BOULDER, COLORADO

Monthly Total Heating Degree Days

(050848)

Base Temperature = 65 F

File last updated on Apr 4, 2013
*** Note *** Provisional Data *** After Year/Month 201303
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
1893 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 420.00 766.00 826.15 a 2012.15
1894 602.50 l 700.00 j 721.00 424.14 a 0.00 z 0.00 z 8.30 c 21.00 0.00 z 0.00 z 0.00 z 1039.00 2213.44
1895 1194.07 d 1127.00 b 917.71 b 406.50 267.24 b 131.00 20.50 u 0.00 z 0.00 z 0.00 z 0.00 z 0.00 z 4043.52
1896 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
1897 0.00 z 0.00 z 0.00 z 0.00 z 156.00 89.00 28.00 9.50 52.50 401.00 694.00 1072.50 2502.50
1898 1064.00 732.50 907.50 474.00 409.00 79.50 14.00 3.00 156.00 495.00 850.50 1106.50 6291.50
1899 1037.00 1315.50 948.00 478.00 251.00 75.00 16.50 4.00 75.00 458.00 519.50 903.00 6080.50
1900 868.00 936.00 678.50 575.00 184.00 21.00 14.00 2.50 164.50 246.00 616.00 809.50 5115.00
1901 887.00 997.50 776.50 540.00 a 175.00 80.50 0.00 0.00 128.50 345.00 516.72 a 931.50 5378.22
1902 1014.00 755.50 803.00 489.00 190.50 55.00 28.42 a 7.00 172.00 316.20 a 685.86 a 888.00 5404.48
1903 872.02 d 1179.50 870.14 b 497.07 a 312.58 a 174.11 b 23.00 2.50 184.00 330.00 666.00 782.00 5892.92
1904 1026.10 a 669.59 a 669.50 469.50 302.50 129.50 30.50 10.50 96.00 320.00 496.50 857.50 5077.69
1905 1098.84 c 1065.50 635.50 558.00 374.00 34.50 19.00 0.00 55.00 524.00 639.83 a 900.72 d 5904.89
1906 804.50 771.00 1092.00 443.00 239.00 119.50 39.00 13.43 a 143.00 423.50 793.00 735.00 5615.93
1907 953.50 621.50 530.00 546.00 450.00 90.00 4.50 9.50 110.50 339.00 722.22 c 665.00 g 4376.72
1908 856.00 782.50 595.00 370.00 329.00 82.00 29.00 28.00 90.50 501.00 751.00 953.00 5367.00
1909 853.50 838.50 969.00 692.00 348.50 82.00 2.50 0.00 114.00 348.00 637.00 1398.00 6283.00
1910 1064.00 975.50 338.00 321.00 307.00 42.00 0.00 z 0.00 z 96.72 a 332.50 575.50 916.05 a 4968.27
1911 820.50 956.50 600.00 468.00 235.00 16.00 17.00 20.50 84.00 537.50 841.00 0.00 z 4596.00
1912 0.00 z 0.00 z 753.50 h 548.00 252.17 e 123.89 c 16.50 5.00 312.00 466.00 643.97 a 1031.50 3399.03
1913 1069.00 1145.00 901.00 472.50 288.00 62.50 21.50 1.55 a 193.00 524.50 586.00 1184.00 6448.55
1914 855.08 a 917.78 a 543.00 f 506.90 a 246.50 28.50 4.00 4.65 a 46.50 331.50 522.00 1255.00 4718.41
1915 1079.50 803.50 1000.00 388.50 345.00 97.50 30.00 43.50 126.72 a 311.00 622.00 1005.36 b 5852.59
1916 1227.50 813.00 506.50 424.50 239.73 a 12.00 0.00 14.50 106.00 456.00 745.38 d 1192.50 5737.62
1917 1101.00 853.50 1002.85 a 590.00 454.00 80.00 0.00 0.00 38.50 466.50 512.50 804.00 5902.85
1918 1182.00 767.00 530.50 622.00 132.50 20.50 0.00 0.00 130.50 324.98 a 817.50 1001.50 5528.98
1919 887.50 944.16 c 755.50 443.50 211.00 71.00 0.00 0.00 40.00 291.00 i 585.50 j 530.50 l 3352.66
1920 914.50 908.50 805.50 760.00 296.00 93.89 c 0.00 36.17 a 140.00 c 393.38 b 868.97 a 992.00 b 6208.90
1921 951.50 773.00 603.50 568.45 a 260.83 b 54.50 3.00 1.00 61.55 a 251.50 620.69 a 899.00 5048.52
