2001 Anchorage, Alaska (ANC)

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2001 ANCHORAGE, ALASKA (ANC)

Anchorage is in a broad valley with adjacent narrow bodies of water. Cook Inlet, including Knik Arm and Turn again Arm, lies approximately 2 miles to the west, north, and south. The terrain rises gradually to the east for about 10 miles, with marshes interspersed with glacial moraines, shallow depressions, small streams, and knolls. Beyond this area, the Chugach Mountains rise abruptly into a range oriented north–northeast to south–southwest, with average elevation 4,000 to 5,000 feet and some peaks to 8,000 or 10,000 feet. The Chugach Range acts as a barrier to the influx of warm, moist air from the Gulf of Alaska, so the average annual precipitation is only 10 to 15 percent of that at stations located on the Gulf of Alaska side of the Chugach Range. The Alaska Mountain Range lies in a long arc from southwest, through northwest, to northeast, approximately 100 miles distant from Anchorage. During the winter, this range is an effective barrier to the influx of very cold air from the north side of the range.

The four seasons are well marked in Anchorage. In the summer, high temperatures average about 60 degrees and low temperatures nearly 50 degrees. Temperatures in the 70s are considered very warm. On summer days, temperatures on the east side of Anchorage may be about 10 degrees warmer than the official airport readings. Rain increases after mid–June. About two–thirds of the days in July and August are cloudy and one–third have rain.

Autumn is brief, beginning in early September and ending in mid–October. Temperatures begin to fall in September with snow becoming more frequent in October.

Winter can be considered as mid–October to early April when streams and lakes are frozen. Temperatures steadily decrease into January when the highs are near 20 degrees and lows near 5 degrees. The coldest weather is normally in January, when very cold days have high temperatures below zero. Cold days generally have clear skies and calm wind. Mild days do occur with temperatures in the 30s. On cold winter nights, temperatures on the east side of Anchorage may be 10–20 degrees lower than airport readings on the west side. Most winter precipitation is snow, but rain may occur on a few days.

Annual snowfall varies from about 70 inches on the west side to about 90 inches on the east side of Anchorage at low elevations. Along the Chugach Mountains, snow totals increase steadily with increasing elevations and winter arrives a month earlier and stays a month longer at the 1,000 to 2,000 foot level. Most snow is light or dry, i.e., low in water content. Freezing rain is extremely rare. Fog, made of water droplets, occurs on about fifteen days. In general, ice–fog does not occur in Anchorage.

Spring begins in late April and May when days are warm and sunny, nights are cool, and precipitation is exceedingly small. Foliage turns green by late May.

The wind in Anchorage is generally light. However, on several days each winter, strong northerly winds, up to 90 mph, affect the entire Anchorage area. Also during the winter there are about eight occurrences of very strong southeast winds which affect only the east side of Anchorage and the slopes of the Chugach Mountains. These winds occur more often above the 800 feet elevation in the Chugach where winds are funneled thru creek canyons. On the east side of Anchorage, damaging winds of over 100 mph have been recorded.

The average occurrence of the first snow is mid–October, but has occurred as early as mid–September. The average date of the last snow is mid–April, but has occurred as late as early May. The growing season is about 125 days. Average occurrence of the last temperature of 32 degrees in spring is mid–May and the first in fall is mid–September. Daylight varies from about 19 hours in late June to 6 hours in late December with 12 hours of daylight occurring in late September and late March.

