Herrsching can be easily reached by plane, by train, and by car. For the time of the symposium, you will probably not need a car.
Arriving by Plane
The closest airport is Munich Airport (MUC), which offers direct flights to major international airports all over the world. There are car rental stations at the airport, but the symposium location can be easily reached by public transport. The public transportation system in Munich is called "MVV". The MVV comprises surface trains (S-Bahn), underground trains (U-Bahn), and buses. You will only need the S-Bahn. Note that also the S-Bahn goes underground in the inner city. The following map shows the S-Bahn and U-Bahn-connections.
The airport is located at the top right side of the above map. Herrsching is located at the lower left side of the map. It's the terminal station of the line S5. There are basically two options to go to Herrsching from the airport. The easiest option is to take the S8 until somewhere between Ostbahnhof and Pasing. There you step out of the train and just step into the next S5 (you do not have to change the platform). The duration is 1 hour and 33 minutes. A slightly faster but also slightly more complicated option is to take the S1 until Laim. There you have to change the platform and step into the next S5. This takes 1 hour and 24 minutes.
The cheapest ticket is a single ticket (4 zones) for 8.80 Euro. But you are on the safe side, if you take a daily ticket (Single-Tageskarte Gesamtnetz) for 9.60 Euro, or, for two people, a partner daily ticket (Partner-Tageskarte Gesamtnetz) for 17.00 Euro.
Arriving by Train
If you arrive by train, you should leave the train already at Pasing, and not wait until main station (Hauptbahnhof). From both stations, you step directly into the S5. A single S-Bahn ticket to Herrsching (3 zones) costs 6.60 Euro. (Note, however, that you can make your booking at your departure station directly until Herrsching. In this case you will not need an additional MVV ticket.)
Arriving by Car
For those who arrive by car, we do not provide driving directions here, because professional route planners, like www.viamichelin.com do a much better job in this respect. The address of the symposium location, the Ammersee-Hotel is: Summerstr. 32, 82211 Herrsching.
Weather
Nothing can be said about the weather in June. You can have sunny days with max. temperatures as high as 35°C (95°F) during the day and 25°C (77°F) in the night, but it can also be raining all the day with min. temperatures of 15°C (60°F) during the day and 10°C (50°F) during the night. The most probable weather is sunny/cloudy with 25°C (77°F) during the day and 20°C (68°F) during the night.