Aside from the first frost on the windshield in the morning, the second most defining indicator of the arrival of fall is when all the leaves of the mulberry trees coming raining down after the first real frost of the year. That was this morning (Nov 12)in my neighborhood. While Albuquerque had officially seen its first freeze back on Nov 6 the first leaf- clearing frost did not come until last night
The National Weather Service has a nice page showing the timing of first freezes of the year for Albuquerque and the rest of NM. For Albuquerque the earliest freeze date (1931-present)is Oct 8. Other locales in the Albuquerque area have recorded freezes much earlier with the earliest being Sep 4 1961 in the South Valley. Locations of weather stations can have a big affect on low temperatures as cold air tends to drain downhill to pool in the lowlands.
At the Sevilleta the station with the lowest lows and the earliest freezes is almost always South Gate (Met41) station near the south boundary which sits in Valle del Ojo de la Parrida. The earliest recorded freeze there was Sep 18, 2006. For other stations on the refuge the date of the first freeze has come much later- as late as Oct 17th at the Ladron Station. This figure shows the first, last and average first freeze dates for the 7 weather stations with the longest records. The first freeze data for this year is also included.
It seems obvious that we have been working on the late end of the freeze date spectrum this year. While a couple of the Sev stations have had later first freeze dates, 4 out of the 7 stations set new first freeze records. In a related matter this figure shows how this past October had the warmest average low temperatures in its 121 year official record. At the same time the average daily high temperatures were near average.