1922 1198.50 966.00 c 757.50 579.50 234.00 37.50 6.00 0.00 a 36.67 c 402.00 818.50 896.50 5932.67
1923 831.00 1012.15 a 972.00 534.00 301.00 78.00 0.00 17.05 a 166.50 665.00 697.00 1014.00 6287.70
1924 1093.00 698.50 1104.00 513.50 342.00 36.50 6.50 1.00 252.50 402.00 634.00 1248.00 6331.50
1925 1070.00 670.50 647.00 405.50 228.00 63.50 6.72 a 16.50 111.00 730.00 744.00 1006.50 5699.22
1926 1043.50 727.00 844.50 555.00 231.00 62.00 5.50 1.00 162.00 304.50 658.50 1062.50 5657.00
1927 889.50 742.50 863.00 472.50 193.50 127.50 8.00 26.00 170.00 330.00 589.14 a 1174.38 a 5586.02
1928 890.00 937.50 784.50 572.00 269.00 162.50 10.50 20.50 105.00 419.00 802.50 1037.00 6010.00
1929 1193.50 1168.50 770.50 539.50 296.00 39.50 3.50 0.00 221.50 391.00 971.00 851.50 6446.00
1930 1506.50 651.50 847.00 286.00 308.50 25.00 10.50 5.50 80.50 467.00 706.50 1009.00 5903.50
1931 919.50 743.00 861.50 505.50 317.00 18.00 2.58 a 0.00 66.00 333.50 806.50 939.50 5512.58
1932 1163.00 736.50 1001.82 a 433.00 192.50 63.00 0.00 12.50 104.00 478.50 651.72 a 1303.50 6140.04
1933 890.00 1006.00 664.00 562.50 325.00 6.00 0.00 c 18.00 46.00 216.48 a 556.00 653.50 4943.48
1934 807.00 771.50 605.50 410.00 108.50 20.00 0.00 5.00 171.50 248.50 619.00 874.50 4641.00
1935 815.00 755.50 684.00 579.00 483.00 48.00 s 0.00 5.00 128.00 425.50 850.50 968.00 5693.50
1936 1020.00 1122.00 718.50 448.00 175.00 59.50 0.00 10.00 118.50 492.50 0.00 z 924.00 5088.00
1937 1456.00 905.00 840.50 515.00 221.00 140.00 0.00 3.50 71.50 367.50 739.50 1005.00 6264.50
1938 969.00 821.50 724.00 495.00 365.00 48.50 3.50 4.00 70.50 346.50 883.50 1015.00 5746.00
1939 944.00 1095.50 732.00 491.00 185.00 44.50 0.00 47.50 108.50 422.00 708.00 798.00 5576.00
1940 1288.50 886.00 694.50 585.00 242.00 55.00 14.50 19.50 151.00 377.00 909.00 1019.00 6241.00
1941 1007.00 856.59 a 952.73 a 670.50 247.50 139.50 15.50 35.65 a 251.00 538.50 685.50 963.50 6363.48
1942 1131.50 1152.00 901.50 475.50 343.00 70.34 a 3.00 6.50 180.50 480.50 669.50 868.50 6282.34
1943 968.00 708.00 912.50 320.50 393.50 93.50 0.00 0.00 132.00 380.50 693.00 960.50 5562.00
1944 1031.50 963.50 986.50 687.00 271.50 91.50 10.50 18.00 128.50 362.00 700.50 1006.00 6257.00
1945 975.50 885.50 757.00 710.50 282.00 175.00 11.50 10.50 249.50 329.00 667.50 1046.50 6100.00
1946 994.00 774.00 610.00 300.50 427.50 75.50 0.00 3.44 d 145.00 533.00 842.50 816.50 5521.94
1947 1010.71 b 944.50 884.00 556.00 328.50 122.50 0.00 g 3.00 46.00 260.50 902.00 866.50 5924.21
1948 1036.50 982.00 921.50 356.50 196.00 34.00 0.00 a 3.00 0.00 z 0.00 z 0.00 z 348.50 v 3529.50
1949 1336.50 866.50 709.50 360.00 163.27 a 61.00 0.00 0.00 44.50 425.00 358.00 868.00 5192.27
1950 994.00 640.00 738.00 460.00 314.00 41.00 0.00 2.00 151.00 140.00 675.50 769.00 4924.50
1951 1038.50 758.50 855.00 550.00 204.00 135.50 17.50 11.50 115.50 421.00 731.50 1031.00 5869.50
1952 901.50 780.50 891.50 423.50 212.50 0.50 16.00 0.52 a 37.00 246.50 835.00 886.50 5231.52
1953 667.50 790.00 585.00 599.50 310.50 22.00 1.00 0.00 23.50 257.50 566.50 915.50 4738.50
