National Grid
Heating Degree Days The following table shows the heating degree days for our Gas Service Territory.

Over the years, it has been shown that the best way to estimate energy use for space heating is by using heating degree days (HDD) rather than actual temperature. The values listed in the Heating Degree Days table represent the total number of degrees needed for the month to bring the average temperature up to 65°. Although most customers maintain a temperature above 65° at their home or facility, HDD provides an indication of the differences in temperature from month to month and year to year that impact the amount of energy needed to heat your home or facility.

To calculate the HDDs, you first find the average temperature for the day (to find the average, take the high & low temperature for the day, add them together then divide by two). If the average temperature is at or above 65°F, then the HDD amount is zero. However, there may be periods within the day where energy was used to reach the minimum of 65°. If the average temperature is below 65°F, then the HDD amount equals 65 minus the average temperature. For example, if the average temperature was 55° then the HDD amount equals 10.

Heating degree days are used for tracking energy use. By studying degree-day patterns, you can evaluate the increases or decreases in your heating bills from year to year.

For more information about our cost of gas, visit Supply Costs.

HEATING DEGREE DAYS for NATIONAL GRID'S UPSTATE NY GAS SERVICE TERRITORY
* * Normal temperatures remain static until the next rate case (with exception of Feb on leap years 1,095 will change to 1,135 )
Normal* 1,284 1,095 939 528 237 53 6 18 131 447 731 1,102 6,572 5,151
* - 30 yr Ave Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. YTD Total Winter
(Nov. thru Mar.)
2014 1,370 1,202 1,163 543 187 16 4,479 (2013-14) 5,695
2013 1,181 1,070 958 556 177 54 4 7 179 367 822 1,139 6,512 (2012-13) 4,970
2012 1,087 948 580 531 116 45 0 4 132 346 816 946 5,549 (2011-12) 4,117
2011 1,368 1,130 947 495 145 29 0 7 81 402 584 920 6,105 (2010-11) 5,394
2010 1,266 1,051 746 387 191 43 4 7 111 449 734 1,215 6,202 (2009-10) 4,855
2009 1,425 1,065 889 493 236 44 11 19 151 513 644 1,149 6,637 (2008-09) 5,291
2008 1,115 1,119 990 404 301 23 2 24 124 530 786 1,127 6,543 (2007-08) 5,180
2007 1,150 1,269 1,002 627 208 41 9 24 93 265 820 1,137 6,644 (2006-07) 4,917
2006 990 1,046 908 488 238 59 0 19 141 500 617 879 5,883 (2005-06) 4,764
2005 1,397 1,067 1,040 471 319 20 2 1 64 423 650 1,171 6,624 (2004-05) 5,348
2004 1,545 1,154 839 523 170 68 6 27 86 455 726 1,118 6,715 (2003-04) 5,329
2003 1,470 1,217 955 626 287 64 0 12 95 502 706 1,086 7,018 (2002-03) 5,550
2002 1,013 930 894 529 336 62 5 16 75 523 766 1,142 6,289 (2001-02) 4,333
2001 1,227 1,064 1,070 532 214 52 22 3 143 389 567 929 6,212 (2000-01) 5,532
2000 1,365 1,062 789 611 227 80 22 30 214 467 836 1,335 7,038 (1999-2000) 4,912
1999 1,324 1,008 1,005 546 164 36 2 22 108 499 638 1,058 6,410 (1998-99) 5,019
1998 1,095 931 831 492 98 87 5 13 109 440 720 962 5,783 (1997-98) 4,793
1997 1,272 965 982 603 370 28 13 17 163 510 849 1,087 6,859 (1996-97) 5,090
1996 1,353 1,148 1,057 607 308 14 5 5 137 468 904 967 6,973 (1995-96) 5,691
1995 1,046 1,192 815 640 234 40 7 12 206 340 879 1,254 6,665 (1994-95) 4,715
1994 1,609 1,265 1,008 504 310 40 0 47 151 466 638 1,024 7,062 (1993-94) 5,824
1993 1,174 1,317 1,050 513 204 69 1 16 202 499 786 1,156 6,987 (1992-93) 5,384
1992 1,233 1,109 1,050 614 234 74 18 37 169 570 770 1,073 6,951 (1991-92) 5,227
1991 1,259 963 857 420 151 32 1 6 198 387 745 1,090 6,109 (1990-91) 4,734
1990 990 1,006 843 496 314 45 7 10 173 392 688 967 5,931 (1989-90) 5,166
1989 1,111 1,159 987 628 216 42 2 33 164 437 782 1,545 7,106 (1988-89) 5,114
1988 1,301 1,160 937 570 192 111 8 39 157 591 689 1,168 6,923 (1987-88) 5,148
1987 1,296 1,193 842 415 195 29 5 48 155 555 730 1,020 6,483 (1986-87) 5,219  
* Normals are based on a 30-year average of weather data