I can't tell you much about January. I've only been to Mazatlan in December. In December it can get a little chilly; the same December week can be considerably warmer in Puerto Vallarta. I would assume January would be warmer. One of the weather sites (can't remember if it is accuweather or wunderground) should have some historical weather data for January in Mazatlan. The red flags are frequently up on the beach in front of Torres--at least in December. It is a beautiful beach--not white sand, but still beautiful. You can walk north or south a long way. The Torres staff rakes the beach each day. There are usually taxis waiting directly in front of the resort. Also, the bus stops directly in front of the resort; there are even benches provided for waiting. Before you go, check out maztravel.com and download the bus route map and print it in color. The restaurant at Torres is excellent and affordable. Happy hour is a great hit every day. The staff seems to make it their goal for you to have a wonderful vacation at their resort. Reviews for Torres are excellent both on TUG and on tripadvisor.com. Personally, I wouldn't even think of renting a car there. Taxis/pulmonias and buses are everywhere, and the cost is minimal.