Writing in English should not be a problem. Check the AndesWeb Snow Report Page . Sometimes snow falls heavily in May and June. If the snow is good, you'll have excellent skiing and riding, few crowds and lower prices. Snow is usually good in July, but South Americans have Winter vacation during this month.
Resorts become more crowded, and prices are at their highest.
August is usually the month with the best snow and weather. It is also less crowded than July. September usually has good snow, but conditions are sometimes spring like. Crowds are usually small. October is a good month for Spring skiing and riding.