NORMALS, MEANS, AND EXTREMES

ANCHORAGE, AK (ANC)

LATITUDE:    LONGITUDE:    ELEVATION (FT):    TIME ZONE:    WBAN: 26451

61 10′ 30″ N  149 59′ 36″ W  GRND:  130  BARO:   133   ALASKA (UTC + 9)

ELEMENTPORJANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECYEAR
TEMPERATURE FNORMAL DAILY MAXIMUM3021.425.833.142.854.461.665.263.055.240.527.222.542.7
MEAN DAILY MAXIMUM4821.525.633.043.554.962.465.163.155.240.227.622.342.9
HIGHEST DAILY MAXIMUM4850485165778582827361534885
YEAR OF OCCURRENCE196119911984197619691969198919781957199319791999JUN 1969
MEAN OF EXTREME MAXS.4840.141.844.454.266.773.575.472.864.553.242.340.755.8
NORMAL DAILY MINIMUM308.411.518.128.638.847.251.749.541.628.715.110.029.1
MEAN DAILY MINIMUM488.311.417.528.638.947.351.549.441.228.115.89.629.0
LOWEST DAILY MINIMUM48-34-28-24–41733383119–5-21-30-34
YEAR OF OCCURRENCE197519991971198519641961196419841992195619561964JAN 1975
MEAN OF EXTREME MINS.48–13.2–8.6–.816.929.739.444.339.629.311.2–3.0–12.314.4
NORMAL DRY BULB3014.918.725.735.846.654.458.456.348.434.621.216.335.9
MEAN DRY BULB4814.918.625.436.146.954.958.456.248.234.121.615.935.9
MEAN WET BULB1816.718.024.133.041.849.554.052.445.231.120.518.233.7
MEAN DEW POINT1812.413.317.525.534.043.449.848.341.026.416.414.628.6
NORMAL NO. DAYS WITH:
MAXIMUM 70300.00.00.00.00.63.46.53.40.10.00.00.014.0
MAXIMUM 323024.819.911.52.00.00.00.00.00.04.620.824.5108.1
MINIMUM 323030.527.328.320.32.70.00.00.13.219.828.230.2190.6
MINIMUM 0309.87.22.30.00.00.00.00.00.00.13.27.229.8
H/CNORMAL HEATING DEG. DAYS301553129612188765703182052704989421314151010570
NORMAL COOLING DEG. DAYS300000000000000
RHNORMAL (PERCENT)
HOUR 03 LST3074737172727580838278797776
HOUR 09 LST3074747066646873788078787773
HOUR 15 LST3072675754505662656467747664
HOUR 21 LST3073716864596269767876787771
SPERCENT POSSIBLE SUNSHINE4034425050504642383835312640
W/OMEAN NO. DAYS WITH:
HEAVY FOG (VISBY 1/4 MI)485.74.31.60.70.30.10.20.91.32.13.54.725.4
THUNDERSTORMS480.00.00.00.00.10.10.50.20.10.00.00.01.0
CLOUDINESSMEAN:
SUNRISE–SUNSET (OKTAS)445.65.75.45.86.16.36.36.36.36.15.86.06.0
MIDNIGHT–MIDNIGHT (OKTAS)335.55.45.35.66.16.46.46.26.05.85.65.95.9
MEAN NO. DAYS WITH:
CLEAR457.16.37.75.73.92.83.23.23.65.05.55.659.6
PARTLY CLOUDY454.83.75.66.16.66.95.86.15.34.64.63.964.0
CLOUDY4519.318.117.618.320.420.221.221.120.520.619.320.9237.5
PRMEAN STATION PRESSURE(IN)2929.4829.5829.5829.6029.7129.8029.8029.7929.6029.5029.4929.4829.62
MEAN SEA–LEVEL PRES. (IN)1829.6429.7529.7329.7729.8629.9129.9729.9029.7729.6629.6329.6229.77
WINDSMEAN SPEED (MPH)486.46.97.17.38.58.47.36.96.76.86.46.27.1
PREVAIL. DIR (TENS OF DEGS)3836363616161616161636010136
MAXIMUM 2–MINUTE:
