NATIONAL ARBORETUM DC, MARYLAND

Period of Record General Climate Summary - Growing Degree Days

From Year=1948 To Year=2012
Station:(186350) NATIONAL ARBORETUM DC
Averages Daily Extremes
Growing Degree Days for Selected Base Temperature (F)
Base Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. Annual
40 M 51 71 216 474 775 1012 1182 1133 886 556 267 83 6707
40 S 51 122 338 812 1587 2599 3781 4915 5801 6357 6624 6707 6707
45 M 21 32 123 332 620 862 1027 978 736 404 159 38 5333
45 S 21 53 176 508 1128 1990 3017 3995 4732 5136 5295 5333 5333
50 M 8 12 62 209 466 712 872 823 586 266 82 15 4113
50 S 8 20 82 291 756 1469 2341 3164 3750 4016 4098 4113 4113
55 M 2 4 28 117 318 563 717 668 438 152 35 5 3045
55 S 2 6 34 150 468 1031 1748 2416 2854 3006 3040 3045 3045
60 M 0 1 10 57 190 414 562 513 296 71 11 1 2128
60 S 0 1 11 68 259 673 1235 1748 2044 2115 2127 2128 2128
Corn Growing Degree Days
50 M 31 45 132 279 483 680 812 776 581 336 154 47 4354
50 S 31 76 207 486 969 1649 2461 3237 3818 4154 4307 4354 4354
Derived form the 1948-2012 Data
M = Monthly Data
S - Running sum of monthly data.
Growing Degree Day units are computed as the difference between the daily average temperature and the base temperature. (Daily Ave. Temp. - Base Temp.) One unit is accumulated for each degree Fahrenheit the average temperature is above the base temperature. Negative numbers are discarded. Example: If the days high temperature was 95 and the low temperature was 51, the base 60 heating degree day units is ((95 + 51) / 2) - 60 = 13. This is done for each day of the month and summed.
Corn Growing Degree Day units have the limitations that the maximum daily temperatures greater than 86 F are set to 86 F and minimums less than 50 F are set to 50 F.
Table updated on May 22,
Months with 5 or more missing days are not considered
Years with 1 or more missing months are not considered

Southeast Regional Climate Center, SERCC Webmaster