2001 Atlanta, Georgia (ATL)

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2001 ATLANTA, GEORGIA (ATL)

Atlanta is located in the foothills of the southern Appalachians in north–central Georgia. The terrain is rolling to hilly and slopes downward toward the east, west, and south so that drainage of the major river systems is generally into the Gulf of Mexico from the western and southern sections of the city and to the Atlantic from the eastern portions of the city.

The Gulf of Mexico and the Atlantic Ocean are approximately 250 miles south and southeast of the city, respectively. Both the Appalachian chain of mountains and the two nearby maritime bodies exert an important influence on the Atlanta climate. Temperatures are moderated throughout the year while abundant precipitation fosters natural vegetation and growth of crops. Summer temperatures in Atlanta are moderated somewhat by elevation but are still rather warm. However, prolonged periods of hot weather are unusual and 100 degree heat is rarely experienced.

With the mountains to the north tending to retard the southward movement of Polar air masses, Atlanta winters are rather mild. Cold spells are not unusual but they are rather short–lived and seldom disrupt outdoor activities for an extended period of time. Late March is the average date of the last temperature of 32 degrees in the spring and mid–November is the average date of the first temperature of 32 degrees in the fall, which gives an average growing season of about 234 days.

Minimum dry precipitation periods occur mainly during the late summer and early autumn. Maximum thunderstorm activity occurs during July, but severe local thunderstorms occur most frequently in March, April, and May, some spawning highly damaging tornadoes.

The average annual snowfall varies widely from year to year. A fall of 4 inches or more occurs about once every five years. Most snows melt in a short period of time due to the rapid warming which often follows the storm. Ice storms, freezing rain or glaze, occur about two out of every three years, causing hazardous travel and disruption of utilities. Severe ice storms occur about once in ten years, causing major disruption of utilities and significant property damage.

The Bermuda High pressure area has a dominant effect on Atlanta weather, particularly in the summer months. East or northeast winds produce the most unpleasant weather although southerly winds are quite humid during the summer. The generally light wind conditions contribute to the formation of an occasional early morning fog.

NORMALS, MEANS, AND EXTREMES

ATLANTA, GA (ATL)

LATITUDE: LONGITUDE: ELEVATION (FT): TIME ZONE: WBAN: 13874

33 38′ 25″ N  84 25′37″W  GRND: 971 BARO: 974  EASTERN (UTC + 5)

ELEMENTPORJANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECYEAR
TEMPERATURE FNORMAL DAILY MAXIMUM3050.455.064.372.779.685.888.087.181.872.763.454.071.2
MEAN DAILY MAXIMUM5652.056.563.872.780.386.288.787.882.072.962.854.071.6
HIGHEST DAILY MAXIMUM53798089939510110510298958479105
YEAR OF OCCURRENCE194919961995198619961952198019951954195419611991JUL 1980
MEAN OF EXTREME MAXS.5669.472.980.085.089.694.395.794.691.784.277.270.883.8
NORMAL DAILY MINIMUM3031.534.542.550.258.766.269.569.063.551.942.835.051.3
MEAN DAILY MINIMUM5633.736.342.650.859.566.669.969.364.052.542.635.752.0
LOWEST DAILY MINIMUM53-85102637465355362830-8
YEAR OF OCCURRENCE198519581960197319711956196719921967197619501983JAN 1985
MEAN OF EXTREME MINS.5614.819.225.935.146.556.663.962.551.037.626.618.738.2
NORMAL DRY BULB3041.044.853.561.569.276.078.878.172.762.353.144.561.3
MEAN DRY BULB5642.946.453.161.870.076.579.278.673.062.852.844.961.8
MEAN WET BULB1738.942.647.453.962.569.072.171.265.953.348.638.855.3
MEAN DEW POINT1732.035.039.346.657.264.668.567.861.848.242.732.949.7
NORMAL NO. DAYS WITH:
MAXIMUM 90300.00.00.00.11.08.011.69.23.00.00.00.032.9
MAXIMUM 32301.70.3*0.00.00.00.00.00.00.0*0.52.5
MINIMUM 323016.712.85.10.50.00.00.00.00.00.24.913.253.4
MINIMUM 0300.20.00.00.00.00.00.00.00.00.00.0*0.2
H/CNORMAL HEATING DEG. DAYS3074456636513827000101383676362991
NORMAL COOLING DEG. DAYS3000833157330428406241541001667
RHNORMAL (PERCENT)3068636261677074757468686868
HOUR 01 LST3073696969778085858378757476
HOUR 07 LST3078767878828488908884817982
HOUR 13 LST3059545149535660606053555856
HOUR 19 LST3062565450576066666763636461
SPERCENT POSSIBLE SUNSHINE6349545866686762646266585060
W/OMEAN NO. DAYS WITH:
HEAVY FOG (VISBY 1/4 MI)674.83.32.71.41.31.01.51.62.02.23.14.229.1
THUNDERSTORMS671.22.03.54.25.98.49.97.53.11.01.00.748.4
CLOUDINESSMEAN:
SUNRISE-SUNSET (OKTAS)17.22.43.2
MIDNIGHT-MIDNIGHT (OKTAS)16.43.2
MEAN NO. DAYS WITH:
CLEAR12.01.010.012.09.0
PARTLY CLOUDY11.06.09.0
CLOUDY13.02.011.02.03.0
PRMEAN STATION PRESSURE (IN)2829.0228.9928.9328.9328.9228.9328.9728.9828.9829.0229.0229.0228.98
MEAN SEA-LEVEL PRES. (IN)1730.1330.1030.0530.0130.0030.0030.0430.0230.0430.1030.1330.1530.06
WINDSMEAN SPEED (MPH)5610.410.610.710.18.88.17.77.28.18.59.29.89.1
PREVAIL. DIR (TENS OF DEGS)3732323230302729080808323232
MAXIMUM 2-MINUTE:
SPEED (MPH)637483844373846393228333248
DIR. (TENS OF DEGS)26260603013231073532302926
YEAR OF OCCURRENCE199720012001199619961998200119961999199919962000FEB 2001
MAXIMUM 5-SECOND:
SPEED (MPH)648704652455161594036434370
DIR. (TENS OF DEGS)25262832272831253332292626
YEAR OF OCCURRENCE199620012000199619971998200119971999199919962000FEB 2001
PRECIPITATIONNORMAL (IN)304.754.815.774.264.293.565.013.663.423.053.864.3350.77
MAXIMUM MONTHLY (IN)6710.8212.7711.6611.868.379.9917.718.6911.6411.0415.729.9217.71
YEAR OF OCCURRENCE193619611980197919801991199419671989199519481961JUL 1994
MINIMUM MONTHLY (IN)670.840.771.860.490.320.160.570.500.04T0.410.69T
YEAR OF OCCURRENCE198119781985198619361988199519761984196319391979OCT 1963
MAXIMUM IN 24 HOURS (IN)673.915.675.745.585.134.226.475.055.877.274.113.857.27
YEAR OF OCCURRENCE197319611990197919481991199419401992199519351961OCT 1995
NORMAL NO. DAYS WITH:
PRECIPITATION 0.013011.79.810.78.49.49.912.09.37.86.39.110.0114.4
PRECIPITATION 1.00301.31.51.91.21.01.01.50.91.11.11.21.315.0
SNOWFALLNORMAL (IN)301.00.60.4T0.00.00.00.00.00.00.10.22.3
MAXIMUM MONTHLY (IN)648.34.47.9T0.00.0T0.00.0T1.03.08.3
YEAR OF OCCURRENCE19401979198319902001199319682000JAN 1940
MAXIMUM IN 24 HOURS (IN)648.34.27.9T0.00.0T0.00.0T1.02.88.3
YEAR OF OCCURRENCE19401979198319902001199319681993JAN 1940
MAXIMUM SNOW DEPTH (IN)539440000000129
YEAR OF OCCURRENCE19481979199319752000JAN 1948
NORMAL NO. DAYS WITH:
SNOWFALL 1.0300.30.20.10.00.00.00.00.00.00.00.*0.10.7
