The weather in the English Lake District is notoriously fickle with Seathwaite, in the heart of Borrowdale, and only 9 miles from Keswick being officially the wettest inhabited place in the United Kingdom experiencing around 3,552 millimetres (140 in) of rain per year.
Prospective participants in the X-Lakes event should therefore be prepared for the possibility of rain and for wind conditions to prevent flying. However, the Lakes are also famous for rapid change in weather conditions. It is common to get a window of opportunity for flying even when forecasts look terrible.
Based on statistical analysis of historical hourly weather reports and model reconstructions from 1980 to 2016 we choose to run the X-Lakes event early in May. The following graphics help to explain this choice.
The day with the lowest chance of rain over the 36 years of records has been 22nd April when the chance of rain is 28% (It will still rain on more than one in four occasions on this date!)
However, we choose to pitch the X-Lakes event a little later than this in order to favour better odds for flying.
Radiant energy and thermal activity
Thermal strength is still building throughout May and doesn’t level off until mid to late June.
Wind direction is not really an issue in the Lake District with any number of ridge systems that will allow inventive transitions across the main mountain ranges.
It is interesting to note, however, that the prevailing westerly wind direction occurs with the least frequency in the early part of May.
Clearly in mountain areas wind speed is important for safety in the air.
The X-Lakes will generally set a latest landing time that ensures all pilots can be accounted for well before dark. In early May sunset occurs well after 8.30pm and allows competitors to race for many hours on each day.