| Monthly Heating Degree Day Records | |||||||||||||
| The following table lists the monthly heating degree Day's at Brookhaven National Laboratory since 1949. | |||||||||||||
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Total |
| 1949 | 862.0 | 820.0 | 823.0 | 472.0 | 246.0 | 62.0 | 4.0 | 13.0 | 148.0 | 263.0 | 697.0 | 953.0 | 5363.0 |
| 1950 | 839.0 | 1012.0 | 988.0 | 648.0 | 358.0 | 95.0 | 11.0 | 29.0 | 195.0 | 349.0 | 647.0 | 1024.0 | 6195.0 |
| 1951 | 1014.0 | 929.0 | 845.0 | 524.0 | 259.0 | 99.0 | 6.0 | 27.0 | 129.0 | 370.0 | 726.0 | 927.0 | 5855.0 |
| 1952 | 1012.0 | 959.0 | 875.0 | 486.0 | 310.0 | 33.0 | 4.0 | 25.0 | 144.0 | 480.0 | 662.0 | 933.0 | 5923.0 |
| 1953 | 985.0 | 840.0 | 804.0 | 537.0 | 219.0 | 111.0 | 24.0 | 52.0 | 152.0 | 383.0 | 654.0 | 854.0 | 5615.0 |
| 1954 | 1194.0 | 850.0 | 859.0 | 526.0 | 351.0 | 61.0 | 16.0 | 23.0 | 149.0 | 348.0 | 738.0 | 1024.0 | 6139.0 |
| 1955 | 1148.0 | 979.0 | 863.0 | 492.0 | 230.0 | 98.0 | 2.0 | 37.0 | 160.0 | 332.0 | 748.0 | 1250.0 | 6339.0 |
| 1956 | 1146.0 | 940.0 | 985.0 | 688.0 | 398.0 | 92.0 | 30.0 | 44.0 | 221.0 | 438.0 | 695.0 | 894.0 | 6571.0 |
| 1957 | 1282.0 | 880.0 | 828.0 | 504.0 | 284.0 | 54.0 | 10.0 | 54.0 | 136.0 | 414.0 | 592.0 | 873.0 | 5911.0 |
| 1958 | 1092.0 | 1106.0 | 858.0 | 548.0 | 366.0 | 148.0 | 16.0 | 26.0 | 132.0 | 461.0 | 678.0 | 1263.0 | 6694.0 |
| 1959 | 1156.0 | 1046.0 | 907.0 | 536.0 | 258.0 | 120.0 | 6.0 | 18.0 | 130.0 | 371.0 | 670.0 | 938.0 | 6156.0 |
| 1960 | 1068.0 | 876.0 | 1056.0 | 527.0 | 239.0 | 60.0 | 4.0 | 22.0 | 176.0 | 464.0 | 620.0 | 1168.0 | 6280.0 |
| 1961 | 1292.0 | 995.0 | 884.0 | 608.0 | 338.0 | 60.0 | 7.0 | 26.0 | 68.0 | 236.0 | 668.0 | 1006.0 | 6188.0 |
| 1962 | 1091.0 | 981.0 | 862.0 | 578.0 | 307.0 | 62.0 | 44.0 | 44.0 | 218.0 | 448.0 | 773.0 | 1142.0 | 6550.0 |
| 1963 | 1147.0 | 1096.0 | 808.0 | 538.0 | 314.0 | 56.0 | 27.0 | 34.0 | 190.0 | 292.0 | 557.0 | 1168.0 | 6227.0 |
| 1964 | 1079.0 | 1090.0 | 840.0 | 636.0 | 222.0 | 77.0 | 10.0 | 74.0 | 158.0 | 442.0 | 666.0 | 930.0 | 6224.0 |
| 1965 | 1224.0 | 1006.0 | 907.0 | 636.0 | 216.0 | 98.0 | 20.0 | 40.0 | 142.0 | 439.0 | 729.0 | 954.0 | 6411.0 |
| 1966 | 1152.0 | 977.0 | 846.0 | 696.0 | 378.0 | 64.0 | 6.0 | 8.0 | 152.0 | 509.0 | 652.0 | 1048.0 | 6488.0 |