SPEED (MPH)334412933263330293329313841
DIR. (TENS OF DEGS)16150215161817041518171615
YEAR OF OCCURRENCE199920001999200119991999200120002000200020001999FEB 2000
MAXIMUM 5–SECOND:
SPEED (MPH)347584145364440384740394958
DIR. (TENS OF DEGS)16121118181715151517161612
YEAR OF OCCURRENCE199920002000200120011999199920012000200020001999FEB 2000
PRECIPITATIONNORMAL (IN)300.790.780.690.670.731.141.712.442.702.031.111.1215.91
MAXIMUM MONTHLY (IN)482.133.072.761.911.933.404.499.776.644.112.842.679.77
YEAR OF OCCURRENCE194919551979197719891962200119891990198619761955AUG 1989
MINIMUM MONTHLY (IN)480.020.07TT0.020.170.420.330.720.350.080.09T
YEAR OF OCCURRENCE198219581983196919571993197219691998196019851995MAR 1983
MAXIMUM IN 24 HOURS (IN)481.191.161.250.781.181.842.374.121.921.601.661.624.12
YEAR OF OCCURRENCE196119561986198919801962200119891961198619641955AUG 1989
NORMAL NO. DAYS WITH:
PRECIPITATION 0.01307.78.07.35.87.17.911.513.414.512.29.611.0116.0
PRECIPITATION 1.0030*0.0*0.00.00.10.10.10.2**0.00.5
SNOWFALLNORMAL (IN)308.811.09.15.80.20.00.00.00.38.010.513.967.6
MAXIMUM MONTHLY (IN)4828.652.131.027.66.10.00.0T4.628.138.841.652.1
YEAR OF OCCURRENCE2000199619791963200119971965199619941955FEB 1996
MAXIMUM IN 24 HOURS (IN)4810.513.914.59.15.00.00.0T3.514.616.417.717.7
YEAR OF OCCURRENCE1955199619591955200119971965199619641955DEC 1955
MAXIMUM SNOW DEPTH (IN)47833840906356170001105416715906
YEAR OF OCCURRENCE195619561959195519551992199119941994MAR 1959
NORMAL NO. DAYS WITH:
SNOWFALL 1.0302.83.32.71.50.00.00.00.00.22.33.54.620.9
PRECIPITATION (inches) 2001 ANCHORAGE, AK (ANC)
YEARJANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECANNUAL
19720.560.630.680.730.810.610.421.404.422.890.760.7214.63
19730.720.110.650.330.141.070.603.400.761.740.780.3810.68
19740.021.150.600.610.340.691.221.621.532.631.012.0013.42
19750.430.770.541.710.400.471.331.194.520.690.100.8913.04
19760.980.331.770.740.160.330.600.973.501.292.841.0314.54
19771.350.520.841.910.460.491.371.354.081.920.530.6915.51
19780.391.190.450.020.033.091.780.542.161.650.852.6014.75
19790.230.692.760.940.151.793.841.562.732.542.771.1521.15
19801.281.180.300.191.682.732.273.062.533.050.490.4119.17
19810.930.970.410.190.810.834.394.962.153.491.850.3621.34
19820.020.690.420.270.541.562.412.334.662.951.720.1117.68
19830.210.23T1.360.590.660.552.892.292.670.230.4812.16
19841.301.080.080.930.961.101.113.212.591.380.151.0814.97
19850.700.670.860.501.451.010.993.543.171.070.081.4715.51
19860.200.551.700.420.500.332.023.622.854.111.231.4218.95
19871.720.200.170.240.671.091.890.431.912.601.901.1213.94
19880.380.320.650.370.560.790.643.771.262.961.111.5114.32
19890.260.170.220.981.931.142.899.773.923.631.011.6327.55
