PETALUMA AP, CALIFORNIA

Period of Record General Climate Summary - Growing Degree Days

Station:(046826) PETALUMA FIRE STN 3
From Year=1893 To Year=2012
Growing Degree Days for Selected Base Temperature (F)
Base Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. Annual
40 M 229 304 401 467 599 719 823 824 780 663 406 247 6462
40 S 229 534 935 1402 2001 2720 3542 4366 5146 5809 6215 6462 6462
45 M 102 170 248 317 444 569 668 669 630 508 259 117 4701
45 S 102 273 521 838 1282 1851 2518 3187 3817 4325 4584 4701 4701
50 M 28 65 115 175 290 419 513 514 480 354 128 37 3117
50 S 28 94 208 383 673 1091 1604 2118 2598 2952 3080 3117 3117
55 M 5 13 32 66 146 270 358 359 330 204 42 6 1832
55 S 5 18 50 117 263 533 890 1249 1580 1784 1826 1832 1832
60 M 1 1 4 17 50 131 204 206 185 83 7 0 889
60 S 1 2 6 23 74 205 409 614 799 882 889 889 889
Corn Growing Degree Days
50 M 113 162 225 271 350 430 505 506 475 408 243 125 3813
50 S 113 276 501 771 1121 1551 2056 2563 3037 3445 3688 3813 3813
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 Oct 31, 2012
Months with 5 or more missing days are not considered
Years with 1 or more missing months are not considered

Western Regional Climate Center, wrcc@dri.edu