| 1967 | 994.0 | 1118.0 | 1020.0 | 624.0 | 460.0 | 60.0 | 7.0 | 18.0 | 174.0 | 478.0 | 800.0 | 1000.0 | 6753.0 |
| 1968 | 1264.0 | 1166.0 | 848.0 | 550.0 | 356.0 | 84.0 | 13.0 | 50.0 | 80.0 | 318.0 | 688.0 | 1092.0 | 6509.0 |
| 1969 | 1150.0 | 992.0 | 960.0 | 536.0 | 316.0 | 97.0 | 24.0 | 15.0 | 164.0 | 419.0 | 722.0 | 1058.0 | 6453.0 |
| 1970 | 1342.0 | 1016.0 | 944.0 | 560.0 | 250.0 | 49.0 | 0.0 | 4.0 | 115.0 | 360.0 | 616.0 | 1013.0 | 6269.0 |
| 1971 | 1260.0 | 956.0 | 868.0 | 660.0 | 342.0 | 68.0 | 15.0 | 36.0 | 74.0 | 214.0 | 714.0 | 866.0 | 6073.0 |
| 1972 | 1004.0 | 1058.0 | 899.0 | 661.0 | 262.0 | 68.0 | 8.0 | 43.0 | 89.0 | 549.0 | 775.0 | 916.0 | 6332.0 |
| 1973 | 1042.0 | 967.0 | 686.0 | 478.0 | 312.0 | 30.0 | 7.0 | 2.0 | 168.0 | 396.0 | 634.0 | 870.0 | 5592.0 |
| 1974 | 1014.0 | 1050.0 | 792.0 | 472.0 | 318.0 | 74.0 | 16.0 | 5.0 | 124.0 | 530.0 | 650.0 | 931.0 | 5976.0 |
| 1975 | 958.0 | 966.0 | 920.0 | 634.0 | 216.0 | 56.0 | 3.0 | 12.0 | 146.0 | 336.0 | 518.0 | 988.0 | 5753.0 |
| 1976 | 1283.0 | 873.0 | 822.0 | 472.0 | 286.0 | 72.0 | 4.0 | 19.0 | 146.0 | 486.0 | 820.0 | 1192.0 | 6475.0 |
| 1977 | 1414.0 | 996.0 | 716.0 | 540.0 | 231.0 | 87.0 | 12.0 | 27.0 | 96.0 | 448.0 | 638.0 | 1024.0 | 6229.0 |
| 1978 | 1207.0 | 1200.0 | 944.0 | 570.0 | 276.0 | 94.0 | 34.0 | 7.0 | 220.0 | 494.0 | 674.0 | 945.0 | 6665.0 |
| 1979 | 1108.0 | 1252.0 | 721.0 | 588.0 | 192.0 | 107.0 | 22.0 | 26.0 | 147.0 | 392.0 | 539.0 | 840.0 | 5934.0 |
| 1980 | 1089.0 | 1116.0 | 926.0 | 532.0 | 198.0 | 106.0 | 1.0 | 0.0 | 92.0 | 384.0 | 738.0 | 1114.0 | 6296.0 |
| 1981 | 1409.0 | 906.0 | 897.0 | 485.0 | 235.0 | 28.0 | 0.0 | 10.0 | 101.0 | 483.0 | 638.0 | 994.0 | 6186.0 |
| 1982 | 1323.0 | 950.0 | 902.0 | 601.0 | 206.0 | 102.0 | 13.0 | 26.0 | 147.0 | 410.0 | 562.0 | 799.0 | 6041.0 |
| 1983 | 1024.0 | 919.0 | 743.0 | 521.0 | 334.0 | 48.0 | 2.0 | 14.0 | 124.0 | 385.0 | 602.0 | 1038.0 | 5754.0 |
| 1984 | 1247.0 | 809.0 | 983.0 | 536.0 | 309.0 | 62.0 | 7.0 | 3.0 | 185.0 | 301.0 | 664.0 | 803.0 | 5909.0 |
| 1985 | 1258.0 | 945.0 | 760.0 | 457.0 | 268.0 | 94.0 | 5.0 | 14.0 | 141.0 | 374.0 | 551.0 | 1074.0 | 5941.0 |
| 1986 | 1084.0 | 1031.0 | 808.0 | 528.0 | 229.0 | 76.0 | 16.0 | 44.0 | 147.0 | 395.0 | 710.0 | 918.0 | 5986.0 |
| 1987 | 1108.0 | 1000.0 | 780.0 | 468.0 | 269.0 | 34.0 | 6.0 | 43.0 | 103.0 | 495.0 | 628.0 | 941.0 | 5875.0 |
