Temperature

Warm summer temperatures are increasing the average water year temperatures, which began on October 1, particularly on the Colorado Plateau where temperatures mostly ranged from 45 to 55 degrees Fahrenheit (Figure 1a). Elsewhere, the northern half of New Mexico remains between 40 and 55 degrees F and the high elevations of the Sangre de Cristo Mountains in northern New Mexico remain the coolest in the region, hovering between 35 and 40 degrees F. The southwest deserts of Arizona have averaged between 60 and 75 degrees F, while temperatures along the southern border of New Mexico have been between 55 and 65 degrees F. In many regions, warm nighttime temperatures caused by increased humidity have been responsible for warm average summer temperatures. Amazingly, however, these temperatures are still 0–3 degrees F cooler than average across the entire southwestern United States (Figure 1b).  The southeastern corner of Arizona and the White Mountains have been the lone holdouts, seeing 1–3 degrees F warmer-than-average temperatures. The cooler-than-average water year temperatures reflect the influence of the cold and wet El Niño event during last winter.

During the past 30 days, temperatures throughout New Mexico and across southern Arizona have been 0–2 degrees F above average (Figures 1c–d). The warmest conditions have been in northeastern New Mexico, while parts of central and northern Arizona have been than average. These cooler temperatures are the result of monsoonal thunderstorms that have been quite isolated, leaving southeastern Arizona uncharacteristically dry in recent weeks.