DOE/ORO/2327 Oak Ridge Reservation Annual Site Environmental ...

C-6 Appendix C. Climate Overview for the Oak Ridge Area
Table C.1. Climate normals (1980–2009) and extremes (1948–2009) for Oak Ridge, Tennessee (Town Site), with 2009 comparisons
Monthly variables January February March April May June July August September October November December Annual
Temperature, °C (°F)
30-Year Average Max 8.3 (47.0) 11.2 (52.2) 16.4 (61.5) 21.4 (70.6) 25.8 (78.5) 29.8 (85.6) 31.5 (88.7) 31.2 (88.1) 27.7 (81.9) 21.9 (71.4) 15.6 (60.1) 9.6 (49.3) 20.9 (69.6)
2009 Average Max 7.4 (45.3) 11.2 (52.1) 16.4 (61.6) 21.4 (70.6) 25.1 (77.1) 30.7 (87.2) 29.3 (84.8) 30.0 (86.0) 26.2 (79.2) 19.2 (66.6) 16.7 (62.0) 8.4 (47.2) 20.2 (68.3)
62-Year Record Max 25 (77) 26 (79) 30 (86) 33 (92) 34 (93) 38 (101) 41 (105) 39 (103) 39 (102) 32 (90) 28 (83) 26 (78) 41 (105)
30-Year Average Min -2.2 (28.1) -0.7 (30.8) 3.0 (37.4) 6.7 (44.1) 12.5 (54.5) 17.1 (62.8) 19.6 (67.3) 19.1 (66.4) 15.2 (59.4) 8.4 (47.1) 3.1 (37.5) -0.9 (30.4) 8.4 (47.2)
2009 Average Min -2.7 (27.1) 0.0 (32.0) 4.8 (40.6) 7.9 (46.3) 14.3 (57.8) 18.9 (66.1) 18.5 (65.3) 19.3 (66.8) 17.9 (64.3) 9.2 (48.5) 4.3 (39.7) 0.0 (32.0) 9.4 (48.9)
62-Year Record Min -27 (-17) -25 (-13) -17 (1) -7 (20) -1 (30) 4 (39) 9 (49) 10 (50) 1 (33) -6 (21) -18 (0) -22 (-7) -27 (-17)
30-Year Average 3.1 (37.6) 5.3 (41.5) 9.7 (49.5) 14.4 (58.0) 19.2 (66.5) 23.5 (74.3) 25.6 (78.0) 25.2 (77.3) 21.5 (70.7) 15.2 (59.3) 9.3 (48.8) 4.4 (39.9) 14.7 (58.5)
2009 Average 2.9 (37.2) 6.2 (43.1) 10.6 (51.1) 14.9 (58.8) 19.7 (67.5) 24.9 (76.9) 23.9 (75.1) 24.7 (76.4) 22.1 (71.8) 14.2 (57.6) 10.5 (50.9) 4.2 (39.6) 14.9 (58.8)
2009Dep from Average -0.2 (-0.4) 0.9 (1.6) 0.9 (1.6) 0.4 (0.8) 0.6 (1.0) 1.4 (2.6) -1.6 (-2.9) -0.5 (-0.9) 0.6 (1.1) -0.9 (-1.7) 1.2 (2.1) -0.2 (-0.3) 0.2 (0.4)
30-year average heating degree days, °C (°F) a
468 (842) 366 (659) 267 (480) 128 (231) 36 (65) 2 (3) 0 0 14 (25) 113 (204) 268 (482) 429 (773) 2091 (3763)
30-year average cooling degree days, °C (°F) a
0 0 2 (4) 15 (28) 66 (118) 161 (290) 228 (410) 215 (387) 108 (195) 18 (32) 1 (2) 0 815 (1466)
Precipitation, mm (in.)
