LEWISTOWN FAA AP, MONTANA

Monthly Total Heating Degree Days

(244985)

Base Temperature = 65 F

File last updated on Jul 24, 2006
*** Note *** Provisional Data *** After Year/Month 200603
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
1896 1080.50 g 1043.00 1245.00 887.50 593.00 170.00 92.50 162.00 540.50 648.50 1006.50 h 870.14 b 6252.14
1897 1316.00 1146.00 1258.00 642.00 0.00 z 276.50 135.00 0.00 z 0.00 z 612.50 1188.00 1269.00 7843.00
1898 1260.50 978.00 1263.00 639.00 488.50 255.50 0.00 z 0.00 z 0.00 z 0.00 z 0.00 z 0.00 z 4884.50
1899 1074.50 f 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
1900 0.00 z 1313.93 a 931.00 562.00 310.00 97.00 97.50 137.00 400.00 646.00 1056.50 1060.50 6611.43
1901 1321.93 c 1286.50 967.50 659.00 310.50 343.00 44.00 44.00 471.00 477.00 781.00 822.00 j 6705.43
1902 468.50 o 0.00 z 394.50 725.50 0.00 z 314.50 159.00 146.00 427.00 540.50 1081.50 1344.00 5132.50
1903 1150.50 1271.41 a 1161.50 718.00 540.50 137.50 174.50 116.50 415.00 508.00 1042.50 1108.00 8343.91
1904 1251.50 1414.50 1200.00 589.50 476.00 235.50 133.00 90.50 312.00 517.00 665.50 1125.50 8010.50
1905 1454.50 1254.00 818.00 673.00 512.00 287.50 63.00 38.00 205.86 a 738.00 844.00 1100.00 7987.86
1906 1096.50 947.00 1195.50 555.00 482.50 258.10 a 40.00 104.50 227.00 552.50 750.00 g 1184.50 6643.10
1907 1723.50 965.50 975.50 818.00 562.00 265.00 104.50 170.50 353.00 475.00 871.50 1107.06 e 8391.06
1908 1104.38 c 1165.00 1089.00 612.00 496.50 281.50 16.50 143.00 223.00 723.00 832.00 1200.00 7885.88
1909 1550.00 1098.50 809.50 h 967.50 502.00 207.00 104.50 74.00 277.24 a 489.00 f 889.50 1589.00 7259.24
1910 1238.00 1380.00 666.00 441.00 487.50 204.00 57.50 181.00 342.00 482.80 d 943.50 1174.50 7597.80
1911 1452.50 1267.50 835.50 819.50 494.00 146.38 a 118.50 215.50 383.00 730.05 a 1264.00 1285.50 9011.93
1912 1449.50 1130.50 1556.89 d 624.00 0.00 z 132.50 r 189.00 176.50 545.17 a 768.50 850.34 a 1126.85 a 8417.26
1913 1595.98 a 1496.44 a 1386.73 a 650.69 a 509.90 b 127.24 a 141.57 a 107.97 b 332.07 a 831.83 a 878.28 a 1172.83 a 9231.53
1914 1180.07 a 1247.56 a 997.68 a 679.66 a 429.72 b 296.90 a 38.75 a 153.45 a 305.17 a 595.72 a 735.54 b 1515.38 a 8175.59
1915 1343.85 a 970.15 a 1037.98 a 463.45 a 519.77 a 376.03 a 181.35 a 6.00 l 432.00 g 590.55 a 1059.31 a 1172.83 a 7715.27
1916 1975.22 a 977.00 f 550.00 h 696.72 a 608.63 a 298.97 a 66.65 a 124.60 e 405.52 a 855.08 a 1063.45 a 1660.64 b 7755.47
1917 1512.80 a 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 1512.80
1918 0.00 z 1197.50 799.50 855.00 c 480.50 107.07 a 83.50 129.00 299.00 513.00 985.00 1053.50 6502.57
1919 979.00 1282.00 1162.00 585.00 384.00 109.50 26.50 21.00 273.50 937.50 1177.50 1418.00 8355.50
1920 1280.50 1149.00 1141.50 956.00 491.00 249.00 39.50 103.50 260.50 612.00 981.50 1171.50 8435.50
1921 1121.00 934.00 1020.50 740.00 466.00 116.00 70.50 48.50 463.00 453.00 977.50 1321.50 7731.50
1922 1456.00 1522.37 a 1104.00 753.00 455.50 95.00 64.50 10.50 131.50 464.50 957.50 1502.50 8516.87
