National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce
Weather observations for the past three days for
Huntsville, Madison County Executive Airport
Metric (Imperial)
Date Time (cdt) Wind (kph) Vis. (km) Weather Sky Cond. Temperature (ºC) Relative Humidity Wind Chill (°C) Heat Index (°C) Pressure Precipitation (cm)
Air Dwpt 6 hour altimeter (cm) sea level (mb) 1 hr 3 hr 6 hr
Max. Min.
12 17:15 SW 15 16.09 Fair CLR 27.2 21 69% 29 76.15 0.0
12 16:55 Calm 16.09 Fair CLR 27.7 20.7 66% 30 76.2 0.0
12 16:35 W 11 16.09 Fair CLR 27.3 20.8 68% 29 76.23 0.0
12 16:15 W 11 16.09 Fair CLR 27.3 20.4 66% 29 76.23 0.0
12 15:55 W 11 16.09 Fair CLR 27.9 20.3 63% 30 76.23 0.0
12 15:35 W 11 16.09 Fair CLR 27.9 20.7 65% 30 76.23 0.0
12 15:15 S 6 16.09 Fair CLR 28.2 20.7 64% 30 76.2 0.0
12 14:55 S 17 16.09 Fair CLR 28.2 20.1 62% 30 76.23 0.0
12 14:35 E 6 16.09 Fair CLR 27.9 20.4 64% 30 76.28 0.0
12 14:15 NE 7 16.09 Fair CLR 27.6 20.1 64% 29 76.3 0.0
12 13:55 N 7 16.09 Fair CLR 26.7 19.6 65% 28 76.33 0.0
12 13:35 NE 11 16.09 Fair CLR 26.9 19.4 64% 28 76.35 0.0
12 13:15 N 19 16.09 Fair CLR 27 19.4 63% 28 76.38 0.0
12 12:55 N 20 16.09 Mostly Cloudy SCT050 BKN055 26.5 19.7 31 22.8 66% 28 76.4 0.0
12 12:35 N 24 G 30 16.09 Mostly Cloudy BKN046 BKN055 25.2 20.1 73% 26 76.43 0.0
12 12:15 N 31 G 59 16.09 Light Rain SCT027 BKN036 OVC049 22.9 20.4 86% 76.43 0.0
12 11:55 N 50 G 59 16.09 Overcast and Windy SCT027 OVC036 25.9 19.3 67% 27 76.38 0.0
12 11:35 W 17 16.09 Mostly Cloudy BKN034 BKN042 BKN075 30.3 21.8 60% 34 76.33 0.0
12 11:15 W 19 16.09 Overcast BKN034 OVC075 30.3 21.8 60% 34 76.33 0.0
12 10:55 SW 15 16.09 Partly Cloudy SCT034 SCT085 30.5 22.2 61% 34 76.33 0.0
12 10:15 SW 13 16.09 Fair CLR 29.8 22.2 64% 33 76.33 0.0
12 09:55 SW 11 16.09 Fair CLR 29.1 22.4 67% 32 76.35 0.0
12 09:35 W 6 16.09 Fair CLR 28.8 21.8 66% 32 76.35 0.0
12 09:15 SW 11 16.09 Fair CLR 28.2 21.6 67% 31 76.35 0.0
12 08:55 SW 15 16.09 Fair CLR 27.7 21.8 70% 30 76.33 0.0
12 08:35 SW 11 16.09 Fair CLR 27.2 22.3 75% 30 76.33 0.0
12 08:15 S 11 16.09 Fair CLR 26.5 22.4 78% 29 76.3 0.0
12 07:55 S 7 16.09 Fair CLR 26.2 22.1 78% 28 76.3 0.0
12 07:35 S 11 16.09 Fair CLR 25.9 22.2 80% 27 76.28 0.0
12 07:15 S 9 16.09 Fair CLR 25.5 22.2 82% 27 76.28 0.0
12 06:55 S 7 16.09 Fair CLR 24.6 22.7 24.8 22.2 89% 25 76.25 0.0