30-Year Average 119.7 (4.71) 122.5 (4.82) 115.6 (4.55) 113.1 (4.45) 114.1 (4.49) 96.3 (3.79) 131.4 (5.17) 81.6 (3.21) 96.6 (3.80) 71.1 (2.80) 119.7 (4.71) 131.1 (5.16) 1313 (51.66)
2009 148.4 (5.48) 87.1 (3.43) 110.3 (4.34) 96.0 (3.78) 147.6 (5.81) 149.1 (5.87) 150.4 (5.92) 116.1 (4.57) 139.2 (5.48) 146.9 (5.78) 66.6 (2.62) 207.6 (8.17) 1565.4 (61.61)
2009 Dep from Average 28.7 (1.13) -35.3 (-1.39) -5.3 (-0.21) -17.0 (-0.67) 33.5 (1.32) 52.8 (2.08) 19.1 (0.75) 34.6 (1.36) 42.7 (1.68) 75.7 (2.98) -53.1 (-2.09) 76.5 (3.01) 252.8 (9.95)
62-Year Max Monthly 337.2 (13.27) 324.7 (12.78) 311.0 (12.24) 356.5 (14.03) 271.9 (10.70) 283.0 (11.14) 489.6 (19.27) 265.8 (10.46) 176.6 (6.95) 176.6 (6.95) 310.5 (12.22) 321.2 (12.64) 1939 (76.33)
62-Year Max 24-hr 108.0 (4.25) 131.6 (5.18) 120.4 (4.74) 158.5 (6.24) 112.0 (4.41) 94.0 (3.70) 124.8 (4.91) 190.1 (7.48) 129.8 (5.11) 67.6 ( 2.66) 130.1 (5.12) 130.1 (5.12) 190.1 (7.48)
62-Year Min Monthly 23.6 (0.93) 21.3 (0.84) 54.1 (2.13) 22.4 (0.88) 20.3 (0.80) 13.5 (0.53) 31.3 (1.23) 13.7 (0.54) Trace Trace 34.8 (1.37) 17.0 (0.67) 911.4 (35.87)
Snowfall, mm (in.)
30-Year Average 68.6 (2.7) 71.1 (2.8) 27.9 (1.1) 7.6 (0.3) 0 0 0 0 0 0 Trace 38.1 (1.5) 213.4 (8.4)
2009 Totals 25.4 (1.0) 25.4 (1.0) 0 Trace 0 0 0 0 0 0 0 50.8 (2.0) 101.6 (4.0)
62-Year Max Monthly 243.9 (9.6) 437.0 (17.2) 533.6 (21.0) 149.9 (5.9) Trace 0 0 0 0 Trace 165.2 (6.5) 533.6 (21.0) 1052 (41.4)
62-Year Max 24-hr 210.9 (8.3) 287.1 (11.3) 304.9 (12.0) 137.2 (5.4) Trace 0 0 0 0 Trace 165.2 (6.5) 304.9 (12.0) 304.9 (12.0)
Days w/Temp
30-Year Max ≥ 32C 0 0 0 0.2 0.8 7.7 14.7 13.3 4.2 0 0 0 40.9
2009 Max ≥ 32 C 0 0 0 0 0 7 1 7 0 0 0 0 15
30-Year Min ≤ 0C 21.5 16.7 10.9 2.8 0 0 0 0 0 1.8 10.5 18.8 83.0
2009 Min ≤ 0C 21 16 7 1 0 0 0 0 0 0 3 9 64
30-Year Max ≤ C 2.6 0.9 0.2 0 0 0 0 0 0 0 0 1.5 5.2
2009 Max ≤ 0C 2 1 0 0 0 0 0 0 0 0 0 0 3
Days w/Precip
30-Year Avg ≥ 0.01 in. 11.5 11.0 11.9 10.6 11.7 10.9 12.3 9.6 8.5 8.4 9.6 11.7 127.7
2009 Days ≥ 0.01 in. 12 10 12 12 18 12 13 12 17 14 6 11 149
30-Year Avg ≥ 1.00 in. 1.3 1.4 1.2 1.2 1.2 1.0 1.4 0.8 1.3 0.9 1.5 1.6 14.8
2009 Days ≥ 1.00 in. 1 1 1 2 1 1 1 1 1 1 1 3 15
Oak Ridge Reservation