Temperature

Temperatures since the water year began on October 1 are averaging between 65 and 75 degrees Fahrenheit in the southwest deserts and along the Arizona-California border, 60 to 65 degrees F in southeastern Arizona and in southern New Mexico, and 45 to 60 degrees F in central and northwestern New Mexico and Arizona (Figure 1a). The highest elevations have experienced average temperatures, between 40 and 45 degrees F, that are within 1 degree F of average across the northern half of Arizona and northwestern New Mexico (Figure 1b). Southern Arizona and central New Mexico generally have been 1–2 degrees F warmer than average, while eastern New Mexico has been 2–4 degrees F warmer than average.

In the last month, the persistent high pressure ridge over Texas that was present in July and August has lingered into September, bringing record-high temperatures to Texas, New Mexico, and Arizona. Temperatures during the past 30 days have been 2–4 degrees F warmer than average across most of the Colorado Plateau of Arizona and northern New Mexico; temperatures in southern and western Arizona and southern and eastern New Mexico have been 4–6 degrees F warmer than average (Figures 1c–d). High temperatures in the region are in part caused by the position of the high pressure ridge, which has been parked farther east than normal, suppressing monsoon precipitation in many parts of the Southwest.