Weather observations for the past three days for
Mackinac Island Airport
Metric (Imperial)
Date Time (edt) 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.
10 08:35 Vrbl 4 16.09 Overcast OVC045 1 -1 87% 76.68 0.0
10 08:15 SE 7 16.09 Mostly Cloudy BKN043 BKN060 BKN085 1 -1 87% -1 76.66 0.0
10 07:55 SE 13 16.09 Mostly Cloudy SCT030 BKN060 BKN090 0 -1 1.7 0.3 93% -4 76.66 0.0
10 07:35 S 9 16.09 Mostly Cloudy SCT060 BKN090 1 -1 87% -2 76.63 0.0
10 07:15 SE 11 16.09 Overcast SCT029 OVC090 1 -2 81% -2 76.63 0.0
10 06:56 Vrbl 11 16.09 Overcast BKN029 OVC100 1 -2 81% -2 76.63 0.0
10 06:35 SE 7 16.09 Overcast SCT033 OVC100 1 -2 81% -1 76.63 0.0
10 06:15 S 11 16.09 Overcast BKN035 OVC100 1 -2 81% -2 76.66 0.0
10 05:55 SE 11 16.09 Overcast FEW035 OVC090 2 -2 75% -1 76.66 0.0
10 05:35 S 15 16.09 Mostly Cloudy BKN090 1 -2 81% -3 76.66 0.0
10 05:15 S 13 16.09 A Few Clouds FEW050 FEW070 1 -2 81% -2 76.68 0.0
10 04:55 S 9 16.09 Mostly Cloudy BKN050 BKN070 1 -2 81% -2 76.71 0.0
10 04:36 S 13 16.09 Overcast OVC050 1 -2 81% -2 76.71 0.0
10 04:15 S 11 16.09 Overcast BKN050 OVC055 1 -2 81% -2 76.68 0.0
10 03:55 Vrbl 7 16.09 Overcast BKN055 OVC090 1 -2 81% -1 76.66 0.0
10 03:35 SE 7 16.09 Overcast SCT055 OVC090 1 -2 81% -1 76.66 0.0
10 03:15 SE 7 16.09 Overcast SCT055 OVC100 1 -2 81% -1 76.63 0.0
10 02:55 E 9 16.09 Overcast SCT055 BKN065 OVC100 1 -2 81% -2 76.58 0.0
10 02:35 SE 7 16.09 Overcast FEW055 BKN100 OVC120 1 -2 81% -1 76.61 0.0
10 02:16 E 7 16.09 Overcast OVC110 1 -2 81% -1 76.61 0.0
10 01:55 E 7 16.09 Overcast OVC110 1 -2 3.2 0.2 81% -1 76.63 0.0
10 01:35 E 9 16.09 Overcast OVC110 1 -2 81% -2 76.63 0.0
10 01:15 E 7 16.09 Partly Cloudy SCT120 0 -2 87% -2 76.66 0.0
10 00:55 E 9 16.09 Fair CLR 1 -3 75% -2 76.68 0.0
10 00:35 NE 9 16.09 Fair CLR 1 -3 75% -2 76.68 0.0
10 00:15 NE 13 16.09 Fair CLR 1 -2 81% -2 76.68 0.0
09 23:56 NE 13 16.09 Fair CLR 1 -2 81% -2 76.66 0.0
09 23:35 NE 13 16.09 Fair CLR 1 -2 81% -2 76.66 0.0
09 23:15 N 13 16.09 Fair CLR 1 -2 81% -2 76.63 0.0
09 22:55 N 9 16.09 Fair CLR 1 -2 81% -2 76.66 0.0
09 22:35 NW 9 16.09 Fair CLR 1 -2 81% -2 76.68 0.0
09 22:15 NW 11 16.09 A Few Clouds FEW055 2 -2 75% -1 76.71 0.0
09 21:55 NW 7 16.09 Mostly Cloudy BKN055 2 -2 75% 0 76.71 0.0
09 21:36 W 11 16.09 Overcast OVC049 3 -2 70% 0 76.73 0.0