12 06:35 Calm 16.09 Fair CLR 23 22.7 98% 76.25 0.0
12 06:15 Calm 11.27 Fair CLR 22.6 22.5 99% 76.25 0.0
12 05:55 Calm 11.27 Fair CLR 22.7 22.2 97% 76.23 0.0
12 05:35 SE 6 11.27 Fair CLR 22.6 22.4 99% 76.23 0.0
12 05:15 Calm 16.09 Fair CLR 22.6 22.3 98% 76.23 0.0
12 04:55 Calm 16.09 Fair CLR 22.8 22.4 98% 76.23 0.0
12 04:15 Calm 11.27 Fair CLR 22.8 22.7 99% 76.23 0.0
12 03:55 E 6 16.09 Fair CLR 22.9 22.8 99% 76.2 0.0
12 03:35 Calm 11.27 Fair CLR 22.6 22.5 99% 76.23 0.0
12 03:15 Calm 16.09 Fair CLR 22.8 22.8 100% 76.23 0.0
12 02:55 Calm 16.09 Fair CLR 23.1 23 99% 76.2 0.0
12 02:35 Calm 11.27 Fair CLR 23.1 22.9 99% 76.2 0.0
12 02:15 Calm 16.09 Fair CLR 23.7 23 96% 76.2 0.0
12 01:55 N 6 16.09 Fair CLR 23.5 23.3 99% 76.2 0.0
12 01:35 Calm 16.09 Fair CLR 23.2 22.9 98% 76.23 0.0
12 01:15 Calm 16.09 Fair CLR 23.3 23 98% 76.25 0.0
12 00:55 Calm 16.09 Fair CLR 23.6 23.2 31 23.6 98% 76.25 0.0
12 00:35 Calm 11.27 Fair CLR 24.1 23.2 95% 23 76.25 0.0
12 00:15 Calm 16.09 Fair CLR 24 23.3 96% 23 76.25 0.0
11 23:55 S 6 16.09 Fair CLR 24.8 23.2 91% 25 76.23 0.0
11 23:35 SW 7 16.09 Fair CLR 25.3 23.2 88% 26 76.23 0.0
11 23:15 SW 7 16.09 Fair CLR 25.8 23 85% 27 76.23 0.0
11 22:55 S 7 16.09 Fair CLR 26.7 22.5 78% 29 76.23 0.0
11 22:35 S 7 16.09 Fair CLR 26.2 22.5 80% 28 76.2 0.0
11 22:15 SW 7 16.09 Fair CLR 26 22.5 81% 28 76.17 0.0
11 21:55 S 6 16.09 Fair CLR 26.4 22.3 78% 28 76.17 0.0
11 21:35 S 9 16.09 Fair CLR 27.2 22.1 74% 30 76.12 0.0
11 21:15 S 9 16.09 Fair CLR 27.6 22 72% 30 76.1 0.0
11 20:55 S 9 16.09 Fair CLR 28.2 21.8 68% 31 76.1 0.0
11 20:35 S 7 16.09 Fair CLR 28.8 21.7 66% 32 76.07 0.0
11 20:15 S 9 16.09 Fair CLR 29 21.9 66% 32 76.07 0.0
11 19:55 SE 9 16.09 Fair CLR 29.6 21.7 63% 33 76.07 0.0
11 19:35 S 11 16.09 Fair CLR 29.8 21.4 61% 33 76.05 0.0
11 19:15 S 17 16.09 Fair CLR 30.7 21.2 57% 34 76.07 0.0
11 18:55 S 11 16.09 Fair CLR 31.1 21.6 33.2 30.3 57% 34 76.07 0.0 0.03
11 18:35 S 13 16.09 Partly Cloudy SCT050 SCT065 31.4 21.2 55% 34 76.07 0.0
11 18:15 S 15 16.09 Mostly Cloudy SCT050 BKN065 31.5 21.1 54% 34 76.07 0.0
11 17:55 S 11 16.09 Mostly Cloudy BKN050 BKN065 31.2 21.3 56% 34 76.1 0.0
11 17:35 SW 11 16.09 Partly Cloudy SCT055 SCT065 31.7 21.5 55% 35 76.1 0.0
11 17:15 SW 13 16.09 Partly Cloudy SCT055 32 21.3 53% 35 76.1 0.0
11 16:55 W 17 16.09 Partly Cloudy SCT048 32.8 21.1 50% 36 76.1 0.0
