The three most popular sources for the UK long range weather forecast are:
MetOffice Long Range Weather Forecast
The Met Office long range weather forecast offers an outlook for the UK for the next 6 to 30 days. It includes a medium range summary, 6 – 15 days and a long range summary, 16 – 30 days.
The Weather Outlook Long Range Weather Forecast
The Weather Outlook’s long range weather forecast for the UK covers 17 – 30 days with regional forecasts for; South England, Midlands, North England, Wales, Scotland, Northern Ireland and the Republic of Ireland. Using computer model data, the forecast gives an indication for daily weather conditions in each region. The long range weather forecasts from The Weather Outlook include; maximum temperature, minimum temperature, wind speed and direction and atmospheric temperature.
Netweather Long Range Weather Forecast
Netweather publish seasonal weather forecasts for Spring, Summer Autumn and Winter as well as a monthly outlook. The monthly outlook includes; rainfall, sun and temperature charts, plus a weekly summary for each of the coming four weeks.