09 21:15 W 13 16.09 Overcast OVC049 2 -2 75% -1 76.73 0.0
09 20:55 W 19 16.09 Mostly Cloudy BKN049 2 -2 75% -2 76.71 0.0
09 20:35 W 22 16.09 Fair CLR 2 -2 75% -3 76.68 0.0
09 20:15 W 17 16.09 Fair CLR 2 -2 75% -2 76.66 0.0
09 19:55 W 9 16.09 Fair CLR 3 -2 4.5 2.9 70% 1 76.63 0.0
09 19:35 W 11 16.09 Fair CLR 4 -2 65% 2 76.58 0.0
09 19:16 W 15 16.09 Fair CLR 4 -2 65% 1 76.58 0.0
09 18:55 W 13 16.09 Fair CLR 4 -2 65% 1 76.56 0.0
09 18:35 W 17 G 26 16.09 Fair CLR 4 -2 65% 1 76.56 0.0
09 18:15 W 22 G 31 16.09 Fair CLR 4 -2 65% -0 76.56 0.0
09 17:55 SW 13 G 30 16.09 Fair CLR 3 -2 70% 0 76.53 0.0
09 17:35 W 17 16.09 Fair CLR 3 -2 70% -1 76.5 0.0
09 17:15 SW 22 G 31 16.09 Fair CLR 3 -2 70% -1 76.5 0.0
09 16:56 SW 24 G 35 16.09 Fair CLR 3 -2 70% -2 76.5 0.0
09 16:35 SW 20 G 35 16.09 Fair CLR 3 -2 70% -1 76.48 0.0
09 16:15 SW 20 G 35 16.09 Fair CLR 3 -2 70% -1 76.48 0.0
09 15:55 SW 31 16.09 Fair CLR 3 -2 70% -2 76.45 0.0
09 15:35 SW 31 G 39 16.09 Fair CLR 3 -2 70% -2 76.43 0.0
09 15:15 SW 30 G 41 16.09 Fair CLR 3 -2 70% -2 76.43 0.0
09 14:55 SW 20 G 37 16.09 Fair CLR 3 -2 70% -1 76.43 0.0
09 14:36 SW 19 G 35 16.09 Fair CLR 3 -2 70% -1 76.4 0.0
09 14:15 SW 24 G 35 16.09 Fair CLR 3 -2 70% -2 76.38 0.0
09 13:55 SW 22 G 35 16.09 Fair CLR 3 -1 5.8 2.8 75% -1 76.35 0.0
09 13:35 SW 24 G 35 16.09 Fair CLR 3 -2 70% -2 76.33 0.0
09 13:15 W 20 G 35 16.09 Fair CLR 3 -2 70% -1 76.3 0.0
09 12:55 W 19 G 31 16.09 Fair CLR 4 -2 65% 0 76.28 0.0
09 12:35 W 30 G 43 16.09 Fair CLR 4 -2 65% -1 76.25 0.0
09 12:16 W 24 G 39 16.09 Fair CLR 4 -2 65% -0 76.23 0.0
09 11:55 W 30 G 37 16.09 A Few Clouds FEW029 4 -1 70% -1 76.2 0.0
09 11:35 W 28 G 37 16.09 Mostly Cloudy BKN027 BKN031 5 -1 66% 1 76.17 0.0
09 11:15 W 31 16.09 Mostly Cloudy BKN023 BKN031 4 -1 70% -1 76.15 0.0
09 10:55 W 24 G 35 16.09 Overcast BKN018 OVC025 4 0 75% -0 76.12 0.0
09 10:35 W 22 16.09 Overcast BKN020 OVC024 4 1 81% -0 76.07 0.0
09 10:15 W 26 16.09 Mostly Cloudy BKN022 BKN030 BKN038 4 1 81% -0 76.05 0.0
09 09:56 W 37 G 46 16.09 A Few Clouds and Breezy FEW038 4 1 81% -1 76 0.0
09 09:35 W 24 G 43 16.09 Fair CLR 4 1 81% -0 75.97 0.0
09 09:15 W 26 G 43 16.09 Fair CLR 4 1 81% -0 75.92 0.0
09 08:55 SW 31 G 44 16.09 Fair CLR 3 2 93% -2 75.9 0.0
09 08:35 W 31 G 50 16.09 Fair CLR 4 3 93% -1 75.87 0.0
