Weather forecasting for an upland area such as the Peak District is not an easy task. All published forecasts for the area are likely to be of very variable reliability, especially for periods beyond 24 hours ahead.
The Met Office issues a “Mountain Weather Forecast” for the Peak District. This covers a 5-day period and is issued twice daily, in the early hours of the morning and in the late afternoon. In practice, though, the early morning issue is usually only a repeat of the forecast issued the previous afternoon but with a new time of issue. Therefore, in reality there is usually only one issue of this forecast per day, in the late afternoon. This should be borne in mind if using it in the morning. The forecast does have the advantage of being produced, at least in part, by a human forecaster. The following link takes you to the most recent issue:
Site specific weather forecasts generated entirely by computer are available from a number of sources. It is best not to rely on just one source as the reliability is very variable. If you use forecasts from two independent sources and both are making similar predictions then that gives some degree of confidence. In my experience two of the better sources are the UK Met Office and the Norwegian Meteorological Service. The following links are useful. (Click the “back” button or arrow on your browser if you want to get back to this page after viewing one of the forecasts).