1923 1177.50 1313.00 1114.00 698.00 431.50 175.00 11.50 63.50 267.00 537.50 j 0.00 z 0.00 z 5251.00
1924 0.00 z 891.00 1000.50 0.00 z 446.06 d 272.07 a 44.00 110.00 f 285.00 487.00 865.00 1583.00 5873.62
1925 1233.50 957.50 984.00 538.00 336.50 192.50 23.25 a 52.50 371.38 a 856.50 902.50 1017.50 7465.63
1926 1123.50 890.50 956.00 643.50 330.00 187.50 32.50 113.50 550.00 589.00 950.50 1247.50 7614.00
1927 1370.50 1163.50 981.50 787.50 642.00 225.00 59.50 125.50 330.50 516.15 a 1154.50 1687.50 9043.65
1928 1262.50 1211.27 a 923.00 778.00 289.50 333.00 75.50 175.50 328.00 716.00 919.00 1239.50 8250.77
1929 1840.00 1470.00 1064.69 b 812.50 533.00 244.50 63.50 22.50 495.50 613.00 1120.50 1282.50 9562.19
1930 1443.00 909.00 1121.00 497.59 a 475.50 201.00 15.50 23.50 243.50 788.00 866.50 1047.00 7631.09
1931 1035.50 826.00 980.50 627.00 380.00 111.00 64.00 61.00 282.50 493.00 1044.50 1134.00 7039.00
1932 1408.50 1089.50 1289.00 627.50 358.00 194.50 40.50 83.50 321.50 724.00 880.50 1450.00 8467.00
1933 1256.00 1325.50 912.50 765.00 468.00 64.50 22.50 120.50 322.00 572.50 810.50 1213.00 7852.50
1934 1014.00 930.00 941.50 542.00 230.00 182.00 37.00 89.00 448.50 494.00 777.00 1216.00 6901.00
1935 1347.00 890.00 1172.00 885.50 535.50 244.50 28.50 115.00 266.50 637.00 1028.50 1019.00 8169.00
1936 1392.50 1892.00 1075.50 722.00 234.50 131.00 5.00 57.00 275.50 592.00 894.00 1265.50 8536.50
1937 1933.37 a 1277.00 1077.50 641.00 318.00 194.50 15.00 75.50 233.00 507.50 984.50 1281.00 8537.87
1938 1152.50 1201.50 958.00 653.50 475.00 148.00 34.50 70.50 108.50 555.00 1048.45 a 1136.50 7541.95
1939 1132.50 1364.50 979.50 594.50 306.00 286.00 43.00 82.00 236.00 605.00 681.50 957.50 7268.00
1940 1609.00 1258.00 976.00 802.00 372.00 a 158.50 34.62 a 46.50 176.50 501.17 a 1249.00 1085.50 8268.78
1941 1153.50 1093.00 1013.50 716.38 a 362.50 230.77 d 33.77 c 75.50 450.00 669.00 848.50 1209.00 7855.42
1942 1280.00 1292.50 1134.50 390.00 j 519.00 304.00 53.00 98.00 312.50 570.00 424.00 o 0.00 z 5563.50
1943 0.00 z 0.00 z 586.00 o 537.00 540.00 318.50 79.50 96.00 286.00 521.00 852.00 1097.00 4327.00
1944 1101.00 1255.50 1303.00 686.00 383.00 327.00 109.00 141.50 309.50 399.50 979.66 a 1296.00 8290.66
1945 1227.50 1249.00 1016.00 874.50 575.00 372.00 56.00 63.50 444.50 551.50 1034.00 1392.50 8856.00
1946 1254.00 1075.50 845.00 564.50 566.50 249.00 34.50 127.50 377.00 854.00 1135.50 1219.50 8302.50
1947 1334.00 1271.00 1204.00 715.50 459.00 331.50 17.00 90.50 346.50 510.50 1157.50 1186.50 8623.50
1948 1276.00 1412.50 1256.00 705.50 452.00 249.00 113.50 65.50 262.50 563.50 1027.00 1520.50 8903.50
1949 1787.50 1428.50 1184.20 a 568.00 378.00 268.00 71.50 50.00 354.00 793.50 632.00 1443.10 b 8958.30
1950 2071.00 959.00 1250.00 828.00 581.00 313.00 127.00 133.50 410.50 569.50 1109.00 1126.00 9477.50
1951 1538.63 a 1196.00 1469.00 852.93 a 448.00 419.50 89.50 157.00 457.76 a 788.50 1053.00 1617.50 10087.32
