America's Most Extreme Weather Cities 2017; Through September, at Least 37 Locations on Pace for Record Warmth

Several United States cities have had an extreme year in terms of temperatures, precipitation or both.

With help from the Southeast Regional Climate Center (SERCC), we examined locations in the U.S. with at least a 60-year period of record without missing data to find out which places were the warmest, coolest, wettest and driest in 2017 through the end of September.

January-through-September temperature departures from 1981-2010 average, in degrees Celsius, over North America and adjacent areas.

(NOAA/ESRL Physical Sciences Division)

The Warmest

If we simply listed the warmest locations based on straight temperatures, it would be obvious. Puerto Rico, the U.S. Virgin Islands, Hawaii, South Florida, South Texas and the Desert Southwest would lead the pack every year.
Instead, we examined the anomalies, or departure-from-average temperatures. The more often temperatures were above average and the greater those departures were above average, the greater the anomaly over the year.
Warmer-than-average temperatures were widespread during the first nine months of the year from the North Slope of Alaska to the Southeast.
One typically frigid place has been highest above average so far in 2017.

Top Five U.S. 2017 Warm Temperature Anomalies Through September
Relative to 1981-2010 Averages
(Source: SERCC)

City	Temperature Anomaly (degrees F)
Utqiagvik (Barrow), Alaska	+5.0
Parsons, West Virginia	+4.6
Salina, Kansas	+4.6
Smithfield, North Carolina	+4.5
Augusta, Georgia	+4.3

Utqiaġvik, formerly known as Barrow, chalked up its third-warmest January-through-September period in 2017 after crushing its previous record-warm year in 2016 by 1.9 degrees Fahrenheit (just over 1 degree Celsius).
Fifteen of the top 25 warmest temperature departures in the nation were in the South, including Austin (Bergstrom), Texas (+4.0 degrees), Charlotte, North Carolina (+3.5 degrees), and Nashville, Tennessee (+3.5 degrees).
According to the SERCC, 37 U.S. locations with at least 60 years of records tied or set new a record-warm January-through-September period. See the tweet below for the complete list.
Cleveland, Montgomery, Alabama, and Pensacola, Florida, each set record-warm years in 2016, and have also had a record-warm first nine months of 2017.
Columbia, South Carolina, has set record-warm years in both 2015 and 2016 and is also on pace for record warmth in 2017.

The Coolest

Using the SERCC analysis tools, it was difficult to find many locations in the U.S. that were cooler than average in 2016.
Of the 878 locations in the SERCC's analysis, we could find only 21 locations with at least 60 years of records and didn't have any data gaps that were cooler than average so far in 2017.
The large majority of these cool anomalies were in either southern Alaska or the Northwest.
Compared to the bullish warm anomalies we listed above, these cool anomalies were paltry.

Top Five U.S. 2017 Cool Temperature Anomalies Through September
Relative to 1981-2010 Averages
(Source: SERCC)

City	Temperature Anomaly (degrees F)
Kenai, Alaska	-2.6
Iliamna, Alaska	-1.7
Cordova, Alaska	-1.1
Richland, Washington	-1.1
Burns, Oregon	-1.0
Pendleton, Oregon	-1.0

The Wettest

Again, simply taking straight rainfall doesn't tell the whole story of which areas far exceeded what is typical.
The nation's biggest precipitation overachievers in 2017 were generally in two zones: the Gulf Coast, including Florida, and parts of the West.

Top Five U.S. 2017 Wet Anomalies Through September
Relative to 1981-2010 Averages
(Source: SERCC)

City	Precipitation Anomaly (inches)
Beaumont/Port Arthur, Texas	+45.27
Houston, Texas	+36.06
Blue Canyon, California	+29.98
Pensacola, Florida	+27.11
Ketchikan, Alaska	+27.04

Hurricane Harvey's record-smashing rain left its imprint on this list. Beaumont/Port Arthur, Texas, more than doubled its previous wettest calendar day record, and Houston experienced two of its five wettest calendar days on record during Harvey in late August.

Evacuees wade down a flooded section of Interstate 610 as floodwaters from Tropical Storm Harvey rise Sunday, Aug. 27, 2017, in Houston.

(AP Photo/David J. Phillip)

Also reflected in the top five was the record-setting winter and spring wet season in northern California, and a Florida Gulf Coast city repeatedly plagued by heavy rain events – Pensacola.
Despite having not taken a single hurricane strike so far during a frenetic 2017 hurricane season, Pensacola's January-through-September rainfall topped the same period in 2005 by over 2.5 inches, when Hurricane Dennis and a more distant Hurricane Katrina hammered the northern Gulf Coast.
In addition to Beaumont/Port Arthur, Houston, and Pensacola, eight other cities have had a record-wet January-through-September. The two Florida cities on the list below were soaked by Hurricane Irma, among other heavy rain events in 2017.

• Alamosa, Colorado
• Alpena, Michigan
• Gainesville, Florida
• Hugoton, Kansas
• La Junta, Colorado
• Naples/Bonita Springs, Florida
• Reno, Nevada
• Trinidad, Colorado

The Driest

While the northern High Plains has so far suffered the nation's worst drought of 2017, a developing flash drought late in the summer spread from parts of the Plains to the Upper Midwest.
This developing heartland flash drought was reflected in three of our top five dry precipitation anomalies through the year's first nine months.

Top Five U.S. 2017 Dry Anomalies Through September
Relative to 1981-2010 Averages
(Source: Southeast Regional Climate Center)

City	Precipitation Anomaly (inches)
Hilo, Hawaii	-32.35
Yakutat, Alaska	-14.23
Ottumwa, Iowa	-10.88
Salina, Kansas	-9.33
St. Joseph, Missouri	-8.81

The top two cities on the list occupy those spots because, to some extent, they're both typically among the wettest cities in the U.S. However, rainfall in Hilo, Hawaii, tailed off sharply after February. As of late September, the Big Island of Hawaii was in moderate to extreme drought.
Given the lack of typical precipitation, what isn't reflected in the top five list above is the northern Plains and northern High Plains.
Glasgow, Montana (5.24-inch deficit), Havre, Montana (5.23-inch deficit), and Minot, North Dakota (7.61-inch deficit), each had the driest year-to-date through September.
The northeast Montana town of Glasgow shattered its previous record-driest January-through-September period from a Dust Bowl year – 1936.

Drought monitor analysis as of Sept. 26, 2017. The worst areas of drought, analyzed in the darker red and brown contours, are indicated in the northern High Plains.

(USDA/NDMC/NOAA)

Oddly enough, a snowstorm the first week of October downed trees, knocked out power and dumped a two-day record October snowfall on drought-stricken Havre, Montana.




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