The weather forecast for Amsterdam is nearly the same as for De Bilt near Utrecht, which is representative of the densely populated area between Rotterdam and Amsterdam. A more poetic description is given below.
The winters in the Amsterdam area are usually perceived as "mild" to European standards. Mild but certainly nordic, which means average day temperatures around 2-6C, and light freezing nights. If the atmosphere is humid, snowfall ("wet snow") is likely. Apart from that, gusty winds are particularly experienced as unpleasant by the foreign visitor, especially as this introduces a (sometimes considerable) chill factor to the real temperature.
In rarer cases (but still not unlikely), winter has entered the land by the end of January, and temperatures may drop as low as -5/-10C during daytime and even colder overnight. This, however, comes with a good aspect, too, since these conditions only occur when the atmosphere is relatively dry. This means that proper clothing is the appropriate way to fight these conditions. As someone from the Far North once pointed out: "Bad weather does not exist. Only inappropriate clothing".
Electric plugs used un the Netherlands are Type C. Voltage is 230V and frequency is 50Hz. Please make sure to bring adapters with you as they will not be provided on site.
For any information regarding the event logistics contact Damir Rajnovic ("Gaus") on firstname.lastname@example.org or telephone +44-7715-546-033. During the event you can approach any of the designated Cisco personell on site for help.
If you would like to find any local information that will make your stay in Amsterdam more pleasant you can contact either Jan Meijer (email@example.com) or Jacques Schuurman (firstname.lastname@example.org).