2001 Portland, Maine (PWM)

views updated

2001 PORTLAND, MAINE (PWM)

The Portland City Airport is located 2 3/4 miles west of the site of the former city office. The surrounding country is mostly open, rolling and sloping generally toward the Fore River, a body of brackish water about 1,000 feet wide at a distance of about 1/2 mile from the station and forming one boundary (north through east) of the field. The airport is about 5 1/2 miles west–northwest of the open ocean. A slight rise reaching an elevation of 100 feet, lying northwest of the field, cuts down the wind slightly from that direction. The older portion of the city is situated on a hill rising abruptly from sea level to 170 feet, 1 1/2 miles east of the airport and on the opposite side of the Fore River. A line of low hills southeast of the airport, near the ocean, which reach a maximum height of 160 feet, shuts off sight of the ocean from the airport. Sebago Lake with an area of 44 square miles is situated about 15 miles to the northwest and 45 miles farther are the White Mountains, averaging 3,000 to 5,000 feet in height.

As a rule, Portland has very pleasant summers and falls, cold winters with frequent thaws, and disagreeable springs. Very few summer nights are too warm and humid for comfortable sleeping. Autumn has the greatest number of sunny days and the least cloudiness. Winters are quite severe, but begin late and then extend deeply into the normal springtime.

Heavy seasonal snowfalls, over 100 inches, normally occur about each 10 years. True blizzards are very rare. The White Mountains, to the northwest, keep considerable snow from reaching the Portland area and also moderate the temperature. Normal monthly precipitation is remarkably uniform throughout the year.

Winds are generally quite light with the highest velocities being confined mostly to March and November. Even in these months the occasional northeasterly gales have usually lost much of their severity before reaching the coast of Maine.

Temperatures well below zero are recorded frequently each winter. Cold waves sometimes come in on strong winds, but extremely low temperatures are generally accompanied by light winds.

The average freeze–free season at the airport station is 139 days. Mid–May is the average occurrence of the last freeze in spring, and the average occurrence of the first freeze in fall is late September. The freeze–free period is longer in the city proper, but may be even shorter at susceptible places further inland.

Daily maximum temperatures at the present airport site agree closely with those near the former intown office, but minimum temperatures on clear, quiet mornings range as much as 15 degrees lower at the airport.

NORMALS, MEANS, AND EXTREMES

PORTLAND, ME (PWM)

LATITUDE:    LONGITUDE:    ELEVATION (FT):     TIME ZONE:    WBAN: 14764

43 38′ 32″ N  70 18′ 16″ W  GRND: 69 BARO: 72  EASTERN (UTC + 5)

ELEMENTPORJANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECYEAR
TEMPERATURE FNORMAL DAILY MAXIMUM3030.333.141.452.363.272.778.877.469.358.747.035.154.9
MEAN DAILY MAXIMUM4530.733.341.452.763.573.278.777.569.558.847.435.955.2
HIGHEST DAILY MAXIMUM616464888594989910395887471103
YEAR OF OCCURRENCE195019571998195719871991197719751983196319872001AUG 1975
MEAN OF EXTREME MAXS.5449.150.659.471.783.389.292.090.286.075.864.754.572.2
NORMAL DAILY MINIMUM3011.413.524.534.143.452.158.357.148.938.330.417.835.8
MEAN DAILY MINIMUM4512.614.024.533.643.152.358.256.948.838.130.218.235.9
LOWEST DAILY MINIMUM61-26-39-2182333403323153-21-39
YEAR OF OCCURRENCE197119431950195419561944196519651941197619891963FEB 1943
MEAN OF EXTREME MINS.54–9.1–7.03.921.730.640.647.644.533.323.614.9–2.720.2
NORMAL DRY BULB3020.823.333.043.353.362.468.667.359.148.538.726.545.4
MEAN DRY BULB5421.823.932.543.153.362.768.667.058.848.638.827.345.5
MEAN WET BULB4920.422.129.538.648.357.362.961.854.845.036.025.041.8
MEAN DEW POINT4913.414.622.331.943.053.459.358.551.440.530.818.836.5
NORMAL NO. DAYS WITH:
MAXIMUM 90300.00.00.00.00.20.91.91.20.30.00.00.04.5
MAXIMUM 323017.212.94.10.10.00.00.00.00.00.01.012.447.7
MINIMUM 323029.926.525.213.52.00.00.00.00.88.619.328.9154.7
MINIMUM 0306.13.90.50.00.00.00.00.00.00.00.02.813.3
H/CNORMAL HEATING DEG. DAYS3013701168992651363100113918951278911947378
NORMAL COOLING DEG. DAYS30000002212311112000268
RHNORMAL (PERCENT)3067656667717575767774737071
HOUR 01 LST3072707277828788888883797580
HOUR 07 LST3073737372757981848584807778
HOUR 13 LST3058565654586060606058616058
HOUR 19 LST3066646666697373767875736971
SPERCENT POSSIBLE SUNSHINE5556605655546063646357485357
W/OMEAN NO. DAYS WITH:
HEAVY FOG (VISBY 1/4 MI)612.12.23.43.04.95.06.35.65.04.63.52.047.6
THUNDERSTORMS610.00.10.40.51.94.14.53.51.50.60.40.117.6
CLOUDINESSMEAN:
SUNRISE-SUNSET (OKTAS)15.66.4
MIDNIGHT-MIDNIGHT (OKTAS)
MEAN NO. DAYS WITH:
CLEAR14.02.07.07.06.01.09.03.08.05.0
PARTLY CLOUDY11.03.04.05.01.01.02.04.0
CLOUDY14.05.07.010.09.02.03.06.03.08.0
PRMEAN STATION PRESSURE(IN)2929.9329.9329.9029.8829.8929.8729.8829.9429.9729.9929.9629.9429.92
MEAN SEA-LEVEL PRES. (IN)4829.9829.9929.9629.9429.9729.9429.9629.9930.0530.0630.0030.0129.99
WINDSMEAN SPEED (MPH)419.29.410.110.19.18.47.77.78.18.58.98.88.8
PREVAIL. DIR (TENS OF DEGS)2436343218181818181834363418
MAXIMUM 2-MINUTE:
SPEED (MPH)738454140323432573337414057
DIR. (TENS OF DEGS)16081129362602282936103028
YEAR OF OCCURRENCE199619951999199519952000199919981995200019971997AUG 1998
MAXIMUM 5-SECOND:
SPEED (MPH)753565447444444614147725172
DIR. (TENS OF DEGS)16071329322625280212151715
YEAR OF OCCURRENCE199619952000199519952000199719981996199519952000NOV 1995
PRECIPITATIONNORMAL (IN)303.533.333.674.083.623.443.092.873.093.905.174.5544.34
MAXIMUM MONTHLY (IN)6111.927.109.979.909.649.017.4815.229.8116.8313.509.6916.83
YEAR OF OCCURRENCE197919811953197319841998197619911954199619831969OCT 1996
MINIMUM MONTHLY (IN)610.760.040.810.280.490.700.610.270.300.260.900.980.04
YEAR OF OCCURRENCE197019871965199919651941196519471948194719761955FEB 1987
MAXIMUM IN 24 HOURS (IN)613.563.413.475.264.665.582.687.837.4913.324.703.8213.32
YEAR OF OCCURRENCE197719811951197319891967199619911954199619901969OCT 1996
NORMAL NO. DAYS WITH:
PRECIPITATION 0.013010.59.511.411.712.011.410.19.78.99.511.812.2128.7
PRECIPITATION 1.00300.70.81.00.90.70.80.70.60.81.21.71.411.3
SNOWFALLNORMAL (IN)3019.316.511.63.40.10.00.00.0T0.43.216.470.9
MAXIMUM MONTHLY (IN)6062.461.249.015.97.00.00.00.0T3.820.554.862.4
YEAR OF OCCURRENCE197919691993198219451992196919971970JAN 1979
MAXIMUM IN 24 HOURS (IN)6027.121.518.615.97.00.00.00.0T3.611.122.827.1
YEAR OF OCCURRENCE197919691993198219451992196919721970JAN 1979
MAXIMUM SNOW DEPTH (IN)4931313317100002104040
YEAR OF OCCURRENCE19791967196719561966196919721970DEC 1970
NORMAL NO. DAYS WITH:
