear and goretex-like jacket and trousers, high cut (?) hiking shoes and maybe tex-legwarmers (?). Hat and mittens! (sorry I don't know all the right words in english, so I put a question mark when not sure)
Volcano-permitting or not, I don't know about the Fimmvorduhals pass. There is yet to find a good route around or through the new lava there. Just look at is as a bonus if it is possible to hike Fimmvörðuháls :)

In order to avoid problems with flight delays, I'm thinking of moving my trekking from August 8th-12th to August 21st - 25th. In principle I am not expecting a dramatic change in the weather by doing this. Am I right?
My general observation is that the weather does often seem to be worse in the later part of August. Though of course on any specific year it could turn out to be horrible on any specific day whether mid-July or whatever. The potential for significant snow on the higher parts of the trek materially increases in the later parts of August, and there have been a few cases of quite material snowfalls in the last week of August in recent years, as early as about 24th. But, on the other hand, a violent storm of the variety that flattens/blows away tents can happen any time during the summer. And I've seen light dustings of snow on the hills even in July.
Should I take any winter gear? (snow shoes, crampons)
No. At that time of year the snow is probably mostly going to melt fairly soon after falling.

Wow! Thanks for so many quick answers!!!
:-)
Yes I am well prepared with gore-tex, gloves, and all the rest. I'm a regular mountaneer. I suppose this trek will not be exactly like Himalayas (I was there last summer) but I will definitely not underestimate arctic weather!!
Thanks again!
BF
«from Thorsmork to Skogar through Fimmvorduhals pass»
If the volcano is active I doubt you can do that route.
The area is closed for now.

"«from Thorsmork to Skogar through Fimmvorduhals pass»
If the volcano is active I doubt you can do that route.
The area is closed for now."
Below you will find the information shown in the Icelandic Touring Association website. Now I think about it, I think I will open a new thread and include this information, as it is of general interest for the people following this forum...
:-)
ATTENTION
Information for those who plan to hike the hiking routes Laugavegur, Fimmvörðuháls and/or stay in Thorsmork this summer.
The Icelandic Touring Association ( FÍ ) , Útivist Travel Association and Hostelling International Iceland, in co-operation with the public authorities, are preparing the re-opening of the route to Thorsmork.
A few weeks ago, the track to Thorsmork was badly damaged by floods, due to the eruption in Eyjafjallajökull. The tracks in the area are now being repaired and will be re-opened within a few weeks.
Given stable conditions in the area, Laugavegur trail will be open this summer, despite the eruption. Fimmvörðuháls-trail will also re-open this summer. Work is in progress to mark a new route over the fresh lava where it crosses the hiking trail.
Travellers are encouraged to be well equipped for hiking in the area. Sturdy hiking boots, warm and weatherproof clothes are needed, along with a picknic lunch and a First-Aid kit. Due to the eruption, it is important for all travellers to obtain up-to-date information about any changes in the area and a current weather forecast - Hut wardens will provide you with information.
Good work, begopo!
Just keep in mind that eruption is not over yet and might affect the trip.
I would also read (and remember) this post
http://icelandweatherreport.com/2010/05/is-the-eyjafjallajokull-eruption-over.html

Thank you ruslendingur!
Of course I will never leave marked paths or explore new lava on my own!! Life is too short...
:-)
Well, let's hope that the eruption has really stopped. Not for us (who would be happy to have the oportunity to witness such an incredible thing) but for the people living in Iceland, the farmers and people living in Vik, Skogar...
We will see.
Bye!!