1954 782.50 487.50 862.50 277.00 241.00 32.00 0.00 0.00 48.50 366.46 c 524.50 784.50 4406.46
1955 1054.50 984.00 826.00 369.50 160.68 a 96.00 0.00 0.00 106.50 258.50 783.50 871.50 5510.68
1956 858.00 990.50 690.50 474.50 129.50 0.00 1.50 15.50 36.00 227.50 711.50 782.00 4917.00
1957 1159.50 641.50 754.00 641.00 312.00 52.50 0.00 0.00 122.50 360.00 743.00 648.00 5434.00
1958 868.50 709.00 978.00 561.00 95.00 21.00 6.00 4.50 91.00 300.00 674.00 858.50 5166.50
1959 1006.00 935.00 761.50 545.50 251.50 16.00 0.00 0.00 203.50 477.00 733.00 805.50 5734.50
1960 1045.00 1062.00 767.00 386.50 196.50 13.00 3.00 9.50 69.00 334.00 635.50 916.00 5437.00
1961 871.50 702.50 775.50 506.00 223.00 59.00 5.00 0.00 258.50 381.00 812.50 1076.50 5671.00
1962 1232.00 848.50 865.50 377.00 150.50 62.00 0.00 12.00 97.50 242.50 575.50 842.00 5305.00
1963 1289.00 676.00 740.00 395.50 108.00 35.00 0.00 a 2.50 14.50 196.00 627.50 983.50 5067.50
1964 917.00 957.50 892.50 488.50 204.00 60.00 0.00 10.50 97.50 294.50 695.50 889.00 5506.50
1965 826.00 904.50 1060.50 396.00 223.50 39.50 3.50 10.50 292.50 240.00 578.50 821.50 5396.50
1966 1041.50 944.50 582.50 497.50 128.00 58.00 0.00 7.00 75.00 356.50 656.50 958.00 5305.00
1967 881.50 759.00 578.50 422.50 332.50 114.00 0.00 17.00 89.00 311.50 706.50 1142.00 5354.00
1968 972.00 824.50 634.50 577.50 301.00 26.00 10.00 12.00 106.50 311.00 796.50 1002.50 5574.00
1969 891.50 794.50 939.50 333.00 163.00 150.50 1.00 0.00 35.50 720.00 697.50 888.50 5614.50
1970 965.00 675.00 876.00 597.50 158.00 76.00 0.00 0.00 184.50 540.00 703.50 910.50 5686.00
1971 937.00 900.50 768.50 513.50 326.00 30.00 9.00 0.00 248.00 443.00 715.00 997.50 5888.00
1972 1004.00 720.00 543.00 463.00 255.00 7.50 33.50 28.00 121.00 419.00 932.50 1150.50 5677.00
1973 1111.00 846.00 810.00 657.00 296.00 49.00 30.00 0.50 181.50 314.50 764.00 923.50 5983.00
1974 1128.00 775.00 653.50 523.00 145.00 67.50 0.00 15.00 186.50 337.00 754.50 1001.50 5586.50
1975 992.00 901.50 799.00 615.00 321.00 93.50 0.50 8.50 174.50 312.50 772.50 836.00 5826.50
1976 1008.50 685.00 823.50 474.00 274.50 44.00 0.00 2.50 173.50 485.50 770.00 880.50 5621.50
1977 1143.50 729.50 791.50 465.50 173.50 0.50 0.00 14.50 49.50 347.50 703.50 836.00 5255.00
1978 1173.00 987.00 673.50 474.00 291.92 a 93.50 0.00 5.50 89.00 340.50 744.50 0.00 z 4872.42
1979 1314.00 815.92 c 696.00 449.50 0.00 z 0.00 z 0.00 45.98 a 0.00 z 286.75 a 898.00 808.50 5314.65
1980 1102.00 827.00 810.00 521.00 293.50 9.00 0.00 z 1.50 64.00 389.50 637.00 649.50 5304.00
1981 808.50 720.50 708.00 259.00 314.50 29.00 4.00 15.00 39.50 444.50 571.03 a 872.50 4786.03
1982 970.00 827.50 655.50 447.00 285.00 111.50 3.00 0.00 152.00 452.00 0.00 z 916.50 4820.00
1983 0.00 z 400.50 k 817.00 647.00 385.00 124.00 3.50 0.00 84.50 352.88 a 734.00 1374.50 4522.38
1984 1091.50 847.50 772.00 637.50 174.00 62.50 0.00 1.00 176.50 597.27 a 725.50 964.00 6049.27
1985 1186.50 994.00 726.50 393.00 182.00 41.00 0.00 0.00 a 243.21 b 410.23 a 1017.00 1029.50 6222.95
1986 716.74 b 769.00 504.50 430.50 254.50 18.50 1.50 0.00 180.50 457.50 731.00 976.50 5040.74