| 1988 | 1258.0 | 995.0 | 847.0 | 582.0 | 249.0 | 90.0 | 10.0 | 21.0 | 141.0 | 537.0 | 639.0 | 1035.0 | 6404.0 |
| 1989 | 1000.0 | 976.0 | 863.0 | 576.0 | 235.0 | 18.0 | 0.0 | 18.0 | 127.0 | 357.0 | 688.0 | 1273.0 | 6131.0 |
| 1990 | 860.0 | 835.0 | 777.0 | 545.0 | 288.0 | 43.0 | 9.0 | 4.0 | 134.0 | 279.0 | 581.0 | 794.0 | 5149.0 |
| 1991 | 1055.0 | 826.0 | 720.0 | 427.0 | 168.0 | 29.0 | 3.0 | 3.0 | 152.0 | 329.0 | 609.0 | 877.0 | 5198.0 |
| 1992 | 1051.0 | 932.0 | 897.0 | 600.0 | 296.0 | 52.0 | 18.4 | 18.6 | 121.9 | 456.0 | 671.5 | 934.8 | 6049.2 |
| 1993 | 986.0 | 1071.0 | 945.0 | 503.0 | 187.0 | 56.0 | 2.0 | 1.0 | 127.0 | 440.0 | 679.0 | 958.0 | 5955.0 |
| 1994 | 1249.0 | 1051.0 | 853.0 | 453.0 | 276.0 | 35.0 | 0.0 | 27.0 | 93.0 | 387.0 | 505.0 | 817.0 | 5746.0 |
| 1995 | 881.6 | 990.2 | 749.7 | 556.2 | 282.2 | 38.3 | 0.1 | 4.3 | 123.8 | 260.2 | 715.4 | 1083.8 | 5685.8 |
| 1996 | 1110.0 | 980.6 | 948.3 | 523.0 | 298.2 | 39.5 | 0.4 | 4.0 | 103.5 | 399.9 | 758.5 | 825.0 | 5990.9 |
| 1997 | 1090.0 | 798.6 | 846.0 | 542.0 | 320.8 | 100.3 | 5.8 | 6.3 | 107.0 | 412.2 | 711.0 | 917.0 | 5857.0 |
| 1998 | 841.3 | 776.3 | 755.8 | 495.3 | 173.5 | 79.5 | 1.8 | 3.3 | 66.3 | 343.5 | 628.0 | 831.8 | 4996.4 |
| 1999 | 1016.8 | 860.3 | 793.3 | 497.3 | 206.5 | 35.0 | 1.5 | 5.7 | 59.3 | 405.5 | 528.8 | 852.3 | 5262.3 |
| 2000 | 1125.8 | 902.3 | 686.0 | 545.5 | 224.0 | 58.3 | 2.8 | 13.1 | 140.0 | 365.0 | 666.0 | 1109.0 | 5837.8 |
| 2001 | 1104.5 | 913.1 | 880.5 | 472.0 | 211.0 | 23.0 | 15.3 | 2.0 | 99.3 | 345.3 | 503.0 | 758.8 | 5327.8 |
| 2001 | 1104.5 | 913.1 | 880.5 | 472.0 | 211.0 | 23.0 | 15.3 | 2.0 | 99.3 | 345.3 | 503.0 | 758.8 | 5327.8 |
| 2003 | 1203.0 | 1037.0 | 822.0 | 561.0 | 305.0 | 78.0 | 0.0 | 1.0 | 44.0 | 401.0 | 532.0 | 892.0 | 5876.0 |
| 2004 | 1285.0 | 975.0 | 774.0 | 464.0 | 154.0 | 52.0 | 1.0 | 15.0 | 41.0 | 361.0 | 608.0 | 934.0 | 5664.0 |
| 2005 | 1125.0 | 922.0 | 929.0 | 478.0 | 338.0 | 34.0 | 4.0 | 0.0 | 41.0 | 306.0 | 539.0 | 986.0 | 5702.0 |
| 2006 | 854.0 | 914.0 | 849.0 | 454.0 | 209.0 | 35.0 | 0.0 | 3.0 | 108.0 | 372.0 | 491.0 | 746.0 | 5035.0 |
| 2007 | 927.0 | 1060.4 | 837.0 | 559.0 | 211.0 | 41.0 | 2.0 | 13.0 | 66.0 | 189.0 | 679.0 | 948.0 | 5532.4 |