SNOWFALL 1.0304.43.43.10.90.*0.00.00.00.00.11.04.317.2
PRECIPITATION (inches) 2001 PORTLAND, ME (PWM)
YEARJANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECANNUAL
19722.095.146.012.533.174.242.050.804.313.927.876.4948.62
19732.582.573.339.906.284.871.703.482.233.382.409.5752.29
19743.412.073.823.824.204.693.661.455.431.744.854.4143.55
19754.402.513.203.711.094.872.063.894.344.506.018.1448.72
19764.442.842.472.423.991.537.484.871.865.370.903.2241.39
19776.463.756.923.462.043.382.832.794.638.306.466.6157.63
19786.910.874.194.464.362.421.672.360.593.232.263.1536.47
197911.923.504.176.485.151.975.905.533.286.713.952.5961.15
19800.981.364.545.781.833.341.992.143.002.994.751.1833.88
19810.937.101.443.462.274.595.442.316.144.712.804.5145.70
19825.172.533.204.542.916.752.613.351.901.933.611.1839.68
19834.593.949.756.825.981.354.312.581.353.3813.508.7866.33
19842.564.995.124.819.643.873.862.090.843.263.693.4448.17
19851.031.543.151.252.032.743.303.182.974.076.362.3934.01
19866.582.614.213.492.513.913.441.872.642.095.185.9144.44
19875.210.044.296.332.625.011.792.484.642.543.822.0140.78
19881.973.341.853.684.272.365.895.241.503.478.841.2143.62
19891.152.372.142.948.744.492.501.734.484.813.972.2341.55
19903.192.491.425.165.234.123.211.893.127.467.507.9052.69
19912.911.856.196.713.771.472.3515.225.442.834.344.0657.14
19924.803.423.932.471.153.994.062.593.112.484.392.1238.51
19932.803.846.265.691.142.892.731.214.103.744.055.4043.85
19945.341.296.712.944.871.251.732.826.600.633.676.2044.05
19954.923.552.142.363.312.603.140.472.404.787.274.3541.29
19965.303.032.686.443.724.356.190.503.5416.831.656.5360.76
19974.592.484.055.212.410.762.014.152.681.375.212.5737.49
19984.835.724.233.363.839.012.924.033.0010.451.801.5954.77
19996.023.874.520.284.980.951.621.538.793.892.252.0040.70
20003.412.883.665.443.072.064.031.812.463.174.194.4940.67
20011.332.588.011.261.145.372.051.284.141.722.202.0333.11
POR=130 YRS3.913.653.993.653.433.253.123.033.283.514.103.9542.87
AVERAGE TEMPERATURE (F) 2001 PORTLAND, ME (PWM)
YEARJANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECANNUAL
197222.221.128.940.652.659.667.565.358.745.235.024.043.4
197323.123.437.745.551.363.870.870.958.449.237.733.547.1
197423.224.533.945.150.661.368.267.958.844.739.330.245.6
197526.725.029.840.055.661.570.166.857.249.343.024.345.8
197615.728.231.545.052.365.965.965.457.343.636.119.443.9
197714.621.936.242.454.459.068.266.657.648.139.425.444.5
197821.119.230.240.652.761.068.068.657.848.236.426.144.2
197923.715.635.642.255.362.769.364.857.447.542.429.845.5
198022.720.532.044.353.761.069.671.261.545.936.221.345.0
198113.832.335.745.255.363.968.866.058.646.638.929.246.2
198215.023.332.142.054.658.369.264.459.248.141.332.045.0
198325.226.235.844.452.063.869.767.663.047.940.226.146.8
198419.832.028.243.353.063.969.669.157.849.639.231.246.4
198516.226.434.844.153.761.769.866.660.750.839.924.645.8
198625.023.434.646.553.660.966.366.257.447.936.329.645.6
198721.623.034.044.954.663.868.066.259.647.138.130.245.9
198821.625.734.243.554.763.871.171.159.446.541.026.046.6
198926.824.031.641.155.663.969.468.060.549.837.314.145.2
199030.225.734.744.651.862.470.369.859.852.441.833.748.1
199123.429.837.045.958.165.570.169.958.250.840.426.448.0
199223.925.930.941.451.963.465.866.858.947.337.628.945.2
199323.416.829.843.354.864.569.869.559.646.239.029.945.6
199414.019.633.544.552.366.072.466.458.449.541.531.545.8
199527.121.234.841.252.164.170.067.456.452.435.724.545.6
199621.423.929.842.952.563.066.467.459.846.835.134.545.3
199723.428.730.441.851.163.369.067.358.747.036.229.545.5
199827.131.336.745.856.860.769.569.561.249.239.432.548.3
199922.329.035.644.954.566.371.367.763.346.642.031.948.0
200021.526.437.843.353.263.767.167.359.948.940.424.646.2
200120.624.330.643.354.967.266.569.461.050.241.434.847.0
POR=127 YRS22.223.632.442.953.362.468.366.759.449.338.627.145.5