1952 1509.50 1213.50 1269.00 573.00 431.00 192.00 103.50 87.50 194.48 a 536.00 1063.50 1133.00 8305.98
1953 1015.00 1055.50 969.00 886.50 613.50 265.00 63.00 43.40 a 243.00 446.00 730.00 1121.50 7451.40
1954 1635.50 810.00 1346.50 862.00 491.50 337.24 a 52.50 103.00 322.50 675.50 708.50 1034.00 8378.74
1955 1372.50 1329.50 1378.00 797.00 534.50 270.00 103.50 24.50 363.50 518.73 a 1371.50 1379.00 9442.23
1956 1399.00 1302.00 1090.50 795.00 410.50 124.00 58.50 126.50 273.50 587.50 918.00 1138.00 8223.00
1957 1835.50 1240.00 1051.50 778.50 418.50 220.50 19.50 89.50 310.50 777.00 1009.00 964.50 8714.50
1958 1006.50 1151.50 1193.00 725.50 229.50 304.00 162.00 34.00 312.50 513.50 999.50 1232.50 7864.00
1959 1353.50 1351.50 997.50 764.00 603.00 187.50 78.00 73.00 396.50 702.50 1164.00 1026.50 8697.50
1960 1422.50 1312.50 1105.00 755.00 481.00 222.50 28.00 118.00 277.50 562.50 948.50 1134.00 8367.00
1961 1109.50 858.00 884.50 828.50 426.50 51.50 20.00 15.50 526.50 667.00 1060.50 1370.00 7818.00
1962 1464.00 1230.50 1222.00 585.50 492.00 201.50 113.50 130.00 374.00 543.00 858.50 1112.00 8326.50
1963 1699.00 912.00 931.00 762.50 465.00 211.50 58.00 49.50 127.00 394.50 867.00 1333.00 7810.00
1964 1252.50 1119.00 1281.00 782.50 444.50 234.50 25.00 173.00 410.00 524.00 1114.00 1567.50 8927.50
1965 1274.00 1243.00 1539.00 779.50 584.50 286.00 63.00 120.00 667.00 456.00 924.00 1175.00 9111.00
1966 1584.50 1258.00 988.00 830.50 402.00 289.00 26.00 121.00 175.50 612.50 1025.00 1221.50 8533.50
1967 1295.50 1010.00 1272.50 897.50 541.50 290.00 40.50 23.50 188.50 543.50 987.00 1406.50 8496.50
1968 1361.00 966.00 872.00 825.50 594.00 311.00 97.50 151.00 370.50 629.50 984.50 1543.00 8705.50
1969 1945.50 1320.00 1270.50 575.00 436.00 301.00 81.50 44.00 230.00 929.00 856.00 1141.00 9129.50
1970 1503.00 1006.00 1213.00 898.50 477.50 151.50 34.00 41.00 416.00 732.50 1024.00 1331.50 8828.50
1971 1540.50 1148.00 1182.50 718.50 441.00 232.50 104.50 23.00 396.50 704.00 923.00 1511.00 8925.00
1972 1621.00 1253.00 891.50 735.00 457.00 142.50 165.00 39.50 419.00 723.00 952.00 1466.00 8864.50
1973 1253.50 1023.50 891.50 811.50 419.50 210.00 54.50 31.50 302.50 545.50 1106.50 1079.00 7729.00
1974 1331.50 954.50 1026.00 587.00 576.50 138.50 36.00 178.50 356.50 513.50 845.00 1106.50 7650.00
1975 1366.50 1464.50 1301.00 1095.50 557.00 303.00 29.00 132.50 324.00 627.50 1015.00 1148.50 9364.00
1976 1241.50 1010.50 1155.00 667.00 398.00 299.00 43.50 59.50 231.50 661.50 983.50 1171.00 7921.50
1977 1476.50 978.50 1102.50 607.50 464.00 157.00 111.00 212.00 362.00 618.50 1119.00 1521.50 8730.00
1978 1689.00 1342.00 1110.50 684.50 503.00 246.50 149.00 181.50 317.00 628.50 1308.00 1628.50 9788.00
1979 1908.00 1356.50 1124.50 873.00 564.50 208.50 49.00 59.50 185.00 565.50 1068.00 1035.50 8997.50
1980 1584.00 1162.50 1092.00 530.00 379.50 225.50 38.00 174.50 285.00 626.00 857.50 1198.00 8152.50
1981 993.00 1027.00 889.50 636.50 476.00 331.00 57.50 28.00 227.50 718.50 774.00 1221.50 7380.00
