YELLOWTAIL DAM, MONTANA

Monthly Total Heating Degree Days

(249240)

Base Temperature = 65 F

File last updated on Apr 4, 2013
*** Note *** Provisional Data *** After Year/Month 201304
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
1948 0.00 z 0.00 z 0.00 z 0.00 z 0.00 z 0.00 z 3.00 0.00 105.00 413.00 811.00 1327.50 2659.50
1949 1711.00 1254.00 956.50 301.00 194.50 83.00 6.50 2.58 a 178.00 594.50 445.50 1274.50 7001.58
1950 1829.50 850.50 1057.50 603.10 a 426.00 142.50 34.00 28.50 250.00 0.00 z 0.00 z 0.00 z 5221.60
1951 0.00 z 615.00 i 721.00 j 645.00 235.50 236.00 55.50 22.00 274.29 b 533.50 0.00 z 0.00 z 2001.79
1952 1296.00 969.00 1042.00 394.00 224.50 33.50 22.50 10.00 i 0.00 z 0.00 z 0.00 z 0.00 z 3981.50
1953 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 0.00 z 0.00
1954 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 0.00 z 0.00
1955 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 0.00 z 0.00
1956 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 0.00 z 0.00
1957 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 0.00 z 0.00
1958 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 0.00 z 0.00
1959 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 0.00 z 0.00
1960 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 0.00 z 0.00
1961 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 0.00 z 0.00
1962 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 898.00 898.00
1963 1486.45 a 708.50 653.50 544.50 208.00 74.00 0.50 0.50 13.45 a 249.00 662.50 1166.50 5767.40
1964 969.00 881.50 963.00 534.50 227.00 87.50 0.00 62.50 208.50 356.00 931.50 1275.50 6496.50
1965 972.00 972.50 1223.00 470.50 301.00 75.50 0.50 19.50 465.00 273.00 725.50 1009.00 6507.00
1966 1401.00 1086.50 759.50 598.50 182.50 74.50 0.00 44.50 66.50 400.00 835.50 1057.50 6506.50
1967 1000.50 805.50 925.00 601.50 351.50 159.50 2.00 1.00 85.50 329.50 812.00 1159.50 6233.00
1968 1224.50 849.00 636.50 527.50 327.00 107.50 17.50 25.50 109.00 380.00 591.50 g 1277.50 5481.50
1969 1650.00 1070.50 964.00 361.50 218.50 161.50 2.00 0.00 66.00 736.00 735.00 1070.50 7035.50
1970 1345.00 876.50 1073.50 699.00 215.00 49.50 2.00 0.00 226.00 514.00 839.00 1092.00 6931.50
1971 1273.00 949.50 827.00 515.00 233.50 48.50 14.00 1.00 221.00 506.50 760.50 1191.00 6540.50
1972 1382.50 926.00 597.00 495.00 248.50 12.00 47.00 3.50 200.50 503.00 804.00 1252.00 6471.00
1973 1143.00 893.00 756.50 610.34 a 268.50 59.00 0.00 0.00 157.50 287.50 915.50 877.00 5967.84
1974 1166.00 689.00 756.50 392.50 334.50 71.50 1.50 17.50 166.50 324.50 705.50 912.00 5537.50
1975 1112.50 1234.50 979.50 764.50 358.00 99.00 1.00 14.00 113.00 395.50 831.00 916.00 6818.50
1976 872.50 g 775.23 a 850.00 437.50 172.50 72.00 0.00 1.00 80.50 455.50 722.00 829.00 4395.23
1977 1296.00 639.00 771.00 370.50 178.50 9.50 0.50 27.00 139.00 359.50 875.00 1166.50 5832.00
1978 1503.00 1196.00 772.50 427.50 298.00 60.50 10.50 20.00 109.50 317.75 a 1066.11 c 1269.50 7050.86
1979 1588.75 c 1103.00 756.83 b 542.00 269.50 67.00 0.00 a 0.50 32.50 284.50 854.50 779.50 6278.58
1980 1327.50 917.50 879.00 335.50 174.00 48.00 0.00 4.00 81.50 423.84 b 635.50 951.50 5777.84
1981 844.00 788.50 644.91 c 323.50 228.37 a 66.50 8.00 5.00 56.00 443.50 581.50 962.00 4951.78
1982 1369.00 892.00 832.00 522.00 306.00 115.00 5.50 0.00 200.00 405.00 880.50 1006.00 6533.00
1983 855.50 659.50 670.00 560.50 318.50 56.50 3.00 0.00 188.00 341.50 740.00 1664.50 6057.50
