When best to apply for tourist visa to China

You can apply for China visa in December. Please apply for a visa about one month in advance of your intended date of entry into China, and do not apply three months earlier than your intended date of entry into China. You should take upon yourself any consequences resulting from your failure to submit visa application at an appropriate time, which may lead to either your already-issued visa becoming expired or it would be too late to get a visa before your planned departure date.