11 16:35 SW 19 16.09 Partly Cloudy SCT048 32.7 21.4 51% 36 76.1 0.0
11 16:15 SW 13 16.09 Partly Cloudy SCT048 32.7 21.4 51% 36 76.12 0.0
11 15:55 S 15 16.09 Partly Cloudy SCT046 32.8 21.2 50% 36 76.12 0.0 0.03
11 15:35 S 15 16.09 Partly Cloudy SCT046 SCT060 SCT070 32.5 21.3 52% 36 76.15 0.0
11 15:15 SW 19 16.09 Mostly Cloudy BKN044 BKN060 BKN070 32.1 21.1 52% 35 76.15 0.0
11 14:55 W 11 16.09 Partly Cloudy SCT048 SCT055 32 21.3 53% 35 76.17 0.0
11 14:35 SW 11 16.09 Partly Cloudy SCT060 SCT085 32.2 21.8 54% 36 76.2 0.0
11 14:15 NW 9 16.09 Mostly Cloudy SCT043 BKN055 31.2 21.9 58% 35 76.2 0.0
11 13:35 SW 11 16.09 Mostly Cloudy SCT041 BKN065 BKN070 30.8 21.7 58% 34 76.23 0.0
11 13:15 W 7 16.09 Mostly Cloudy SCT041 SCT050 BKN065 31.4 21.8 57% 35 76.23 0.0
11 12:55 SW 13 16.09 Mostly Cloudy SCT041 SCT050 BKN065 30.8 21.3 32.4 23.8 57% 34 76.25 0.0 0.08
11 12:35 SW 11 16.09 Mostly Cloudy SCT041 BKN049 BKN070 30.9 21.2 56% 34 76.25 0.0
11 12:15 SW 13 16.09 Mostly Cloudy BKN043 BKN049 BKN070 31 21.8 58% 34 76.25 0.0
11 11:55 W 15 16.09 Mostly Cloudy SCT043 SCT050 BKN060 31.2 20.9 54% 34 76.25 0.0 0.03
11 11:35 W 9 16.09 Partly Cloudy SCT044 SCT050 31.1 20.7 54% 34 76.25 0.0 0.03
11 11:15 SW 13 16.09 Fair CLR 30.9 20.9 55% 34 76.23 0.0
11 10:55 SW 19 16.09 Partly Cloudy SCT035 30.3 20.8 57% 33 76.25 0.0
11 10:35 W 15 16.09 Partly Cloudy SCT035 SCT042 29.9 20.9 59% 32 76.25 0.0
11 10:15 SW 11 16.09 Partly Cloudy SCT033 SCT042 29.9 21.1 59% 32 76.25 0.0
11 09:55 W 13 16.09 Partly Cloudy SCT031 29.7 21.5 61% 33 76.28 0.0 0.03 0.05
11 09:35 SW 13 16.09 Fair CLR 29.3 21.2 62% 32 76.28 0.0 0.03
11 09:15 SW 13 16.09 Fair CLR 28.8 21.9 66% 32 76.28 0.0
11 08:55 SW 17 16.09 Fair CLR 28.2 21.9 69% 31 76.25 0.0
11 08:35 SW 11 16.09 Fair CLR 27.6 22 72% 30 76.25 0.0
11 08:15 S 13 16.09 Fair CLR 27.2 21.9 73% 29 76.25 0.0
11 07:55 S 13 16.09 Fair CLR 26.7 21.8 75% 29 76.23 0.0 0.03
11 07:35 S 9 16.09 Fair CLR 25.9 21.5 77% 27 76.25 0.0 0.03
11 07:15 Calm 16.09 Fair CLR 24.5 21.8 85% 25 76.25 0.0
11 06:55 SE 7 16.09 Fair CLR 23.7 21.7 23.8 21.5 89% 76.23 0.0 0.08
11 06:35 SE 6 16.09 Fair CLR 22.7 21.9 95% 76.25 0.0
11 06:15 Calm 16.09 Fair CLR 21.9 21.7 99% 76.25 0.0
11 05:55 Calm 16.09 Fair CLR 21.6 21.4 99% 76.25 0.0 0.03
11 05:35 SE 6 16.09 Fair CLR 21.7 21.6 99% 76.23 0.0 0.03
11 05:15 Calm 16.09 Fair CLR 21.8 21.6 99% 76.23 0.0