1984 921.00 731.50 741.00 499.50 257.00 58.50 2.00 0.00 a 252.00 504.50 717.32 b 1312.16 b 5996.48
1985 1268.42 a 1049.00 850.00 303.50 124.50 80.50 1.00 24.00 222.50 375.00 1322.00 1031.55 b 6651.97
1986 737.00 1067.00 470.50 478.50 270.50 9.00 0.00 0.00 219.00 339.00 869.00 915.00 5374.50
1987 939.50 734.00 731.00 271.50 150.00 25.50 25.00 37.00 110.00 398.00 644.50 962.00 5028.00
1988 1107.50 929.00 698.50 355.00 161.00 15.00 0.00 3.00 158.00 275.00 708.50 951.50 5362.00
1989 956.35 a 1330.00 968.00 482.50 191.50 62.50 0.00 3.00 124.00 423.50 653.00 1123.00 6317.35
1990 876.00 861.00 719.50 449.00 275.50 91.50 1.50 0.00 41.00 405.50 623.50 1295.00 5639.00
1991 1248.00 627.50 769.00 539.50 235.50 7.50 0.00 0.00 102.00 506.00 837.50 876.00 5748.50
1992 774.50 660.00 523.00 380.50 140.00 37.00 29.50 73.50 105.00 371.00 730.00 1233.00 5057.00
1993 1284.50 1114.00 615.50 443.50 135.00 86.00 32.00 21.50 163.00 436.00 879.50 841.00 6051.50
1994 996.50 1030.50 612.00 450.50 93.50 41.00 0.00 11.50 48.00 459.50 842.50 952.00 5537.50
1995 952.00 805.00 859.22 a 585.50 362.50 99.00 10.50 0.00 151.50 415.00 704.50 1003.50 5948.22
1996 1348.50 900.00 1022.50 399.50 355.00 11.50 0.00 0.00 147.00 430.00 1091.50 1283.00 6988.50
1997 1320.00 802.50 692.00 621.50 191.00 11.00 26.50 14.50 61.00 380.00 774.00 980.00 5874.00
1998 1067.50 731.00 902.00 483.00 171.50 139.50 0.00 0.00 55.50 467.00 686.00 1011.50 5714.50
1999 954.00 621.00 659.00 538.85 d 251.00 68.00 6.50 0.00 156.00 330.50 477.50 771.00 4833.35
2000 1029.50 905.50 676.50 433.00 188.50 50.50 0.00 6.50 150.00 490.00 1067.00 1261.70 a 6258.70
2001 973.50 1177.00 761.50 473.00 141.50 f 80.69 a 0.00 b 0.00 a 61.61 b 449.50 b 663.21 b 810.50 f 4640.01
2002 1039.00 790.00 1131.50 620.00 334.00 48.50 0.00 7.50 114.50 646.00 655.00 960.50 6346.50
2003 924.50 993.50 921.50 366.00 281.00 72.50 0.00 7.00 138.50 305.00 954.00 957.00 5920.50
2004 1207.50 899.00 614.50 388.50 268.00 84.50 2.50 10.00 116.00 441.00 725.50 857.50 5614.50
2005 1335.50 846.50 744.50 510.00 321.00 107.00 7.50 42.50 144.00 472.00 694.00 1109.50 6334.00
2006 750.00 976.00 866.50 411.00 241.50 14.50 0.00 0.00 150.50 392.50 n 808.50 958.50 5177.00
2007 1079.00 1056.00 603.50 556.50 208.50 38.00 0.00 11.50 147.50 418.50 753.50 1115.00 5987.50
2008 1235.00 932.00 846.00 616.50 331.00 127.00 6.00 22.50 331.50 502.00 663.00 1357.50 6970.00
2009 1015.50 872.00 973.50 572.00 269.00 161.00 9.50 15.00 103.00 696.50 711.72 a 1433.00 6831.72
2010 1228.50 1084.22 a 691.50 529.00 422.00 86.50 15.00 19.50 169.50 323.50 917.00 1169.00 6655.22
2011 896.50 f 1109.65 e 911.29 b 636.11 c 430.38 a 108.75 b 0.00 a 0.00 a 112.50 b 359.48 e 792.00 982.00 5442.17
2012 1014.50 1004.64 a 539.73 c 476.11 c 339.81 e 40.56 c 0.00 11.00 64.00 466.50 810.50 1225.50 5992.85
2013 1076.50 896.00 879.00 45.00 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 2851.50
Period of Record Statistics
MEAN 1161.64 917.07 802.60 489.75 254.70 72.82 7.49 11.87 142.80 421.39 783.23 1082.93 6115.86
S.D. 247.50 168.90 163.25 107.72 79.25 46.11 12.50 16.19 80.18 102.13 151.35 186.18 591.81
SKEW 0.53 0.27 0.29 0.09 0.28 1.00 2.12 1.89 1.39 0.92 0.87 0.60 -0.25
MAX 1829.50 1330.00 1223.00 764.50 430.38 236.00 55.50 73.50 465.00 736.00 1322.00 1664.50 7050.86
MIN 737.00 621.00 470.50 271.50 93.50 7.50 0.00 0.00 13.45 249.00 445.50 771.00 4833.35
NO YRS 52 54 54 54 53 54 55 54 54 52 51 52 46