In the past few days I have noticed that org-weather from https://github.com/kautsig/org-weather was no longer working. It appears that OpenWeather now requires you to get an API key. You can get a free one by registering.
As a temporary horrible hack you can update org-weather-api-url in org-weather.el to include your API key: (defvar org-weather-api-url "http://api.openweathermap.org/data/2.5/forecast/daily?q=%s&mode=json&units=metric&cnt=7&&APPID=YourKeyGoesHere") Obviously it would be better if this was a configurable variable, probably read from your .emacs. -- Best wishes, Ian.