11 04:55 Calm 16.09 Fair CLR 21.9 21.6 98% 76.23 0.0
11 04:35 Calm 16.09 Fair CLR 22.1 21.7 98% 76.2 0.0
11 04:15 Calm 16.09 Fair CLR 22.2 21.6 96% 76.23 0.0
11 03:55 S 6 16.09 Fair CLR 22.6 21.7 95% 76.2 0.0 0.03 0.05
11 03:35 SE 6 16.09 Fair CLR 22.5 21.9 96% 76.2 0.0 0.03
11 03:15 E 6 16.09 Fair CLR 22.5 21.9 96% 76.2 0.0
11 02:55 E 7 16.09 Fair CLR 22.7 22 96% 76.17 0.0
11 02:35 S 6 16.09 Fair CLR 22.7 21.9 95% 76.17 0.0
11 02:15 Calm 16.09 Fair CLR 22.4 22 98% 76.2 0.0
11 01:55 Calm 16.09 Fair CLR 22.2 22 99% 76.2 0.0 0.03
11 01:35 Calm 16.09 Fair CLR 22.5 21.9 96% 76.17 0.0 0.03
11 01:15 Calm 16.09 Fair CLR 22.9 22.1 95% 76.17 0.0
11 00:55 Calm 16.09 Fair CLR 22.6 22.2 30.1 22.6 98% 76.17 0.0 0.08
11 00:35 Calm 16.09 Fair CLR 22.8 22.2 96% 76.15 0.0
11 00:15 SE 6 16.09 Fair CLR 23.9 22 89% 23 76.15 0.0
10 23:55 Calm 16.09 Fair CLR 23.3 22.2 94% 76.17 0.0 0.03
10 23:35 Calm 16.09 Fair CLR 24.5 21.9 86% 25 76.17 0.0 0.03
10 23:15 S 6 16.09 Fair CLR 25 21.9 83% 26 76.17 0.0
10 22:55 S 7 16.09 Fair CLR 25.4 21.7 80% 27 76.2 0.0
10 22:35 SE 6 16.09 Fair CLR 24.8 21.8 83% 25 76.2 0.0
10 22:15 SE 6 16.09 Fair CLR 25.6 21.6 79% 27 76.2 0.0
10 21:55 S 9 16.09 Fair CLR 26.3 21.3 74% 28 76.2 0.0 0.03 0.05
10 21:35 S 9 16.09 Fair CLR 26.2 21.3 74% 28 76.17 0.0
10 21:15 S 11 16.09 Fair CLR 27.9 21.1 67% 30 76.15 0.0
10 20:55 S 11 16.09 Fair CLR 27 21.4 71% 29 76.17 0.0 0.03
10 20:35 S 9 16.09 Fair CLR 27.1 21.5 72% 29 76.15 0.0 0.03
10 20:15 SW 9 16.09 Fair CLR 27.8 21.3 68% 30 76.15 0.0 0.03
10 19:55 S 11 16.09 Fair CLR 28 21.4 67% 30 76.15 0.0
10 19:35 SW 11 16.09 Fair CLR 28.9 21 62% 31 76.15 0.0
10 19:15 S 13 16.09 Fair CLR 29.8 20.9 59% 32 76.15 0.0
10 18:55 SW 15 16.09 Fair CLR 30.3 20.8 32.9 30.1 57% 33 76.15 0.0 0.05 0.23
10 18:35 SW 11 16.09 Fair CLR 31 21.1 56% 34 76.12 0.0 0.03
10 18:15 S 17 16.09 Fair CLR 31.6 20.5 52% 34 76.12 0.0 0.03
10 17:55 SW 19 16.09 Fair CLR 31.9 20.7 52% 35 76.12 0.0 0.03
10 17:35 S 20 16.09 Fair CLR 31.8 20.8 52% 35 76.12 0.0 0.03
10 17:15 S 19 16.09 Fair CLR 32.1 20.6 51% 35 76.12 0.0
10 16:55 S 19 16.09 Fair CLR 32 21.1 52% 35 76.15 0.0 0.05
10 16:35 S 20 16.09 Fair CLR 32.6 21.2 51% 36 76.15 0.0 0.03
10 16:15 SW 15 16.09 Partly Cloudy SCT046 SCT060 32.3 21.2 52% 35 76.17 0.0 0.03
10 15:55 S 19 16.09 Partly Cloudy SCT046 SCT060 32.6 21 50% 36 76.17 0.0 0.03 0.1
