About Cologne: Practical Tips
Voltage
In Germany, the electrical voltage is 240 volts with a frequency of 50 Hz. Plugs have two round pins and metal lashes for the grounding conductor. Normally adapter plugs are available at the airports or large hotels. Power cut-offs are very rare.
Drinking Water
Drinking water is no problem at all; it is free from bacteria and chlorine. Usually Cologne’s problem is having too much water not too little.
Payment
Larger restaurants accept international credit cards, as do all ATMs. Note that most of the German banks will charge a fee for providing you with cash from the ATMs. The ticket vendor machines inside trains and buses often accept only coins or German bank cards (“GeldKarte”).
As always, you should be aware of pick-pockets, especially at the square in front of the cathedral and the near-by shopping streets. It was recently reported that PIN-numbers are being spied out with cameras. Covering the keyboard pad with the other hand avoids this.
Weather
Whether due to man-made climate change or not, summers have become hotter and more capricious during the last 20 years. At the beginning of July in some years temperatures may exceed 30°C (86°F) during the day, while other summers are rainy and have temperatures around 17°C (63°F). Cologne lies in a depression formed 30 million years ago when the region was a bay ("Kölner Bucht") on a prehistoric sea. As a result, Cologne is relatively protected from prevailing winds, and therefore can be quite muggy in the summer.
More Information
Read more about driving etc. in "About Cologne: Travelling"