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 PORTLAND, ME (PWM)
YEARJULAUGSEPOCTNOVDECJANFEBMARAPRMAYJUNTOTAL
1972–732753190607893126412921157842575419997418
1973–7409231480813970129011269585954441317047
1974–75151720662476210711177111210867462861467248
1975–7613592304806531258152210611030594389947383
1976–7745732296608581404155911998886743541848127
1977–78295423351876112191353127610717243771347749
1978–793932230513852120112721380905677311977509
1979–80218224053967210831305128410186133461637366
1980–8116616358485513491578910901588312547316
1981–82164518956677811021543116110146843201987616
1982–8320781855197041015122510808956123931016827
1983–848381395277381198139794911326423681107246
1984–8511132234697671043150610769306203471157120
1985–864321574337471245123611619355483541386990
1986–874752242523855109213361172955597343777291
1987–8820581715487981070133911309506413231127160
1988–8913321805697131201117411411028708286917136
1989–906251674648241573107110939356074021077274
1990–9112241703886909641283979861568236766251
1991–9211162284337301191126711271051700414847252
1992–9347302085438141112128013441084645311817499
1993–94155192575774108015771266968609389617511
1994–95135201472697102811671216929706391856928
1995–969352653808731248134311811083659384907550
1996–9723171795568899401284101110656894241357212
1997–981121192554857109311649388725692641436678
1998–9939124482761100213141002903599322616582
1999–006231055636861020134111138386453611126813
2000–0111181844917291247137111341060643330577275
2001–3215140456702928
COOLING DEGREE DAYS (base 65 F) 2001 PORTLAND, ME (PWM)
YEARJANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECANNUAL
1972000003114718000196
1973000017118920140000502
1974000242612111528000296
197500001491791202000351
19760000212880935000308
19770001321213510919000308
1978000062213815020000336
1979000015341628319300316
1980000015016320567000486
198100002030138845000277
19820000641586617000251
1983000007316112584300446
1984000008416214712000405
198500005251619235100319
19860000823939619000239
19870000284712110317000316
19880000118520922717200551
1989000026715112638000384
1990000003418117919700420
19910000299617817631000510
199200001343769330000255
1993000017217015037000430
1994000011012378910000438
1995000036717411814000376
19960000538759929000246
199700000901451008200345
19980020152115215417000361
19990000410920811659000496
20000000176819737100293
20010000231278516125300424
SNOWFALL (inches) 2001 PORTLAND, ME (PWM)
YEARJULAUGSEPOCTNOVDECJANFEBMARAPRMAYJUNTOTAL
1972–730.00.00.0T15.635.19.66.60.52.30.00.069.7
1973–740.00.00.00.00.07.215.04.36.28.30.00.041.0
1974–750.00.00.0T3.28.215.411.66.31.70.00.046.4
1975–760.00.00.0T3.625.318.14.922.2T0.00.074.1
1976–770.00.00.00.01.523.335.27.919.31.4T0.088.6
1977–780.00.00.00.01.923.130.78.212.50.80.00.077.2
1978–790.00.00.00.03.618.962.44.5T2.90.00.092.3
1979–800.00.00.01.7T1.86.011.26.80.00.00.027.5
1980–810.00.00.00.08.913.09.24.63.1T0.00.038.8
1981–820.00.00.00.0T24.025.911.08.515.90.00.085.3
1982–830.00.00.00.00.65.712.424.52.1T0.00.045.3
1983–840.00.00.00.0T12.628.33.326.4T0.00.070.6
1984–850.00.00.00.0T17.012.17.213.12.40.00.051.8
1985–860.00.00.00.03.111.218.612.06.4T0.00.051.3
1986–870.00.00.00.05.24.050.70.814.33.40.00.078.4
1987–880.00.0T0.05.49.119.820.83.04.20.00.062.3
1988–890.00.00.0TT3.54.013.88.90.70.00.030.9
1989–900.00.00.00.05.015.620.425.63.2T0.00.069.8
1990–910.00.0T0.00.26.813.46.35.7T0.00.032.4
1991–920.00.00.00.0T22.52.410.313.410.00.00.058.6
1992–930.00.0TT2.82.117.133.549.011.10.00.0115.6
1993–940.00.00.00.2T12.339.312.212.2T0.00.076.2
1994–950.00.015.517.31.40.00.00.0
1995–960.00.00.00.02.037.337.113.125.08.5
1996–971.4
1997–9820.56.317.10.99.70.00.00.0
1998–990.00.00.00.0T11.719.25.117.50.00.00.053.5
1999–000.00.00.00.0TT14.914.611.6T0.00.041.1
2000–010.00.00.0TT18.815.524.240.50.30.00.099.3
2001–0.00.00.0TT5.0
POR=60 YRS0.00.0T0.23.014.319.416.813.52.90.20.070.3

More From encyclopedia.com

About this article

2001 Portland, Maine (PWM)

Updated About encyclopedia.com content Print Article

You Might Also Like

    NEARBY TERMS

    2001 Portland, Maine (PWM)