10 15:35 S 15 16.09 Partly Cloudy SCT050 32.2 20.6 50% 35 76.2 0.0 0.03
10 15:15 S 17 16.09 Partly Cloudy SCT065 32.6 21.2 51% 36 76.23 0.0
10 14:55 SW 15 16.09 Mostly Cloudy SCT043 SCT050 BKN065 32.4 20.4 49% 35 76.23 0.0 0.03
10 14:35 SW 17 16.09 Partly Cloudy SCT043 SCT050 SCT075 32.2 21.3 53% 35 76.25 0.0 0.03
10 13:55 W 9 16.09 Partly Cloudy SCT043 SCT055 SCT070 31.4 21.6 56% 35 76.3 0.0 0.03
10 13:35 S 17 16.09 Mostly Cloudy BKN042 BKN050 BKN075 30.9 20.8 55% 33 76.33 0.0
10 13:15 SW 11 16.09 Mostly Cloudy SCT035 SCT049 BKN075 30.9 21.4 57% 34 76.35 0.0
10 12:55 SW 17 16.09 Partly Cloudy SCT060 SCT070 31.1 21.5 31.4 23.2 57% 34 76.35 0.0 0.03 0.18
10 12:35 SW 9 16.09 Mostly Cloudy SCT033 SCT038 BKN055 30.6 21.7 59% 34 76.38 0.0 0.03
10 12:15 S 11 16.09 Partly Cloudy SCT027 SCT034 SCT048 30.3 21.8 60% 34 76.4 0.0
10 11:55 S 6 16.09 Partly Cloudy SCT029 SCT042 30.4 22.2 62% 34 76.4 0.0 0.03
10 11:15 SW 13 16.09 Mostly Cloudy SCT026 SCT034 BKN060 28.8 22.9 70% 32 76.45 0.0
10 10:55 S 9 16.09 Mostly Cloudy SCT024 BKN065 28.6 22.5 70% 32 76.45 0.0 0.03
10 10:35 W 11 16.09 Partly Cloudy SCT026 SCT041 SCT065 29 23 70% 33 76.45 0.0
10 10:15 SW 13 16.09 Partly Cloudy SCT034 SCT040 SCT070 28.1 22.4 71% 31 76.45 0.0
10 09:55 SW 11 16.09 Overcast SCT022 BKN034 OVC070 27.1 22.3 75% 29 76.48 0.0 0.03 0.1
10 09:35 S 11 16.09 Mostly Cloudy SCT034 BKN060 27.4 21.7 71% 30 76.48 0.0 0.03
10 09:15 S 9 16.09 Fair CLR 26.9 21.7 73% 29 76.5 0.0
10 08:55 SW 11 16.09 Partly Cloudy SCT036 26.5 21.8 75% 28 76.5 0.0 0.05
10 08:35 S 13 16.09 Partly Cloudy SCT038 SCT043 26.7 21.2 72% 28 76.5 0.0 0.05
10 08:15 S 11 16.09 Partly Cloudy SCT039 SCT050 25.8 21.5 77% 27 76.48 0.0 0.03
10 07:55 SE 11 16.09 Mostly Cloudy SCT039 BKN048 25.6 21.4 78% 27 76.48 0.0
10 07:35 Calm 16.09 Partly Cloudy SCT045 SCT050 24.7 22.2 86% 25 76.45 0.0
10 07:15 E 6 16.09 Mostly Cloudy SCT043 BKN049 23.9 22.3 91% 23 76.45 0.0
10 06:55 E 7 16.09 Partly Cloudy SCT045 23.1 22.2 24 20.9 95% 76.45 0.0 0.1
10 06:35 E 7 16.09 Partly Cloudy SCT045 22.5 22.1 98% 76.45 0.0
10 06:15 E 6 11.27 Fair CLR 21.8 21.7 99% 76.45 0.0
10 05:35 SE 6 16.09 Fair CLR 21.8 21.7 99% 76.4 0.0
10 04:55 Calm 11.27 Fair CLR 21.2 21.2 100% 76.4 0.0 0.03
10 04:35 Calm 16.09 Fair CLR 21.4 21.1 98% 76.4 0.0 0.03
