Climate Summary for 2010

With regard to temperature, 2010 was certainly a year of extremes. After experiencing the coldest winter since 1978, a sudden shift to positive temperature anomalies occurred in early April. The much warmer than average temperatures were also quite persistent. Most notably, every month from April through September was at least 2.3°F or more above normal in Athens, Atlanta, Columbus, and Macon. Incredibly, the summer (June-August) average temperature in Columbus was their warmest ever, while Athens tied their record from 1931. Comparably, Atlanta and Macon both experienced their 3rd warmest summer.

January began with the arrival of an arctic air-mass that dominated the first half of the month. A second cold outbreak by month’s end ensured the capital city of its coldest January since 1985. A monthly average temperature of 38.5°F was recorded and this was the first time the monthly average temperature was below 40°F since December 2000. Athens also achieved this distinction with a monthly average of 39.7°F. Departures from normal ranged from -2.5 degrees in Athens to -5.2 degrees in Columbus. Record rainfall on the 16th, 21st, and 24th contributed to monthly surpluses in all four cities. The 2.75” and 2.47” which fell on the 24th in Atlanta and Athens, respectively, represented more than half their normal January total. Departures from normal ranged from +0.35” in Atlanta to +1.51” in Athens.

The much colder than average temperatures continued through February with three more arctic blasts. For the 2nd consecutive month, Atlanta (39.6°F) and Athens (39.5°F) recorded an average monthly temperature below 40 degrees. This had not occurred in either city since December 1981 and January 1982. Negative departures from normal were even greater than in January, ranging from an impressive -6.4 degrees in Macon to a stunning -7.8 degrees in Columbus. When combined with December 2009, it was the coldest (December-February) in all four cities since the winter of 1977-1978. Precipitation was also below average in all four locations. Record and near record rainfall on the 5th, with 2.65” at Athens and 1.93” in Atlanta wasn’t enough to offset a drier than average month. Columbus and Macon posted the largest deficits of -0.92” and -1.48”, respectively. On the 12th, a low pressure system tracking across the northern Gulf of Mexico produced the heavy snow event of the winter. Snowfall totaled 4.5” in Athens, 3.6” in Atlanta, 3.0” in Macon, and 2.0” in Columbus.

Temperatures moderated a bit in March, but still remained well below average in all four cities. Although Athens recorded the smallest departure from normal with -1.9 degrees, both Atlanta and Macon tallied a chilly -3.6 degrees below normal, while Columbus with a -5.3 degree departure, tied their 4th coldest March on record. For the 3rd consecutive month, measureable snow fell in the capital city with 1.1” on the 2nd. The last time this occurred in the first 3 months of the year, was 1983. Again, monthly precipitation was below normal in the four cities with deficits ranging from -1.14” in Atlanta to -2.66” in Athens.

In April, La Nina evolved and strengthened in the equatorial Pacific. Characteristically, temperatures abruptly rebounded to well above average readings. Notably, record and near record warmth occurred early in the month. On the 5th, Athens set a new record high at 88°F, breaking the old record of 87°F in 1988. The next day, Atlanta broke their record with 86°F, eclipsing the previous of 85°F in 1929. By the end of April, departures averaged above normal in all four cities, led by Atlanta with 3.6 degrees and followed by Athens with 3.0 degrees. However, drier than average conditions continued for the 3rd straight month, as all four climate sites recorded rainfall deficits ranging from -1.06” in Atlanta to -2.23” in Columbus. The significantly above average monthly temperatures continued in May, as the capital city posted a departure of 3.6 degrees for the 2nd consecutive month. Others ranged from 2.9 degrees in Columbus to 3.4 degrees in both Athens and Macon. However, substantial rains returned with a half inch or more falling in one or more of the climate sites on the 3rd, 21st, 28th, 29th, and 30th. A potent storm system on the 3rd brought record daily rainfall to all four cities. Amounts ranged from a 2.00” soaking in Macon to a 4.77” deluge in Columbus. This contributed to well above average monthly rainfall in each city ranging from 4.31” (+1.33”) in Macon to 6.87” (+2.92”) in Atlanta.

Positive temperature anomalies increased again in June, as Atlanta and Columbus experienced their 2nd and 4th warmest June, respectively. Temperatures soared to record and near record highs on the 15th, as Macon set a new record with 100°F breaking the old record of 99°F set in 1963. Atlanta (95°F), Athens (98°F), and Columbus (98°F) all missed tying their record for the date by one degree. Consequently, monthly temperature departures ballooned to 4.6 degrees in Atlanta, 4.3 degrees in Athens, 3.5 degrees in Columbus, and 4.0 degrees in Macon. On a positive note, rainfall generally remained in abundance with all of the locations except Columbus recording surpluses for the 2nd straight month. Although, drier than normal by 1.06” in Columbus with 2.45” of rainfall measured for the month, Atlanta (5.21”), Athens (4.55”), and Macon (5.73”) were well on the plus side.

