How to get here...
…from Frankfurt airport
From Frankfurt Flughafen Regionalbahnhof you either take S8 (Direction Wiesbaden Hbf) or Regionalbahn to Mainz Hbf. They usually leave every half hour from regio-platform 3. The ride takes about 25 minutes and costs appr. 4 €.
When using the ticket automat, you should click on "Mainz/Wiesbaden", then "single ride", and then "via Rüsselsheim" (the cheaper of the two fares). The ticket is also valid for a possible bus connection in Mainz.
Alternatively, from Frankfurt Flughafen Fernbahnhof you may take an IC or ICE to Mainz. They usually leave from platform 5 or 7, the ride takes about 20 minutes and costs appr. 10 €.
…from Frankfurt Hahn airport
From Airport Frankfurt Hahn take the ORN-Bus to Mainz Hbf. The bus leaves about every two hours, the ride takes 70 minutes and costs 12 €. Tickets can be bought on the bus.
…from Mainz main station
From Mainz Hauptbahnhof (main train station) take the bus number 6 or 6A (direction “Universität”, there are also many other bus lines) and get off at the stop “Universität” (2nd stop). You can buy a ticket for 1.50 € from the bus driver. Tell him where you want to go and that this corresponds to no more than three stops in order to get that cheap rate: The ride from the railway station to the University is a “Kurzstrecke”, meaning short-distance ride. Now follow the map to the “Alte Mensa”.
Weather
In early September we enjoy the last days of summer in the region with temperatures typically around 20 °C and infrequent rain. In the evenings, temperatures can drop down to around 5–10 °C. For up-to-date information please take a look at: http://www.mainz.de/WGAPublisher/online/html/default/mkuz-5xwb9e