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 1135 will change to 1095 )
Normal*	1,284	1,135	939	528	237	53	6	18	131	447	731	1,102	6,611	5,191
* - 30 yr Ave	Jan.	Feb.	Mar.	Apr.	May	Jun.	Jul.	Aug.	Sep.	Oct.	Nov.	Dec.	YTD Total	Winter (Nov. thru Mar.)
2013	1,181	1,070	958	556	177								3,941	(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