| 2008 | 983.0 | 900.9 | 846.0 | 439.6 | 276.1 | 16.4 | 0.0 | 2.9 | 82.8 | 408.8 | 663.9 | 676.4 | 5296.8 |
| 2009 | 1217.0 | 867.4 | 827.4 | 466.7 | 205.6 | 66.1 | 16.2 | 3.6 | 111.3 | 394.5 | 486.1 | 960.9 | 5622.8 |
| 2010 | 1112.5 | 915.6 | 643.7 | 314.8 | 156.3 | 27.4 | 1.5 | 2.5 | 45.3 | 325.6 | 621.9 | 1058.9 | 5226.0 |
| 2011 | 1202.4 | 922.7 | 797.6 | 445.9 | 175.2 | 24.2 | 0.0 | 0.0 | 44.0 | 310.6 | 483.3 | 792.6 | 5198.5 |
| 2012 | 917.4 | 819.3 | 569.9 | 435.8 | 143.3 | 49.9 | 0.2 | 1.6 | 76.7 | 265.3 | 717.1 | 787.5 | 4784.0 |
| 2013 | 1010.5 | 929.1 | 855.6 | 493.4 | 246.0 | 30.2 | 0.0 | 15.6 | 139.5 | 304.9 | 679.2 | 908.3 | 5612.3 |
| 2014 | 1193.6 | 1019.6 | 955.2 | 543.6 | 212.7 | 22.6 | 0.0 | 5.6 | 98.6 | 311.8 | 695.7 | 843.7 | 5902.7 |
| 2015 | 1194.7 | 1307.1 | 986.3 | 542.4 | 162.2 | 63.1 | 0.0 | 0.0 | 22.7 | 397.7 | 537.2 | 570.6 | 5784.0 |
| 2016 | 1044.1 | 923.0 | 664.3 | 560.3 | 272.4 | 28.7 | 0.0 | 0.5 | 73.7 | 324.0 | 589.1 | 931.3 | 5411.4 |
| 2017 | 950.5 | 801.8 | 919.3 | 413.5 | 275.6 | 70.3 | 3.9 | 15.1 | 64.4 | 211.3 | 649.4 | 1033.6 | 5408.7 |
| 2018 | 1138.1 | 760.8 | 876.2 | 635.9 | 158.8 | 69.5 | 4.3 | 1.0 | 45.0 | 369.3 | 703.2 | 900.5 | 5662.6 |
| 2019 | 1111.0 | 906.5 | 870.9 | 446.8 | 243.9 | 47.2 | 0.0 | 6.0 | 62.5 | 303.1 | 745.9 | 923.5 | 5667.3 |
| 2020 | 914.8 | 816.9 | 681.3 | 600.8 | 278.7 | 39.7 | 0.0 | 2.8 | 92.1 | 328.0 | 530.3 | 914.4 | 5199.8 |
| 2021 | 1058.4 | 966.8 | 767.6 | 484.9 | 271.0 | 40.0 | 6.9 | 0.0 | 34.2 | 177.8 | 663.3 | 750.7 | 5221.6 |
| 2022 | 1142.1 | 880.8 | 724.2 | 490.9 | 162.7 | 26.2 | 0.0 | 0.0 | 64.3 | 329.4 | 549.0 | 904.4 | 5274.0 |
| 2023 | 777.3 | 799.2 | 774.5 | 406.2 | 261.8 | 53.7 | 0.0 | 2.2 | 87.9 | 274.0 | 691.3 | 749.9 | 4878.0 |
| 2024 | 961.3 | 877.6 | 633.2 | 479.5 | 183.7 | 7.9 | 0.0 | 10.3 | 62.3 | 283.1 | 534.0 | 930.8 | 4963.7 |
| 2025 | 1122.5 | 901.5 | 670.2 | 2694.2 | |||||||||
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Total |
| Average | 1099.5 | 959.1 | 842.5 | 529.1 | 260.0 | 61.1 | 7.8 | 16.5 | 116.3 | 373.5 | 643.9 | 944.0 | 5853.4 |
| Maximum | 1414.0 | 1307.1 | 1056.0 | 696.0 | 460.0 | 148.0 | 44.0 | 74.0 | 221.0 | 549.0 | 820.0 | 1273.0 | 6753.0 |
| Minimum | 777.3 | 760.8 | 569.9 | 314.8 | 143.3 | 16.4 | 0.0 | 0.0 | 22.7 | 177.8 | 483.3 | 570.6 | 4784.0 |