09 08:15 SW 30 G 44 16.09 Fair CLR 5 4 93% 0 75.84 0.0
09 07:55 SW 22 8.05 Fog/Mist CLR 5 5 9 3.4 100% 1 75.82 0.0
09 07:36 SW 20 9.66 Fog/Mist CLR 5 5 100% 1 75.77 0.0
09 07:15 SW 20 4.02 Fog/Mist SCT001 5 5 100% 1 75.77 0.0
09 06:55 S 19 2.01 Fog/Mist OVC001 5 5 100% 2 75.74 0.0
09 06:35 S 20 1.61 Fog/Mist OVC001 5 5 100% 1 75.74 0.0
09 06:15 S 17 G 28 1.61 Fog/Mist OVC001 4 4 100% 1 75.77 0.0
09 05:55 SW 20 1.21 Fog/Mist BKN001 4 4 100% 0 75.77 0.0
09 05:35 SW 15 3.22 Fog/Mist OVC001 4 4 100% 1 75.77 0.0
09 05:16 SW 17 4.83 Fog/Mist OVC001 4 4 100% 1 75.77 0.0
09 04:55 SW 19 3.22 Light Drizzle Fog/Mist OVC001 4 4 100% 0 75.77 0.0 0.08
09 04:35 SW 22 G 41 6.44 Light Rain Fog/Mist BKN003 BKN014 BKN055 4 4 100% -0 75.77 0.0
09 04:15 SW 28 G 35 6.44 Light Rain Fog/Mist BKN003 BKN044 OVC055 4 3 93% -1 75.77 0.0
09 03:55 SW 26 G 43 6.44 Light Rain Fog/Mist BKN008 OVC013 4 3 93% -0 75.77 0.0 0.13
09 03:35 SW 33 G 56 6.44 Light Rain Fog/Mist and Breezy FEW004 OVC015 5 4 93% 0 75.74 0.0
09 03:15 W 26 G 41 8.05 Light Rain Fog/Mist SCT005 BKN014 OVC050 5 5 100% 1 75.77 0.0
09 02:56 SW 19 11.27 Light Rain BKN050 OVC060 5 4 93% 2 75.72 0.0
09 02:35 SW 20 G 35 14.48 Light Rain OVC060 5 3 87% 1 75.74 0.0
09 02:15 SW 24 G 37 16.09 Light Rain SCT042 BKN048 OVC050 9 4 71% 6 75.77 0.0
09 01:55 SW 26 G 33 16.09 Light Rain BKN040 BKN048 OVC060 9 3 10.3 1.4 66% 6 75.74 0.0
09 01:35 SW 26 G 41 16.09 Light Rain OVC050 10 2 58% 7 75.74 0.0
09 01:15 S 28 G 48 16.09 Light Rain BKN060 OVC075 10 1 54% 7 75.72 0.0
09 00:55 S 30 G 50 16.09 Overcast BKN070 OVC085 10 1 54% 7 75.72 0.0
09 00:36 S 33 G 46 16.09 Overcast and Breezy OVC070 10 1 54% 7 75.74 0.0
09 00:15 S 31 G 57 16.09 Light Drizzle OVC070 10 1 54% 7 75.74 0.0
08 23:55 S 30 G 46 16.09 Light Rain OVC070 9 1 58% 6 75.77 0.0
08 23:35 S 31 G 43 16.09 Overcast BKN070 OVC080 9 0 54% 5 75.79 0.0
08 23:15 S 28 G 41 16.09 Overcast BKN070 OVC080 8 -1 53% 4 75.79 0.0
08 22:55 S 22 G 33 16.09 Light Rain BKN075 OVC090 8 -1 53% 5 75.82 0.0
08 22:35 S 20 G 31 16.09 Overcast BKN075 OVC090 8 -1 53% 5 75.87 0.0
08 22:16 SE 24 16.09 Light Rain OVC075 7 -1 57% 4 75.9 0.0
08 21:55 SE 19 16.09 Overcast OVC075 5 -1 66% 2 75.92 0.0
08 21:35 SE 19 16.09 Light Rain BKN075 OVC085 3 -1 75% -1 75.95 0.0
08 21:15 SE 17 16.09 Mostly Cloudy BKN075 2 -1 81% -2 75.97 0.0