PRECIPITATION (inches) 2001 ATLANTA, GA (ATL)
YEARJANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECANNUAL
19729.263.164.492.314.284.043.812.781.863.043.967.6250.61
19738.893.449.534.037.143.352.101.354.160.752.318.1155.16
19745.366.372.443.723.833.204.646.261.061.223.895.3147.30
19756.198.988.314.284.625.528.523.302.995.314.623.3666.00
19765.151.8410.951.496.992.364.290.500.723.554.114.0145.96
19773.492.146.281.772.043.034.264.234.905.007.182.3646.68
19787.030.772.633.497.282.862.565.660.941.422.963.7541.35
19795.035.713.1911.862.431.463.627.286.082.175.190.6954.71
19805.692.6911.661.888.374.490.761.594.771.612.141.2946.94
19810.846.623.932.063.892.692.742.765.273.011.856.2541.91
19824.756.993.796.022.606.096.311.453.005.834.155.2356.21
19833.094.996.684.791.421.521.851.067.521.977.469.2751.62
19844.665.975.836.626.570.7411.216.460.041.542.103.6555.39
19854.114.981.862.754.692.049.924.572.635.744.232.2849.80
19860.882.464.130.492.952.183.276.083.685.156.203.0340.50
19875.636.135.441.162.746.367.351.223.020.702.364.1346.24
19884.643.322.576.061.710.165.044.926.355.004.871.2145.85
19892.574.303.855.246.429.347.652.1311.641.713.974.4963.31
19908.479.758.362.765.261.393.494.643.016.121.273.0457.56
19914.663.106.985.287.359.995.824.372.030.393.192.6955.85
19923.583.943.811.031.734.149.035.048.552.8410.046.3860.11
19933.944.435.732.774.876.013.052.963.913.834.012.5448.05
19945.113.765.773.682.162.4417.714.165.864.513.271.5960.02
19953.366.742.663.002.123.970.575.822.5211.047.403.5752.77
19968.263.826.422.912.121.702.144.664.320.893.224.1444.60
19975.657.932.184.283.363.914.711.324.835.123.345.0551.68
19985.837.106.255.121.233.582.935.544.450.261.971.9046.16
19995.331.973.321.144.425.833.431.264.192.413.342.2138.85
20004.891.263.632.631.861.112.704.034.930.885.022.6235.56
20012.773.619.083.293.316.692.541.032.190.790.872.2238.39
POR=53 YRS4.744.685.473.943.623.834.743.863.412.683.334.2448.54
AVERAGE TEMPERATURE (F) 2001 ATLANTA, GA (ATL)
YEARJANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECANNUAL
197246.842.652.461.366.572.276.877.774.661.149.648.360.8
197341.442.857.457.665.075.678.977.475.664.755.644.261.4
197453.245.857.861.171.072.577.976.770.261.352.444.362.0
197547.247.150.559.871.075.376.477.970.363.354.043.461.4
197638.551.556.461.765.473.876.476.069.856.244.239.859.1
197729.342.055.363.069.977.179.577.773.559.654.342.160.3
197833.739.351.661.567.676.378.678.376.362.558.546.160.9
197937.341.756.262.770.175.778.880.172.762.454.346.761.6
198044.941.952.162.672.079.185.183.878.961.551.944.963.2
198139.546.851.867.767.681.382.277.772.460.254.539.161.7
198238.547.456.558.472.576.379.177.570.562.753.749.961.9
198340.444.451.356.467.874.081.481.470.862.151.539.960.1
198439.647.551.758.167.578.376.877.571.369.850.653.761.9
198536.344.256.864.069.977.578.477.672.566.462.041.462.3
198643.449.854.462.971.080.084.177.474.664.057.945.163.7
198741.945.753.260.373.277.881.082.074.159.755.748.862.8
198839.245.554.963.070.078.680.581.073.459.355.046.662.3
198949.747.556.862.968.876.979.879.472.964.254.339.162.7
199049.854.457.761.970.478.680.680.675.764.456.549.165.0
199144.349.256.265.972.876.781.079.274.864.651.049.163.7
199245.151.854.061.968.174.580.276.173.261.951.544.561.9
199347.045.251.759.471.179.385.482.176.763.353.945.363.4
199440.550.157.467.669.480.579.179.173.964.158.350.464.2
199546.346.458.965.874.477.084.380.771.062.047.742.863.1
199641.147.150.661.274.979.181.879.573.263.452.048.862.7
199746.751.160.657.764.871.578.976.673.361.847.842.961.1
199846.047.050.359.072.778.980.777.875.665.956.750.063.4
199948.049.850.565.168.974.979.281.973.162.556.747.163.1
200043.150.957.358.672.977.981.479.770.864.151.037.262.1
200141.750.850.463.570.074.478.678.871.360.759.850.162.5
POR=53 YRS43.346.253.161.469.776.578.978.173.362.952.544.961.7