19901.421.460.460.270.711.520.811.906.640.731.311.7819.01
19910.620.420.650.230.120.182.823.543.411.931.571.8217.31
19921.171.040.310.080.581.210.792.492.832.081.170.6914.44
19930.941.170.290.091.170.170.574.024.271.902.000.3016.89
19940.590.281.510.450.511.340.571.021.661.212.471.5113.12
19950.521.000.880.081.110.913.012.192.930.950.090.0913.76
19960.112.400.420.080.200.502.042.531.932.631.380.2414.46
19970.120.520.010.251.120.601.368.372.531.930.871.8019.48
19980.450.240.070.390.632.701.013.250.720.540.181.4711.65
19990.370.280.610.291.301.102.154.623.172.630.351.4318.30
20001.040.540.480.390.691.432.581.683.240.591.130.5814.37
20011.100.850.880.340.480.244.490.971.141.570.260.2012.52
POR=58 YRS0.790.790.620.510.661.091.862.632.571.710.981.0115.22
AVERAGE TEMPERATURE (F) 2001 ANCHORAGE, AK (ANC)
YEARJANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECANNUAL
19726.413.515.726.843.351.959.056.644.531.721.312.431.9
19732.913.124.235.843.651.457.853.845.732.213.618.332.7
19746.814.123.337.947.955.557.356.349.834.522.618.835.4
197511.912.922.532.946.353.058.656.649.334.614.211.633.7
197617.112.824.134.844.953.758.956.347.433.430.623.136.4
197732.032.724.735.746.957.862.660.350.738.315.311.339.0
197821.226.329.339.149.054.558.859.851.539.326.321.439.7
197922.310.631.638.850.255.960.458.852.041.133.510.038.8
198014.327.427.239.345.853.257.054.446.737.227.60.835.9
198131.524.834.436.050.753.857.454.847.936.021.815.938.8
19826.415.526.333.144.552.956.254.747.526.621.021.533.9
198316.221.428.737.448.755.958.556.145.334.424.916.737.0
198418.819.436.438.849.658.860.856.649.335.519.818.938.6
198530.313.526.728.445.151.958.555.247.630.314.027.535.8
198625.621.824.131.046.654.658.054.348.639.025.028.338.1
198722.825.326.837.947.251.957.157.348.038.926.918.238.2
198818.022.731.337.148.555.258.856.048.033.320.522.037.6
19893.517.623.639.346.355.359.459.050.634.017.224.235.8
199015.53.828.639.949.957.158.657.849.632.39.914.834.8
199115.919.623.737.746.655.757.555.551.033.025.020.536.8
199220.315.024.935.246.155.959.555.840.331.227.115.035.5
199314.521.028.840.650.756.361.158.848.838.725.224.039.0
199421.717.125.738.647.156.758.858.848.633.515.315.736.5
199515.620.718.640.448.856.059.257.953.738.121.019.037.4
19966.115.829.238.650.156.959.956.746.525.419.013.034.8
199715.930.724.638.248.056.760.858.150.429.628.016.838.2
199815.525.830.140.247.354.757.353.849.035.923.514.337.3
199911.97.224.134.545.755.358.456.948.934.019.714.934.3
200014.825.929.637.446.155.156.854.847.134.829.725.138.1
200127.523.128.837.744.858.157.758.449.230.119.610.837.2
POR=58 YRS14.218.124.835.646.554.558.256.048.034.321.715.535.6