08 20:55 SE 15 16.09 Fair CLR 2 -1 81% -2 76 0.0
08 20:35 E 15 16.09 Fair CLR 2 -1 81% -2 76 0.0
08 20:15 E 17 16.09 Fair CLR 2 -1 81% -2 76 0.0
08 19:56 E 19 16.09 Fair CLR 1 -1 87% -3 76.02 0.0
08 19:35 E 15 16.09 Fair CLR 2 -1 81% -2 76.02 0.0
08 19:15 E 19 16.09 Fair CLR 2 -1 81% -2 76.02 0.0
08 18:55 E 19 G 33 16.09 Fair CLR 2 -1 81% -2 76.05 0.0
08 18:35 E 30 G 43 16.09 Fair CLR 2 -2 75% -3 76.07 0.0
08 18:15 E 30 G 43 16.09 Fair CLR 1 -2 81% -5 76.1 0.0
08 17:55 E 26 G 43 16.09 Fair CLR 1 -2 81% -4 76.15 0.0
08 17:36 E 22 G 39 16.09 A Few Clouds FEW110 1 -2 81% -4 76.17 0.0
08 17:15 E 24 G 39 16.09 Mostly Cloudy SCT100 BKN120 1 -2 81% -4 76.2 0.0
08 16:55 E 28 G 41 16.09 Overcast SCT090 OVC120 0 -2 87% -6 76.28 0.0
08 16:35 E 28 G 43 16.09 Partly Cloudy SCT090 SCT120 1 -2 81% -5 76.28 0.0
08 16:15 E 26 G 39 16.09 Partly Cloudy SCT070 SCT120 1 -2 81% -4 76.35 0.0
08 15:55 E 26 G 35 16.09 Overcast BKN070 OVC085 0 -2 87% -6 76.4 0.0
08 15:35 E 24 G 37 16.09 Overcast SCT060 OVC080 1 -2 81% -4 76.45 0.0
08 15:16 E 19 G 26 16.09 Overcast OVC060 1 -2 81% -3 76.5 0.0
08 14:55 E 17 16.09 Overcast OVC060 0 -2 87% -4 76.56 0.0
08 14:35 E 13 16.09 Light Rain OVC060 0 -3 80% -4 76.58 0.0
08 14:15 SE 19 G 28 16.09 Light Rain SCT041 OVC050 0 -4 75% -5 76.56 0.0
08 13:55 SE 17 G 28 16.09 Light Rain BKN041 OVC047 0 -4 0.2 -3.8 75% -4 76.61 0.0
08 13:35 SE 13 16.09 Unknown Precip OVC045 0 -3 80% -4 76.63 0.0
08 13:15 SE 15 G 26 16.09 Unknown Precip FEW032 BKN039 OVC047 0 -4 75% -4 76.66 0.0
08 12:56 SE 19 G 26 16.09 Light Snow BKN032 OVC039 0 -4 75% -5 76.71 0.0
08 12:35 SE 17 G 28 16.09 Overcast OVC034 -1 -4 80% -6 76.73 0.0
08 12:15 SE 19 G 31 8.05 Light Snow Haze OVC034 -1 -4 80% -6 76.78 0.0
08 11:55 S 22 G 30 8.05 Light Snow Haze OVC036 0 -5 69% -5 76.84 0.0
08 11:35 S 24 G 33 8.05 Light Snow Haze SCT028 BKN035 OVC042 -1 -5 75% -7 76.86 0.0
08 11:15 S 17 G 30 16.09 Overcast FEW034 BKN044 OVC050 -1 -6 69% -6 76.89 0.0
08 10:55 S 19 G 31 16.09 Overcast BKN050 OVC070 -1 -6 69% -6 76.86 0.0
08 10:36 S 19 16.09 Overcast BKN070 OVC080 -1 -6 69% -6 76.89 0.0
08 10:15 S 17 G 31 16.09 Overcast OVC075 -2 -6 74% -7 76.91 0.0
08 09:55 S 17 G 28 16.09 Overcast OVC080 -2 -7 69% -7 76.91 0.0
08 09:35 S 19 16.09 Overcast OVC090 -2 -7 69% -7 76.94 0.0
