The hiking season for the AAT stretches from April to October, with snow lingering on the high passes in Carinthia and Slovenia until June, and snowfall generally beginning again sometime in October.
However, given that the route covers terrain (and climates) ranging from the Hohe Tauern to the Adriatic coast and takes up to six weeks to walk, the window for getting through the whole thing in one go is more limited – start too early, and you’ll find some of the high areas in Austria and Slovenia seriously buried under snow; arrive in the lower areas during the middle of the summer and you’ll find the weather oppressively hot.
Not only that, mountain huts start closing in October, as do some pensions and guesthouses; and the peak holiday season, August, can get extremely busy – not so much with people hiking the AAT, but with people holidaying in the area and possibly hiking shorter routes – with some accommodation providers reluctant to offer rooms for a single night. See this guide to Austria in summer for more information.
Walking in Nockberge National Park © Franz Gerdl, Kaernten Werbung
On balance, the best time for tackling the whole route in one stretch is to start at Kaiser-Franz-Josefs-Höhe in late August or even early September, thus avoiding the busiest time in August; getting through the Carinthian and most of the Slovenian sections, as well as the circular section through Italy’s Tarvisio region, by early to mid October; and completing the coastal section, where the weather will still be pleasant but not too hot, around the end of October. Those picking off the route over several trips, a week or two at a time, can obviously choose an appropriate season more easily.
Nevertheless having said all that I’ve walked different sections of the route in most months between April and January, including late October in the Nockberge when I was often the last guest of the season in mountain huts, but enjoyed the most beautiful weather and walking conditions of any of my visits to the Alpe-Adria Trail.
It’s difficult to give a short list of highlights for a route this long and diverse – and assuming you’re walking the whole route, you’ll see the whole lot anyway – but in terms of mountain scenery, nothing on the route touches the Nockberge Mountains in Austria (Stages 12–13 and 15–16), the Trenta and Soča valleys in Slovenia (Stages 23–25), the Tarvisio region in Italy (Circular Route Stages 3–6) and the view of the Grossglockner and the Pasterze glacier in Austria (Stage 1). Other highlights include: the route through the Groppensteinschlucht gorge on Stage 7; the border crossing over the Karavanke Mountains between Austria and Slovenia on Stage 23; and the lovely Brda region on the border between Slovenia and Italy. Gmünd and Cividale are the two most beautifully preserved old towns on the route, each very different and both fascinating in their own right.
Gmünd – one of the most beautiful towns on the trail © Kuenstlerstadt Gmuend, Kaernten Werbung
For those not able to walk the whole 750km route in one go – a commitment of up to six weeks – the obvious way to approach the AAT is to split it between two, three or more trips, which will allow you to complete the route within the framework of several ‘normal’ length summer holidays. The route lends itself quite well to this, with good transport links taking you in and out from the route and making it easy to just pick up where you left off the previous trip. Furthermore walking the route in several shorter, one- or two-week trips makes it easier to fit within the best time of year for hiking in that particular area.
There are various ways you could break the route into more manageable chunks – taking into account convenient transport links, as well as keeping each section cohesive (so, the first half of the Möll Valley in one trip, all of the Nockberge in one trip, all of the main route through Carinthia in one trip, etc.).
1. Stages 1–22 (Kaiser-Franz-Josefs-Höhe – Kranjska Gora)
2. Circular Route stages C1–C6 (Faaker See – Kranjska Gora) followed by stages 23–37 (Kranjska Gora – Muggia)
1. Stages 1–16 (Kaiser-Franz-Josefs-Höhe – Bad Kleinkirchheim)
2. Stages 17–21 (Bad Kleinkirchheim – Faaker See) followed by Circular Route stages C1–C6 (Faaker See – Kranjska Gora)
3. Stages 22–37 (Faaker See – Muggia)
1. Stages 1–6 (Kaiser-Franz-Josefs-Höhe – Mallnitz)
2. Stages 7–16 (Mallnitz – Bad Kleinkirchheim)
3. Stages 17–22 (Bad Kleinkirchheim – Kranjska Gora)
4. Circular Route stages C1–C6 (Faaker See – Kranjska Gora)
5. Stages 23–28 (Kranjska Gora – Cividale)
6. Stages 29–37 (Cividale – Muggia)