30 degrees latitude what is the Winter snowline (altitude)?

At any latitude and all else equal, the so-called snowline's maximum altitude is ~1200' above ground level.

So you are saying One needs to be over 9000 feet that far south. Darn!

Sierra Blanco 12003 feet in the center of New Mexico was snow caped about 4 weeks per year, perhaps 30 degrees North latitude. It is about 50 miles North, North East of Alamagardo, New Mexico

On the other side of the big pond, you'll have to be in Moroccan Atlas mountains to see a snow-line at lattiude 30 N. To get a three months snow-line, you'll have to go above 3,000 meters AMSL. Sometimes even the Moroccan Riff mountains are snow covered and the roads are closed but it doesn't last very long. But if you sit on the terasse of the Cafe du Glacier, place Jemma El Fna in Marrakesh, you can see, during the winter, the white tops of the Altas mountains.