08 09:15 S 17 G 28 16.09 Mostly Cloudy BKN090 BKN120 -2 -7 69% -7 76.94 0.0
08 08:55 S 24 G 30 16.09 Mostly Cloudy BKN090 BKN120 -3 -7 74% -9 76.96 0.0
08 08:35 SE 22 G 35 16.09 Mostly Cloudy BKN090 BKN110 -3 -8 69% -9 76.96 0.0
08 08:16 SE 24 G 35 16.09 Mostly Cloudy SCT100 BKN120 -4 -8 74% -10 76.96 0.0
08 07:55 SE 28 G 37 16.09 Mostly Cloudy BKN110 -4 -8 -3.8 -5.4 74% -11 76.99 0.0
08 07:35 SE 22 G 33 16.09 Overcast OVC110 -4 -9 69% -10 77.01 0.0
08 07:15 S 24 G 35 16.09 Partly Cloudy SCT110 -4 -9 69% -10 77.04 0.0
08 06:55 S 24 G 35 16.09 Fair CLR -4 -9 69% -10 77.04 0.0
08 06:35 SE 22 G 30 16.09 Fair CLR -4 -9 69% -10 77.04 0.0
08 06:15 S 17 G 28 16.09 Fair CLR -4 -9 69% -9 77.06 0.0
08 05:56 SE 20 16.09 Fair CLR -5 -9 74% -11 77.06 0.0
08 05:35 S 17 16.09 Fair CLR -5 -9 74% -10 77.06 0.0
08 05:15 S 13 16.09 Fair CLR -5 -9 74% -10 77.09 0.0
08 04:55 S 17 16.09 Fair CLR -5 -9 74% -10 77.09 0.0
08 04:35 S 19 G 26 16.09 Fair CLR -5 -9 74% -11 77.14 0.0
08 04:15 SE 15 16.09 Fair CLR -5 -9 74% -10 77.14 0.0
08 03:55 S 15 16.09 Fair CLR -5 -9 74% -10 77.14 0.0
08 03:36 S 15 16.09 Fair CLR -5 -9 74% -10 77.14 0.0
08 03:15 S 13 16.09 Fair CLR -5 -9 74% -10 77.14 0.0
08 02:55 S 13 16.09 Fair CLR -5 -9 74% -10 77.14 0.0
08 02:35 SE 17 16.09 Fair CLR -5 -9 74% -10 77.17 0.0
08 02:15 S 15 16.09 Fair CLR -5 -9 74% -10 77.19 0.0
08 01:55 S 17 16.09 Fair CLR -4 -9 -2.6 -5.6 69% -9 77.19 0.0
08 01:35 S 13 16.09 Fair CLR -4 -9 69% -8 77.19 0.0
08 01:16 S 17 16.09 Fair CLR -4 -9 69% -9 77.22 0.0
08 00:55 SE 15 16.09 Fair CLR -4 -9 69% -9 77.22 0.0
08 00:35 S 15 16.09 Fair CLR -4 -10 63% -9 77.22 0.0
08 00:15 SE 15 16.09 Fair CLR -4 -10 63% -9 77.24 0.0
07 23:55 S 15 16.09 Fair CLR -4 -10 63% -9 77.24 0.0
07 23:35 S 11 16.09 Fair CLR -4 -10 63% -8 77.24 0.0
07 23:15 S 11 16.09 Fair CLR -5 -8 80% -9 77.24 0.0
07 22:56 S 9 16.09 Fair CLR -5 -8 80% -9 77.24 0.0
07 22:35 S 7 16.09 Fair CLR -5 -8 80% -8 77.24 0.0
07 22:15 SW 7 16.09 Fair CLR -5 -8 80% -8 77.24 0.0
07 21:55 SW 6 16.09 Fair CLR -4 -8 74% 77.24 0.0
07 21:35 SW 9 16.09 Fair CLR -4 -8 74% -7 77.24 0.0
07 21:15 W 11 16.09 Fair CLR -4 -8 74% -8 77.24 0.0
07 20:55 W 11 16.09 Fair CLR -4 -8 74% -8 77.24 0.0
07 20:36 SW 9 16.09 Fair CLR -3 -8 69% -6 77.24 0.0
07 20:15 SW 11 16.09 Fair CLR -3 -8 69% -7 77.24 0.0
