
There are lots of weather stations in the UK and elsewhere which freely publish their realtime weather data via the web. These have the potential benefit of being updated on a more regular basis than yahoo etc whcih would make any realtime app more feasible. Most of these websites don't offer standard api's to access the raw data but it does seem that they use a lot of similar software and hardware for their stations and hopefully this might make any app that I write work on more than one site (fingers crossed). In order to get access to the data I must scrape the data by reading in the HTML and parsing it to use. I found this service 'beautiful soup' that can read in and parse html and this is what I plan to use.
Here is a useful tutorial showing some basics of screen scraping
Tullig weather station outputs data as xml
WeatherLink map shows all the sites where people have a 'davis' weather instrument. The data is uploaded to a page and can be scraped

Rothampstead modellor I plan to try and work with to extend the tiger grass project