1987 953.50 785.00 782.00 380.00 197.00 11.50 8.00 34.50 127.00 380.00 720.50 1060.00 5439.00
1988 1118.50 848.50 748.50 403.50 208.00 15.00 1.00 4.00 128.50 318.00 702.50 1000.00 5496.00
1989 885.00 1146.50 623.50 432.50 212.00 94.00 1.00 0.00 z 0.00 z 0.00 z 0.00 z 0.00 z 3394.50
1990 0.00 z 0.00 z 0.00 z 510.50 328.00 23.00 34.50 14.50 83.50 352.50 595.50 1165.00 3107.00
1991 1088.00 676.00 689.50 518.50 217.50 47.00 17.50 7.50 126.00 418.50 847.00 919.50 5572.50
1992 902.00 708.00 672.50 329.00 197.50 95.00 21.50 58.50 73.50 345.50 927.00 1110.50 5440.50
1993 1136.50 963.50 702.50 523.00 236.50 94.00 5.00 0.00 z 209.50 512.00 881.50 918.00 6182.00
1994 914.00 926.50 656.50 522.50 150.00 11.00 5.00 0.50 81.50 443.82 a 849.00 896.50 5456.82
1995 957.00 745.00 709.50 596.50 438.50 123.50 18.00 1.00 205.00 421.00 603.00 891.50 5709.50
1996 1094.00 792.50 838.00 441.00 226.50 31.00 0.00 4.00 172.00 380.00 732.50 884.50 5596.00
1997 1046.50 904.50 604.00 665.50 241.00 46.00 4.00 20.00 97.50 392.50 0.00 z 0.00 z 4021.50
1998 883.50 801.00 817.00 555.00 205.00 142.50 2.00 0.00 z 46.50 455.00 0.00 z 0.00 z 3907.50
1999 0.00 z 0.00 z 0.00 z 0.00 z 292.00 74.50 0.00 6.50 210.00 422.63 a 513.62 a 870.50 2389.75
2000 889.50 694.00 686.50 418.39 b 177.50 66.21 a 0.00 2.00 144.50 488.50 1010.50 1047.00 5624.60
2001 994.00 915.00 751.50 429.50 226.00 46.50 0.00 1.00 70.00 352.50 634.50 930.50 5351.00
2002 988.50 812.50 851.50 368.50 291.50 21.00 0.00 5.50 103.00 591.50 742.00 881.00 5656.50
2003 768.50 935.50 661.50 432.50 263.00 90.50 0.00 8.50 153.50 249.00 782.50 888.00 5233.00
2004 917.50 909.50 522.50 474.50 181.50 110.00 19.50 38.00 117.00 407.50 760.00 885.00 5342.50
2005 916.50 759.50 714.00 498.00 259.00 76.50 5.50 9.50 63.50 381.50 602.00 980.50 5266.00
2006 754.50 877.00 794.00 334.50 185.00 8.50 5.50 11.50 209.50 443.00 652.50 920.50 5196.00
2007 1171.00 851.50 540.50 516.50 219.00 48.00 0.00 0.00 89.50 310.00 605.00 1083.00 5434.00
2008 1034.50 838.00 745.50 516.00 255.50 47.50 0.00 31.50 134.50 409.00 569.00 1051.00 5632.00
2009 832.00 709.50 644.50 531.00 0.00 z 99.50 23.50 11.00 109.00 636.50 637.00 1188.50 5422.00
2010 991.50 974.00 692.00 487.50 362.00 45.50 7.50 0.00 33.00 312.50 757.00 862.00 5524.50
2011 990.50 926.00 613.50 484.14 a 359.50 28.50 0.00 0.00 99.00 379.00 680.50 1019.00 5579.64
2012 811.00 951.00 439.00 327.50 176.00 3.50 0.00 0.50 64.00 444.00 561.21 a 971.00 4748.71
2013 992.00 923.48 a 754.85 a 18.50 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 2670.33
Period of Record Statistics
MEAN 1001.22 856.49 757.62 487.40 255.83 63.34 6.98 9.32 122.16 391.29 707.93 955.46 5595.93
S.D. 148.26 141.91 141.40 98.77 79.89 41.86 9.62 11.90 63.40 104.12 117.85 136.71 437.75
SKEW 0.66 0.50 0.00 0.11 0.46 0.61 1.49 1.84 0.65 0.66 0.18 0.68 -0.12
MAX 1506.50 1315.50 1104.00 760.00 483.00 175.00 39.00 58.50 312.00 730.00 1017.00 1398.00 6448.55
MIN 667.50 487.50 338.00 259.00 95.00 0.00 0.00 0.00 14.50 140.00 358.00 648.00 4406.46
NO YRS 113 113 114 116 115 115 114 113 113 114 110 110 93