07 19:55 W 11 16.09 Fair CLR -3 -9 -1.8 -3.2 64% -7 77.27 0.0
07 19:35 W 13 16.09 Fair CLR -2 -9 59% -6 77.27 0.0
07 19:15 W 20 G 30 16.09 Fair CLR -3 -9 64% -9 77.29 0.0
07 18:55 W 19 G 30 16.09 Fair CLR -2 -8 64% -7 77.29 0.0
07 18:35 W 17 G 30 16.09 Fair CLR -2 -9 59% -7 77.29 0.0
07 18:16 W 19 G 28 16.09 Fair CLR -2 -9 59% -7 77.29 0.0
07 17:55 W 20 G 28 16.09 Fair CLR -2 -9 59% -7 77.32 0.0
07 17:35 SW 26 G 31 16.09 Fair CLR -2 -9 59% -8 77.32 0.0
07 17:15 W 19 G 26 16.09 Fair CLR -2 -9 59% -7 77.32 0.0
07 16:55 SW 22 G 31 16.09 Fair CLR -2 -9 59% -8 77.32 0.0
07 16:35 SW 22 G 31 16.09 Fair CLR -2 -9 59% -8 77.34 0.0
07 16:15 SW 20 G 35 16.09 A Few Clouds FEW031 -2 -9 59% -7 77.34 0.0
07 15:56 SW 22 G 30 16.09 A Few Clouds FEW031 -2 -9 59% -8 77.37 0.0
07 15:35 W 24 G 31 16.09 A Few Clouds FEW033 -2 -8 64% -8 77.39 0.0
07 15:15 SW 24 G 35 16.09 Mostly Cloudy BKN037 -2 -8 64% -8 77.42 0.0
07 14:55 SW 19 G 33 16.09 Overcast OVC037 -2 -9 59% -7 77.42 0.0
07 14:35 SW 20 G 33 16.09 Mostly Cloudy BKN037 -2 -8 64% -7 77.42 0.0
07 14:15 W 24 G 37 16.09 Partly Cloudy FEW029 SCT034 -2 -9 59% -8 77.42 0.0
07 13:55 SW 22 G 35 16.09 Overcast BKN029 BKN033 OVC040 -3 -9 -2.5 -11.4 64% -9 77.44 0.0
07 13:36 SW 19 G 35 16.09 Overcast BKN027 OVC036 -3 -9 64% -8 77.44 0.0
07 13:15 SW 22 G 35 16.09 Overcast BKN029 OVC036 -3 -10 59% -9 77.44 0.0
07 12:55 SW 19 G 30 16.09 Overcast SCT028 OVC036 -4 -9 69% -10 77.44 0.0
07 12:35 SW 22 G 35 16.09 Overcast BKN026 OVC034 -4 -9 69% -10 77.47 0.0
07 12:15 W 20 G 31 16.09 Mostly Cloudy SCT026 BKN033 BKN039 -4 -10 63% -10 77.47 0.0
07 11:55 SW 11 16.09 Partly Cloudy FEW028 SCT035 SCT041 -4 -10 63% -8 77.47 0.0
07 11:35 SW 13 16.09 Fair CLR -5 -11 63% -10 77.47 0.0
07 11:16 W 13 16.09 Partly Cloudy SCT045 -5 -12 58% -10 77.47 0.0
07 10:55 SW 15 16.09 Partly Cloudy SCT045 -6 -12 63% -11 77.47 0.0
07 10:35 W 19 16.09 A Few Clouds FEW047 -6 -12 63% -12 77.47 0.0
07 10:15 SW 11 16.09 Fair CLR -7 -12 68% -12 77.44 0.0
07 09:55 SW 13 16.09 Fair CLR -7 -12 68% -12 77.44 0.0
07 09:35 Vrbl 11 16.09 Fair CLR -8 -14 62% -13 77.42 0.0
07 09:15 S 15 16.09 A Few Clouds FEW045 -8 -13 68% -14 77.39 0.0
07 08:56 S 13 16.09 A Few Clouds FEW045 -8 -13 68% -13 77.39 0.0
Date Time (edt) 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)