The wind on the fells can have a major impact on air temperature, and should not be underestimated, below is a chart showing just how much of a difference the wind speeds can make. Wind speeds also increase with altitude, the speed on the top of the fell can easily be double that at sea level.
| 
                                 
                                    Wind (Mph)
                                   
                                 | 
                              
                                 
                                    Temperature (Celsius)
                                   
                                 | 
                            |||||||
| 
                                 | 
                              
                                 
                                  10
                                 
                               | 
                              
                                 
                                  5
                                 
                               | 
                              
                                 
                                  0
                                 
                               | 
                              
                                 
                                  -5
                                 
                               | 
                              
                                 
                                  -10
                                 
                               | 
                              
                                 
                                  -15
                                 
                               | 
                              
                                 
                                  -20
                                 
                               | 
                              
                                 
                                  -25
                                 
                               | 
                            
| 
                                 
                                  10
                                 
                               | 
                              
                                 
                                  5
                                 
                               | 
                              
                                 
                                  -1
                                 
                               | 
                              
                                 
                                  -7
                                 
                               | 
                              
                                 
                                  -13
                                 
                               | 
                              
                                 
                                  -19
                                 
                               | 
                              
                                 
                                  -25
                                 
                               | 
                              
                                 
                                  -31
                                 
                               | 
                              
                                 
                                  -37
                                 
                               | 
                            
|---|---|---|---|---|---|---|---|---|
| 
                                 
                                  20
                                 
                               | 
                              
                                 
                                  0
                                 
                               | 
                              
                                 
                                  -6
                                 
                               | 
                              
                                 
                                  -13
                                 
                               | 
                              
                                 
                                  -20
                                 
                               | 
                              
                                 
                                  -27
                                 
                               | 
                              
                                 
                                  -34
                                 
                               | 
                              
                                 
                                  -41
                                 
                               | 
                              
                                 
                                  -48
                                 
                               | 
                            
| 
                                 
                                  30
                                 
                               | 
                              
                                 
                                  -1
                                 
                               | 
                              
                                 
                                  -9
                                 
                               | 
                              
                                 
                                  -16
                                 
                               | 
                              
                                 
                                  -24
                                 
                               | 
                              
                                 
                                  -31
                                 
                               | 
                              
                                 
                                  -39
                                 
                               | 
                              
                                 
                                  -46
                                 
                               | 
                              
                                 
                                  -54
                                 
                               | 
                            
| 
                                 
                                  40
                                 
                               | 
                              
                                 
                                  -2
                                 
                               | 
                              
                                 
                                  -10
                                 
                               | 
                              
                                 
                                  -18
                                 
                               | 
                              
                                 
                                  -26
                                 
                               | 
                              
                                 
                                  -34
                                 
                               | 
                              
                                 
                                  -41
                                 
                               | 
                              
                                 
                                  -49
                                 
                               | 
                              
                                 
                                  -57
                                 
                               | 
                            
| 
                                 
                                  50
                                 
                               | 
                              
                                 
                                  -3
                                 
                               | 
                              
                                 
                                  -11
                                 
                               | 
                              
                                 
                                  -19
                                 
                               | 
                              
                                 
                                  -27
                                 
                               | 
                              
                                 
                                  -35
                                 
                               | 
                              
                                 
                                  -43
                                 
                               | 
                              
                                 
                                  -50
                                 
                               | 
                              
                                 
                                  -58
                                 
                               | 
                            
| 
                                 
                                  60
                                 
                               | 
                              
                                 
                                  -3
                                 
                               | 
                              
                                 
                                  -11
                                 
                               | 
                              
                                 
                                  -19
                                 
                               | 
                              
                                 
                                  -27
                                 
                               | 
                              
                                 
                                  -35
                                 
                               | 
                              
                                 
                                  -43
                                 
                               | 
                              
                                 
                                  -50
                                 
                               | 
                              
                                 
                                  -58
                                 
                               | 
                            
| 
                                 
                                  70
                                 
                               | 
                              
                                 
                                  -3
                                 
                               | 
                              
                                 
                                  -10
                                 
                               | 
                              
                                 
                                  -18
                                 
                               | 
                              
                                 
                                  -26
                                 
                               | 
                              
                                 
                                  -34
                                 
                               | 
                              
                                 
                                  -42
                                 
                               | 
                              
                                 
                                  -50
                                 
                               | 
                              
                                 
                                  -57
                                 
                               | 
                            
| 
                                 
                                  80
                                 
                               | 
                              
                                 
                                  -2
                                 
                               | 
                              
                                 
                                  -10
                                 
                               | 
                              
                                 
                                  -17
                                 
                               | 
                              
                                 
                                  -25
                                 
                               | 
                              
                                 
                                  -33
                                 
                               | 
                              
                                 
                                  -40
                                 
                               | 
                              
                                 
                                  -48
                                 
                               | 
                              
                                 
                                  -56
                                 
                               | 
                            
| 
                                 
                                  90
                                 
                               | 
                              
                                 
                                  -1
                                 
                               | 
                              
                                 
                                  -9
                                 
                               | 
                              
                                 
                                  -16
                                 
                               | 
                              
                                 
                                  -24
                                 
                               | 
                              
                                 
                                  -31
                                 
                               | 
                              
                                 
                                  -39
                                 
                               | 
                              
                                 
                                  -46
                                 
                               | 
                              
                                 
                                  -54
                                 
                               | 
                            



































































































