Like any astronomical enterprise, we are subject to the weather. The following services may be of assistance. If you know of others, please email the webmaster with a description and links.
Based in China. Allows to define locations by geographical coordinates. Reliable forecasts (which are hard in any case!) maybe 75% of the time.
An international website which can be customised for individual predefined locations (e.g. cities; example link for Wellington – see below). This forecast is in average pretty good and provides hour-by-hour forecasts and some basic astronomical data.
Cloud Free Night is a non-profit online weather forecast information service, for the benefit of the Australian and New Zealand astronomy community. It is unique in offering a comparison of the widely available forecasts from the United States GFS global model with higher resolution forecasts from the Australian Bureau of Meteorology ACCESS model. The Cloud Free Night website has also been optimised for mobile devices.
Andrew Cool started SkippySky in 2008 as a free service to amateur astronomers, but these days all sorts of people use it. It provides regional cloud cover predictions and maps at 3-hour intervals. Custom maps can be arranged.
Provides sun/moon rise/transit/set, twilights, moon phases for any location, and much more.