SEATTLE PORTAGE BAY, WASHINGTON

Monthly Total Heating Degree Days

(457458)

Base Temperature = 65 F

File last updated on Apr 4, 2013
*** Note *** Provisional Data *** After Year/Month 199804
a = 1 day missing, b = 2 days missing, c = 3 days, ..etc..,
z = 26 or more days missing, A = Accumulations present
Long-term means based on columns; thus, the monthly row may not
sum (or average) to the long-term annual value.
Months with 5 missing days or less use mean for missing day(s)
Individual Months not used for annual or monthly statistics if more than 5 days are missing.
Individual Years not used for annual statistics if any month in that year has more than 5 days missing.
YEAR(S JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANN
1972 0.00 z 0.00 z 0.00 z 0.00 z 0.00 z 0.00 z 0.00 z 0.00 z 0.00 z 0.00 z 0.00 z 804.00 804.00
1973 791.00 568.00 566.50 435.50 243.50 152.00 46.00 105.00 122.00 378.00 649.00 644.50 4701.00
1974 798.00 603.50 607.00 455.00 348.00 130.50 63.50 31.50 57.50 337.50 513.00 640.00 4585.00
1975 723.00 642.50 643.00 530.50 287.00 170.50 28.93 a 86.50 97.50 382.00 574.00 672.50 4837.93
1976 652.50 640.00 653.00 417.50 279.00 183.00 36.00 71.50 104.50 341.50 514.00 640.50 4533.00
1977 786.50 491.00 625.00 383.00 353.00 113.00 83.50 43.50 192.50 397.00 618.00 712.00 4798.00
1978 664.00 528.00 494.50 431.50 315.00 77.00 50.50 49.50 179.50 318.50 691.50 830.00 4629.50
1979 892.50 637.50 487.00 418.00 223.50 123.50 36.00 15.50 72.50 311.00 599.50 626.50 4443.00
1980 879.50 575.00 562.50 347.50 278.00 176.00 50.50 75.00 113.50 315.00 498.50 597.50 4468.50
1981 605.50 546.50 453.00 385.00 260.50 154.50 42.50 10.00 108.50 389.00 495.50 698.50 4149.00
1982 749.00 609.50 601.50 488.50 278.00 79.00 60.00 37.50 123.50 353.00 640.00 709.00 4728.50
1983 590.50 480.50 459.00 373.50 201.50 104.50 43.50 7.50 174.00 368.00 483.00 866.50 4152.00
1984 635.00 543.00 467.50 432.50 308.00 152.50 35.00 31.00 149.00 420.50 566.50 824.50 4565.00
1985 804.00 685.00 627.00 432.50 259.50 122.50 4.00 31.50 187.00 384.00 830.00 835.00 5202.00
1986 611.00 601.00 452.00 461.50 257.00 66.00 66.50 1.50 152.00 287.00 527.50 667.00 4150.00
1987 688.00 486.50 461.00 312.00 192.00 86.00 48.00 36.50 105.00 297.50 478.00 767.50 3958.00
1988 735.00 563.00 570.00 408.50 269.00 154.00 46.50 0.00 z 166.50 290.00 558.00 700.50 4461.00
1989 718.50 794.50 640.00 340.00 277.50 95.00 55.50 30.00 85.50 362.00 517.50 650.50 4566.50
1990 667.00 663.00 530.00 363.50 260.50 129.00 19.00 8.00 72.00 405.00 508.50 0.00 z 3625.50
1991 754.00 468.50 633.50 461.50 296.00 193.00 23.00 38.00 109.50 395.00 528.50 697.50 4598.00
1992 676.50 525.00 463.50 336.50 178.50 63.00 29.50 20.50 186.50 353.50 601.00 791.00 4225.00
1993 800.50 636.50 501.00 399.00 138.50 98.00 70.50 38.50 108.50 278.00 657.50 717.00 4443.50
1994 602.50 654.50 516.50 360.00 198.50 126.50 16.50 4.00 31.00 350.50 661.50 716.50 4238.50
1995 631.88 a 543.41 a 541.00 402.00 166.50 98.00 7.50 65.00 43.00 353.50 441.00 679.00 3971.79
1996 733.00 621.00 519.50 378.00 346.50 127.00 42.50 22.00 150.50 380.50 596.00 771.00 4687.50
1997 711.50 593.50 596.00 432.00 160.50 109.50 17.50 6.50 71.00 359.50 467.50 685.50 4210.50
1998 681.50 529.00 525.00 387.00 0.00 z 0.00 z 0.00 z 0.00 z 0.00 z 0.00 z 0.00 z 0.00 z 2122.50
Period of Record Statistics
MEAN 714.69 585.75 545.98 406.62 255.02 123.34 40.90 36.08 118.50 352.28 568.60 717.76 4471.38
S.D. 82.82 74.29 68.24 50.34 59.69 36.67 19.91 27.58 46.92 39.57 87.74 73.89 303.24
SKEW 0.40 0.61 0.10 0.33 -0.23 0.17 0.05 0.86 -0.02 -0.33 1.02 0.46 0.20
MAX 892.50 794.50 653.00 530.50 353.00 193.00 83.50 105.00 192.50 420.50 830.00 866.50 5202.00
MIN 590.50 468.50 452.00 312.00 138.50 63.00 4.00 1.50 31.00 278.00 441.00 597.50 3958.00
NO YRS 26 26 26 26 25 25 25 24 25 25 25 25 23