Cyclocross is a very specific type of bike racing. For the most part, the course is off-road but there are sometimes portions of pavement included in the course. You can expect to encounter grass, dirt, mud, gravel, sand, and a whole slew of other assortments and combinations. The races are based on a set time (measured by numbers of laps), not distance. Depending on your category, a race can be as quick as 30 minutes (for beginners), or as long as 60 minutes (for pros).
In most cases, race officials wait to see how quickly riders complete the first lap before deciding how many total laps will be completed. Depending on course conditions and pack motivation, the total time may be a few minutes less or more than the race flyer lists. Courses are twisty circuits that are a minimum of 1.5 miles and a maximum of 2 miles long.
Courses typically, but not always include barriers, as well as other ‘features’ that will necessitate hopping both off, and back onto, your bike. Officially, these barriers are considered obstacles that are no more than 15 ¾ inches tall, and 13 to 20 feet apart. With very few exceptions, barriers are small enough for everyone to safely run through. Those brave (and skilled) enough can hop their bikes right over.
Often there are hills, sand pits and muddy sections that are too difficult or slow to ride, and thus a racer will shoulder their bike and run with it.
It is a fall and winter sport, with the first crop of races usually popping up in early September, followed by Nationals, and the World Championships in January. This means that if you look outside and see rain, snow, sleet, or shine, the show will still go on.