Mountain Bike National Championships happen year-round depending on country and discipline, but a majority of the cross country championships, among countries in the northern hemisphere, happen in July, with many on the third weekend of that month.
Late September is when many nations will hold their marathon national championships, as suggested by the UCI, while a few nations will wrap up their marathon championships at other times of the year.
Below is an updated index of the 2013 MTB National Championship coverage on Cyclingnews. Click on the appropriate link to access coverage for cross country, downhill, four cross, eliminator and marathon disciplines.
Australia: Cross country, eliminator and downhill, marathon
Austria: Cross country
Belgium: Cross country
Canada: Cross country, downhill, marathon
Czech: Cross country
Denmark: Cross country
France: Cross country and downhill
Germany: Eliminator, cross country, marathon
Great Britain: Marathon, cross country, downhill
Italy: Cross country, marathon
Netherlands: Cross country
New Zealand: Cross country and downhill
Spain: Cross country and downhill
South Africa: Marathon, cross country and downhill
Sweden: Cross country
Switzerland: Cross country and eliminator
United States of America: Marathon, cross country and short track, downhill and dual slalom