1982 1706.50 1184.50 1127.00 848.50 580.50 238.00 86.00 48.50 343.00 600.50 1025.50 1149.00 8937.50
1983 980.00 820.50 853.00 704.00 521.50 228.50 81.00 10.50 422.00 532.50 937.00 1820.00 7910.50
1984 0.00 z 940.00 967.00 690.50 475.00 250.50 33.00 31.00 467.00 821.00 924.00 1591.00 7190.00
1985 1477.00 1302.50 1086.50 557.50 298.50 210.00 30.00 185.00 539.00 716.50 1628.00 1280.00 9310.50
1986 994.50 1256.00 726.50 733.00 468.50 90.50 131.50 40.00 488.50 584.00 1107.00 1063.50 7683.50
1987 1156.00 902.00 1007.00 506.00 341.50 145.50 108.50 200.50 251.00 603.00 808.50 1246.50 7276.00
1988 1413.50 1145.00 967.00 615.50 338.00 78.50 40.00 68.50 333.50 534.00 919.50 1192.00 7645.00
1989 1263.00 1553.50 1140.50 699.50 465.50 217.00 20.50 86.00 298.00 629.00 876.00 0.00 z 7248.50
1990 0.00 z 0.00 z 0.00 z 0.00 z 497.50 211.50 47.00 27.50 131.50 599.00 797.50 1462.00 3773.50
1991 1422.00 739.00 961.00 706.00 418.00 172.00 30.00 6.00 200.00 749.00 1095.00 1017.50 7515.50
1992 1036.50 864.00 784.50 617.50 360.00 162.50 177.00 167.00 348.00 576.00 1001.00 1480.50 7574.50
1993 1550.00 1384.00 956.00 692.00 345.50 292.00 269.00 203.50 413.00 647.00 1141.00 1114.00 9007.00
1994 1286.50 1391.00 878.50 674.50 376.50 194.50 87.00 50.50 197.00 695.50 1117.00 1174.50 8123.00
1995 1135.50 1045.00 1107.50 824.50 546.50 254.00 125.50 113.00 360.50 741.00 940.50 1219.00 8412.50
1996 1629.50 1163.00 1313.00 711.50 609.00 170.00 78.50 69.00 369.00 725.00 1261.61 b 1476.50 9575.61
1997 1493.00 982.00 983.00 945.50 477.00 207.50 120.00 98.50 204.50 669.00 997.50 1161.50 8339.00
1998 1358.00 903.00 1098.50 639.50 406.00 364.50 16.00 20.00 184.00 619.50 907.00 1311.00 7827.00
1999 1191.00 886.00 888.50 812.00 524.50 273.50 146.00 54.00 421.00 612.00 693.50 1029.50 7531.50
2000 1265.50 1074.50 926.50 658.50 437.10 a 267.00 30.00 58.00 305.50 674.50 29.50 z 1454.50 7151.60
2001 1167.50 1333.00 981.50 700.00 355.50 222.00 25.00 6.50 198.50 656.00 780.00 1213.00 7638.50
2002 1271.50 1107.00 1460.00 845.00 545.00 217.50 29.50 143.00 303.00 901.50 846.00 1118.50 8787.50
2003 1134.50 1235.00 1092.00 611.50 482.50 220.00 18.50 28.50 349.50 511.50 1167.50 1164.00 8015.00
2004 1448.50 1121.50 833.50 612.00 563.50 315.50 72.50 96.00 344.50 649.00 874.00 1130.50 8061.00
2005 1362.50 956.00 960.50 694.50 515.50 263.50 53.50 127.00 282.00 556.00 901.50 1335.00 8007.50
2006 926.00 1149.00 1038.00 614.50 186.50 q 44.00 w 0.00 z 0.00 z 0.00 z 0.00 z 0.00 z 0.00 z 3727.50
Period of Record Statistics
MEAN 1365.49 1156.18 1068.24 710.73 459.87 227.97 70.99 92.30 328.41 620.90 974.91 1253.96 8329.43
S.D. 245.48 197.51 184.17 120.97 90.76 75.04 48.78 54.47 104.20 115.88 159.39 187.74 661.95
SKEW 0.65 0.36 -0.04 0.30 -0.41 -0.11 1.20 0.36 0.39 0.62 0.70 0.71 0.27
MAX 2071.00 1892.00 1556.89 1095.50 642.00 419.50 269.00 215.50 667.00 937.50 1628.00 1820.00 10087.32
MIN 926.00 739.00 394.50 441.00 229.50 51.50 5.00 6.00 108.50 394.50 632.00 870.14 6901.00
NO YRS 102 105 105 106 105 107 107 104 105 105 102 103 88