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 ANCHORAGE, AK (ANC)
YEARJULAUGSEPOCTNOVDECJANFEBMARAPRMAYJUNTOTAL
1972–7318525260810251308162719251448125886665439911555
1973-7421634257310121532144017971416128580552627911223
1974-752352634529371263142516431454131395457535410868
1975-761922524639371517165414851511126089761533211115
1976-7718426252197210281294101789712418725542089050
1977-7875144421820148616591349107711007714913089701
1978-79186160400792115313441321151510297814542689403
1979-8013818438473593717041568108311647645923479600
1980–8124332054285511151990103211229438634383299792
1981–822303075078931290151618131382119194962535611059
1982–8326131352011841315134215071216111782150026710363
1983–8419426958594511941491142513198807784711799730
1984–8512925446490613501423107014371182109161038810304
1985–86193298516106515231155121512061260101356430710315
1986–87215325486800119411331303110411768055433869470
1987–88243232506801113614441450122110378305042859689
1988-891842705039751331132619081322127776557328610720
1989-901731814239561428125515331715112174646523710233
1990-9119122245710061648155215181265127381356327310781
1991-922262874149881193137313801444124089157926810283
1992-9316128073510391131154315631226111772543625210208
1993-94125187477808119112671334133512127855482439512
1994-951831904859681488152315261239143373449626510530
1995-961722143358261314142518271423110278345623910116
1996-971512515491220137516081516956124679652024910437
1997-981232074321090110314861530109310737395403029718
1998-992323404758951240156616381611126290859228611045
1999-002042484789531352154415481126109082157929110234
2000–01245312534931105212301154116811138126181999368
2001–220200466107213561673
COOLING DEGREE DAYS (base 65 F) 2001 ANCHORAGE, AK (ANC)
YEARJANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECANNUAL
19720000005000005
19730000000000000
19740000001000001
19750000002000002
19760000003000003
197700000083000011
19780000001700008
19790000004000004
19800000000000000
19810000000000000
19820000000000000
19830000000000000
19840000005100006
19850000000000000
19860000004000004
19870000002000002
19880000000000000
19890000005200007
19900000031200006
19910000000000000
19920000000000000
1993000000110000011
19940000000200002
19950000010000001
19960000000000000
19970000050100006
19980000000000000
19990000007000007
20000000000000000
20010000000000000
SNOWFALL (inches) 2001 ANCHORAGE, AK (ANC)
YEARJULAUGSEPOCTNOVDECJANFEBMARAPRMAYJUNTOTAL
1972-730.00.01.53.310.76.58.11.016.11.30.00.048.5
1973-740.00.00.06.610.66.70.523.38.21.90.00.057.8
1974-750.00.00.04.48.429.25.715.48.316.10.40.087.9
1975-760.00.00.0T2.011.59.71.830.75.6T0.061.3
1976-770.00.00.011.411.113.86.12.19.514.00.00.068.0
1977-780.00.01.013.212.610.67.320.89.5T0.00.075.0
1978-790.00.00.03.98.535.23.66.231.02.80.00.091.2
1979-800.00.00.04.313.716.012.018.73.40.80.00.068.9
1980–810.00.00.010.24.21.45.06.64.41.1T0.032.9
1981–820.00.01.56.320.07.60.50.65.63.50.70.046.3
1982–830.00.00.027.123.41.93.74.3T11.00.00.071.4
1983–840.00.0T23.72.110.515.018.90.29.80.00.080.2
1984–850.00.00.03.31.818.09.77.912.87.31.30.062.1
1985–860.00.00.00.81.56.15.16.121.05.40.10.046.1
1986–870.00.00.0T3.810.118.52.22.51.60.00.038.7
1987–880.00.00.0T29.226.34.79.28.52.00.00.079.9
1988-890.00.00.012.015.318.610.12.35.1T0.20.063.6
1989-900.00.00.016.310.120.027.523.04.70.8T0.0102.4
1990-910.00.00.01.616.921.47.75.412.7T0.00.065.7
1991-920.00.00.011.619.326.221.418.32.7T0.20.099.7
1992-930.00.03.013.09.112.113.718.35.70.00.00.074.9
1993-940.00.0T4.411.95.17.51.729.96.00.00.066.5
1994–950.00.00.09.138.829.012.615.316.70.00.00.0121.5
1995–960.00.00.04.00.92.52.552.16.10.90.00.069.0
1996–970.00.00.128.125.74.73.15.10.80.20.00.067.8
1997-980.0T0.011.66.426.66.83.11.22.90.0
1998-990.0T0.00.49.134.58.36.617.43.0T0.079.3
1999-000.00.00.05.78.518.628.64.67.42.80.00.076.2
2000–010.00.0T2.13.24.211.019.715.91.36.10.063.5
2001–0.00.00.020.66.67.9
POR=58 YRS0.00.00.37.310.715.310.411.59.24.91.00.070.6

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2001 Anchorage, Alaska (ANC)

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