REFERENCE NOTES:

PAGE 1:

THE TEMPERATURE GRAPH SHOWS NORMAL MAXIMUM AND NORMAL MINIMUM DAILY TEMPERATURES (SOLID CURVES) AND THE ACTUAL DAILY HIGH AND LOW TEMPERATURES (VERTICAL BARS).

PAGE 2 AND 3:

H/C INDICATES HEATING AND COOLING DEGREE DAYS.

RH INDICATES RELATIVE HUMIDITY

W/O INDICATES WEATHER AND OBSTRUCTIONS

S INDICATES SUNSHINE.

PR INDICATES PRESSURE.

CLOUDINESS ON PAGE 3 IS THE SUM OF THE CEILOMETER AND SATELLITE DATA NOT TO EXCEED EIGHT EIGHTHS (OKTAS).

GENERAL:

T INDICATES TRACE PRECIPITATION, AN AMOUNT GREATER THAN ZERO BUT LESS THAN THE LOWEST REPORTABLE VALUE.

+ INDICATES THE VALUE ALSO OCCURS ON EARLIER DATES.

BLANK ENTRIES DENOTE MISSING OR UNREPORTED DATA.

NORMALS ARE 30–YEAR AVERAGES (1961–1990).

ASOS INDICATES AUTOMATED SURFACE OBSERVING SYSTEM.

PM INDICATES THE LAST DAY OF THE PREVIOUS MONTH.

POR (PERIOD OF RECORD) BEGINS WITH THE JANUARY DATA MONTH AND IS THE NUMBER OF YEARS USED TO COMPUTE THE MEAN. INDIVIDUAL MONTHS WITHIN THE POR MAY BE MISSING.

WHEN THE POR FOR A NORMAL IS LESS THAN 30 YEARS, THE NORMAL IS PROVISIONAL AND IS BASED ON THE NUMBER OF YEARS INDICATED.

0.* OR * INDICATES THE VALUE OR MEAN–DAYS–WITH IS BETWEEN 0.00 AND 0.05.

CLOUDINESS FOR ASOS STATIONS DIFFERS FROM THE NON–ASOS OBSERVATION TAKEN BY A HUMAN OBSERVER. ASOS STATION CLOUDINESS IS BASED ON TIME–AVERAGED CEILOMETER DATA FOR CLOUDS AT OR BELOW 12,000 FEET AND ON SATELLITE DATA FOR CLOUDS ABOVE 12,000 FEET.

THE NUMBER OF DAYS WITH CLEAR, PARTLY CLOUDY, AND CLOUDY CONDITIONS FOR ASOS STATIONS IS THE SUM OF THE CEILOMETER AND SATELLITE DATA FOR THE SUNRISE TO SUNSET PERIOD.

GENERAL CONTINUED:

CLEAR INDICATES 0–2 OKTAS, PARTLY CLOUDY INDICATES 3–6 OKTAS, AND CLOUDY INDICATES 7 OR 8 OKTAS. WHEN AT LEAST ONE OF THE ELEMENTS (CEILOMETER OR SATELLITE) IS MISSING, THE DAILY CLOUDINESS IS NOT COMPUTED.

WIND DIRECTION IS RECORDED IN TENS OF DEGREES (2 DIGITS) CLOCKWISE FROM TRUE NORTH. "00" INDICATES CALM. "36" INDICATES TRUE NORTH.

RESULTANT WIND IS THE VECTOR AVERAGE OF THE SPEED AND DIRECTION.

AVERAGE TEMPERATURE IS THE SUM OF THE MEAN DAILY MAXIMUM AND MINIMUM TEMPERATURE DIVIDED BY 2.

SNOWFALL DATA COMPRISE ALL FORMS OF FROZEN PRECIPITATION, INCLUDING HAIL.

A HEATING (COOLING) DEGREE DAY IS THE DIFFERENCE BETWEEN THE AVERAGE DAILY TEMPERATURE AND 65 F.

DRY BULB IS THE TEMPERATURE OF THE AMBIENT AIR.

DEW POINT IS THE TEMPERATURE TO WHICH THE AIR MUST BE COOLED TO ACHIEVE 100 PERCENT RELATIVE HUMIDITY.

WET BULB IS THE TEMPERATURE THE AIR WOULD HAVE IF THE MOISTURE CONTENT WAS INCREASED TO 100 PERCENT RELATIVE HUMIDITY.

ON JULY 1, 1996, THE NATIONAL WEATHER SERVICE BEGAN USING THE "METAR" OBSERVATION CODE THAT WAS ALREADY EMPLOYED BY MOST OTHER NATIONS OF THE WORLD. THE MOST NOTICEABLE DIFFERENCE IN THIS ANNUAL PUBLICATION WILL BE THE CHANGE IN UNITS FROM TENTHS TO EIGHTS (OKTAS) FOR REPORTING THE AMOUNT OF SKY COVER.