10 04:15 Calm 16.09 Fair CLR 21.5 21.2 98% 76.4 0.0
10 03:55 SE 6 16.09 Fair CLR 22.3 21.4 95% 76.4 0.0 0.03 0.05
10 03:35 SE 9 16.09 Fair CLR 22.7 21.7 94% 76.38 0.0 0.03
10 03:15 SE 7 16.09 Fair CLR 22.1 21.7 98% 76.38 0.0 0.03
10 02:55 SE 6 16.09 Fair CLR 21.8 21.5 98% 76.38 0.0
10 02:35 Calm 16.09 Fair CLR 22 21.6 98% 76.4 0.0
10 02:15 Calm 16.09 Fair CLR 22.1 21.8 98% 76.38 0.0
10 01:55 Calm 16.09 Fair CLR 22.3 21.9 98% 76.38 0.0 0.03
10 01:35 Calm 16.09 Fair CLR 22.8 21.9 95% 76.38 0.0
10 01:15 SE 6 16.09 Partly Cloudy SCT043 23.9 21.8 88% 24 76.38 0.0
10 00:55 SE 7 11.27 Partly Cloudy SCT043 23.6 22.1 29.7 23.3 91% 76.4 0.0 0.03 0.15
10 00:35 Calm 16.09 Fair CLR 23.4 22.5 95% 76.38 0.0 0.03
10 00:15 Calm 8.05 Fog/Mist CLR 24.2 22 88% 24 76.38 0.0
09 23:55 Calm 16.09 Fair CLR 24.2 22.4 90% 24 76.38 0.0 0.03
09 23:35 SE 7 16.09 Fair CLR 24.2 22.7 91% 24 76.38 0.0 0.03
09 23:15 Calm 16.09 Fair CLR 25 22.4 86% 26 76.38 0.0
09 22:55 E 7 16.09 Fair CLR 25.6 22.1 81% 27 76.35 0.0 0.03
09 22:35 SW 13 16.09 Fair CLR 26.1 22.3 80% 28 76.33 0.0 0.03
09 22:15 S 15 16.09 Fair CLR 25.3 22.4 84% 26 76.38 0.0 0.03
09 21:55 SE 7 16.09 Fair CLR 26.2 21.9 77% 28 76.4 0.0 0.03 0.08
09 21:35 SE 6 16.09 Fair CLR 26.7 22.1 76% 29 76.4 0.0 0.03
09 21:15 SE 6 16.09 Fair CLR 26.7 22.1 76% 29 76.4 0.0 0.03
09 20:55 SE 11 16.09 Fair CLR 26.8 22.2 76% 29 76.38 0.0 0.03
09 20:35 SE 9 16.09 Fair CLR 27.3 22.1 73% 30 76.38 0.0 0.03
09 20:15 SE 9 16.09 Fair CLR 27.9 22.4 72% 31 76.43 0.0 0.03
09 19:55 SE 6 16.09 Fair CLR 28.5 22.1 68% 31 76.45 0.0 0.03
09 19:35 SE 6 16.09 Partly Cloudy SCT046 SCT080 28.6 23.5 74% 33 76.45 0.0 0.03
09 19:15 Calm 16.09 Mostly Cloudy BKN046 BKN080 28.7 23.2 72% 32 76.48 0.0 0.03
09 18:55 S 7 16.09 Partly Cloudy BKN046 SCT055 29.6 21.8 32.1 29.6 63% 33 76.48 0.0 0.03 0.28
09 18:35 SW 7 16.09 Overcast BKN042 OVC048 30.1 21.7 61% 33 76.48 0.0 0.03
09 18:15 SW 6 16.09 Overcast BKN044 OVC070 30 21.7 61% 33 76.5 0.0 0.03
09 17:55 SW 7 16.09 Partly Cloudy SCT048 SCT070 29.9 21.7 61% 33 76.48 0.0 0.05
09 17:35 SW 9 16.09 Partly Cloudy SCT043 SCT050 SCT070 30.2 21.3 59% 33 76.45 0.0 0.05
Date Time (cdt) Wind (kph) Vis. (km) Weather Sky Cond. Air Dwpt Max. Min. Relative Humidity Wind Chill (°C) Heat Index (°C) altimeter (cm) sea level (mb) 1 hr 3 hr 6 hr
6 hour
Temperature (ºC) Pressure Precipitation (cm)