In 2016, the main land of the United States average temperature was 54.9°F, 2.9°F above the 20th century average. This was the second warmest year recorded for the mainland, behind 2012 when the annual average temperature was 55.3°F. The last year with a below-average temperature was 1996.
This year started with one of the strongest El Niños on record ushering in Pacific moisture and some much needed drought relief to parts of the West. High elevation snowpack and valley rains hit the west and by late winter 2016 the snowpack across the region were near to and above average. While above-normal precipitation was common across the West, it generally fell short of values often observed during strong El Niño winters.
Regardless, the regional drought footprint did contract, from 45.2 % at the beginning of the year to 21.5% by the end of the year. A strong and persistent ridge in the West limited the number of storms that reached central and southern California where drought conditions were worst. The abnormal warmth of the El Niño in the late winter/early spring period prematurely melted some of the early season snowpack gains across the Sierra. Therefore, exceptional drought conditions remained throughout the year much of the West, and California. It took into this winter for most of California to recover from the drought of the last 5 years and much of southern California remains abnormally dry, yet.
Precipitation also saw regional extremes in the rest of the country. As is typical with a strong El Niño episode, precipitation across much of the West was above normal for the year. California’s precipitation was 3.27 inches above the 20th century average and Washington state’s precipitation was 7.36 inches above average. Several Upper Midwest states were much wetter than normal for the year. Both Minnesota and Wisconsin had their second wettest year on record while the northeast and much of the south (that missed the fall flooding) were dry.
Generally speaking, precipitation was above average for much of the mainland of the United States west of the Mississippi, while drier-than-average conditions existed for much of the Southeast and Northeast. Locally, the recent rains have provided a pattern of steady but slow drought recovery in the Northeast and Mid Atlantic for the last couple of months. Less than 1% of Virginia remains in drought and the U.S. groundwater monitoring well up the road from my house has recovered to normal levels after recording two of the lowest levels in its 85 year history last fall.
I participate in a citizen science project that measures precipitation in the United States.