The unrelenting heat persisted through July and August with all four cities continuing their lengthy string of significantly warmer than normal monthly departures. In fact, the July departures ranging from 2.3 degrees in both Atlanta and Macon to 3.2 degrees in Athens increased in August to 3.8 degrees in Athens and Macon, 3.9 degrees in Atlanta, and 4.1 degrees in Columbus. To put these numbers in perspective, it was the 3rd warmest August on record for Atlanta and Athens, while Macon tied for their 5th warmest ever. However, Columbus was the standout by recording their warmest August on record with 85.4 F, surpassing the old mark of 85.2 F set in 2007. It was also their 3rd warmest month ever, placing behind only July 1993 and 1986 at 85.8 F. The broad, persistent ridge of high pressure stretching from Texas to New England which was responsible for this heat, also put rainfall at a premium from mid through late summer. Three out of the four cities posted rainfall deficits in each of these two months with amounts ranging from -0.75” in Atlanta to -3.01” in Athens for July, and from -0.22” in Macon to -1.33 in Columbus for August.

To add insult to injury, September brought little relief from the hot, dry pattern. Again, the four climate sites posted much warmer than normal monthly averages. Additionally, 13 record high temperatures were either tied or broken on 10 separate days in Atlanta, Columbus, and Macon. Columbus set an astonishing 8 record highs during the month. A notable few were 99°F on the 10th which broke the old record of 98°F in 2002, 98°F on the 20th breaking the previous record of 97°F in 1997, and 98°F on the 21st eclipsing the record of 97°F from 1990. By mid month, mild to moderate drought conditions expanded into much of south and west Georgia as the unusually dry, hot conditions continued; however, a late month, daily record rainfall on the 26th in Columbus and Macon helped to alleviate some of its presence. While 1.85” fell in Columbus, breaking the old record of 1.55” set in 1953, Macon received a drenching of 4.20” which shattered the previous record of 2.43”, also set in 1953. Monthly rainfall was still below normal in Atlanta by 2.49”, but Athens, Columbus and Macon replenished a bit with surpluses of 1.82”, 0.10”, and 2.19”, respectively.

After a scorching summer, two polar outbreaks occurring in late September and early October brought welcomed relief to north and central Georgia. Low temperatures fell into the 40s and 50s while daytime highs were generally held to the 70s. This reprieve didn’t last however, as record high temperatures returned in mid and late October. On the 11th, Atlanta reached 86°F tying the record set back in 1954. Then, on the 26th and 27th, five more records were set. On the 26th, Atlanta and Macon tied their records of 85°F and 87°F, respectively and both from 1940. Also that day, Columbus broke their previous record of 87°F in 1984, when the mercury reached 88°F. On the 27th, Columbus and Macon tied their record highs of 89°F set in 1984 and 88°F set in 1940, respectively. As a result, the monthly temperature departures weren’t as high above the normals as the previous six months, but were still well on the plus side at all four locations. They ranged from a modest 0.7 degrees in Macon to a very mild 2.5 degrees above average in Atlanta. With respect to rainfall, October leaned heavily to the dry side. Although, Atlanta received 3.33” which was slightly above the average by 0.22”, Athens, Columbus, and Macon all received paltry amounts. The 1.42” measured in Athens, and the miniscule 0.95” in Macon represented less than half their monthly average.

The arrival of two polar air masses in November resulted in bringing the average monthly temperatures closer to their 30 year normal. Despite Atlanta still being above average by 1.2 degrees, Athens (0.3 degrees), Columbus (0.7 degrees), and Macon (0.0 degrees) had moderated considerably. Additionally, monthly rainfall rebounded nicely with the help of a daily record rainfall in Atlanta, Athens, and Columbus on the 30th. Atlanta broke its 130 year record for the date (1.87”) with 2.26”, while Athens and Columbus broke theirs with 2.27” and 2.06”, respectively. The previous marks were 2.08” in 1914 for Athens and 1.69” in 1974 for Columbus. This was enough to push Atlanta and Athens over the top for the month by 1.38” and 1.20”, respectively.

2010 seemed to go from one extreme to another, and December was no exception. A series of arctic blasts in early, mid and late December brought record breaking cold temperatures and measurable snow to north and central Georgia. Six record lows were set on 4 separate days in Atlanta (1), Athens (2), Columbus (1), and Macon (2). On the 8th, the temperature dropped to 16°F in Athens breaking the old record of 20°F set in 2006. On the 10th, Macon recorded a low of 19°F breaking the old record of 20°F in 1995. Then, on the 14th, both Atlanta and Athens saw the mercury plunge to 14°F breaking their previous lows of 15°F in 1917 and 1942, respectively. Macon also broke their record low on the 14th, when 18°F surpassed 20°F from 1960. Columbus didn’t set a record low however until the 28th, when they tied their record of 23°F from 1977. Measurable snowfall was also in the picture and much of it was record setting. The Christmas snowfall of 2.0” in Athens established a new record as well as the 1.3” that fell the next day. Although, the 1.3” which fell in Atlanta on the 25th wasn’t a record, the 0.1” on the 26th was. It marked the first time snowfall had been recorded on this date. Macon also set a record for snowfall, when 0.1” accumulated on the 25th. None of this however, offset the precipitation deficits for the month which ranged from -1.79” in Athens to -2.85” in Macon. Although, the month ended on a mild note, average monthly temperatures were way below normal. Departures ranged between -6.3 degrees in Columbus to -7.4 degrees in Athens. With monthly averages of 38.3°F in Atlanta, 37.2°F in Athens, 42.8°F in Columbus, and 40.9°F in Macon, these ranked as the 6th, 3rd, 5th, and 4th coldest Decembers in each city, respectively. In each case, it was the coldest December since 2000.