Many fixtures can be found in the calendar below, which can be filtered by type of race (Road, XC, Track and field).
Avon County Athletics Association produces a list of local road and off-road races the latest version of which, Version 150 is available below:
England Athletics also publish regular fixture lists for endurance events. The winter fixture list for 2019/20 is below. Most of these dates (eg for local XC leagues) should also be found on the calendar above.