HEATING DEGREE DAYS (base 65 F) 2001 ATLANTA, GA (ATL)
YEARJULAUGSEPOCTNOVDECJANFEBMARAPRMAYJUNTOTAL
1972-730031364655117256172402307202999
1973-7400186295639357531241155502310
1974-750026148381633547493451192202873
1975-7600281133426658143842651244842787
1976-77001027761877510996403001021103832
1977-780041783137019667144121375703482
1978-79000112194580853646279971602777
1979-80005122320559616668399113302805
1980-810018154391618786502410364302958
1981-820017179314795819486282204203098
1982-8300161393414667555714232612402996
1983-8400321234007707805034092215003288
1984-850013224263468825762651111412656
1985-860015711317256634223311331402505
1986-870112107243609709534359191602771
1987-88000172279494791559310104602715
1988-890001882915664684902841604402491
1989-9000291033187974622972501502002426
1990-91001210925248863643728154802277
1991-92008764194996113773451615022548
1992-9300121103986275485494171841302858
1993-94006129346604753412245552002570
1994-9500079207446573515207591102097
1995-960025135514680735517437159803210
1996-9700410438949756138515622663182403
1997-980051595086795804994651751233085
1998-990005324246351942144392802241
1999-00007110246548669401232186002399
2000-01001686428856715391446108503051
2001-0026172163452
COOLING DEGREE DAYS (base 65 F) 2001 ATLANTA, GA (ATL)
YEARJANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECANNUAL
1972003567222737039629725701453
197300111578322438388323792001674
1974012442198229405368187411101506
197500644195313359406193632101600
1976018306727335934615911001254
19770035117136745640326617101735
19780024014434642842034540711773
197900133318132743647524349501762
19800444922742863258944051002424
198100912413149454039824636401982
198220251324334644639419273861748
19830031011827851551221240001688
198400221132405372397210178121720
19850018881723814234012481194901899
1986001174208455599401300833402165
19870026026639150253128112622053
19880054916941649050225818001907
1989073610117036446745227385601961
199005266619441549048834198202125
1991002089258358502446305704132065
199201137315529247834926520001646
1993001122208435639536364801902314
19940219141167470445447274601302038
199500239131136860849421147202155
19960825432242952745625564722126
19973328136222143836626468001466
19980016425742649440732388352023
199900010313630544653125639101817
20000034253396515464196641601911
200100069166288429435224451301669
SNOWFALL (inches) 2001 ATLANTA, GA (ATL)
YEARJULAUGSEPOCTNOVDECJANFEBMARAPRMAYJUNTOTAL
1972-730.00.00.00.00.00.01.0T0.00.00.00.01.0
1973-740.00.00.00.00.0T0.0TT0.00.00.0T
1974-750.00.00.00.00.0TTTT0.00.00.0T
1975-760.00.00.00.00.60.0TTT0.00.00.00.6
1976-770.00.00.00.00.00.01.00.00.00.00.00.01.0
1977-780.00.00.00.00.0TT0.3T0.00.00.00.3
1978-790.00.00.00.00.00.00.24.40.00.00.00.04.6
1979-800.00.00.00.00.00.0T1.72.70.00.00.04.4
1980-810.00.00.00.00.00.0TT0.00.00.00.0T
1981-820.00.00.00.00.0T7.00.70.00.00.00.07.7
1982-830.00.00.00.00.00.01.90.57.90.00.00.010.3
1983-840.00.00.00.00.0TT1.3T0.00.00.01.3
1984-850.00.00.00.00.0T0.41.50.00.00.00.01.9
1985-860.00.00.00.00.0T0.4T0.00.00.00.00.4
1986-870.00.00.00.00.00.03.6T1.2T0.00.04.8
1987-880.00.00.00.00.00.04.2T0.00.00.00.04.2
1988-890.00.00.00.00.0T0.00.70.0T0.00.00.7
1989-900.00.00.00.00.01.30.00.00.0T0.00.01.3
1990-910.00.00.00.00.00.02.1TT0.00.00.02.1
1991-920.00.00.00.00.00.05.00.0T0.00.00.05.0
1992-930.00.00.00.00.0T0.0T4.20.00.00.04.2
1993-940.00.00.0T0.02.8T0.00.00.00.00.02.8
1994-950.00.00.00.00.00.0T0.40.00.00.00.00.4
1995-960.00.00.00.00.00.01.4
1996-97
1997-98
1998-99
1999-00T
2000-010.00.00.00.0T3.00.10.00.00.00.00.03.1
2001-T0.00.00.00.00.0
POR=51 YRS0.00.00.0TT0.20.90.50.4T0.00.02.0

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