Altocumulus Average Cloud Amount (%) September (1954 - 1997) Night, Ship Observations Only Global Average: 16.6 Zonal Averages 15 zones Lat.N Average 85 16.6 75 15.6 65 17.8 55 16.3 45 16.1 35 14.0 25 12.5 15 16.8 5 22.1 -5 16.1 -15 16.4 -25 16.3 -35 15.4 -45 15.9 -55 19.1 Grid Box Averages 312 filled boxes Box # Lat.N Lon.E Average 1 85 60 17.6 2 85 180 14.1 3 85 300 18.8 4 75 20 20.1 5 75 60 17.0 6 75 100 16.4 7 75 140 10.7 8 75 180 12.9 9 75 220 15.3 10 75 260 18.4 11 75 300 15.2 12 75 340 15.8 13 65 10 20.3 14 65 30 15.4 15 65 50 15.0 21 65 170 11.4 22 65 190 18.1 23 65 210 18.0 25 65 250 26.1 26 65 270 18.7 27 65 290 18.9 28 65 310 16.4 29 65 330 17.2 30 65 350 17.6 31 55 10 19.5 32 55 30 21.7 38 55 150 10.4 39 55 170 13.4 40 55 190 18.0 41 55 210 15.9 42 55 230 15.2 44 55 270 24.5 45 55 290 19.1 46 55 310 16.9 47 55 330 16.5 48 55 350 17.5 49 45 5 12.1 50 45 15 10.0 51 45 25 13.6 52 45 35 6.5 54 45 55 6.8 62 45 135 9.2 63 45 145 10.4 64 45 155 14.2 65 45 165 17.1 66 45 175 18.8 67 45 185 21.0 68 45 195 19.7 69 45 205 19.6 70 45 215 18.1 71 45 225 15.4 72 45 235 12.2 77 45 285 14.0 78 45 295 13.8 79 45 305 15.7 80 45 315 17.7 81 45 325 17.6 82 45 335 16.4 83 45 345 15.9 84 45 355 15.9 85 35 5 11.1 86 35 15 7.0 87 35 25 2.8 88 35 35 1.7 97 35 125 16.8 98 35 135 20.4 99 35 145 18.9 100 35 155 16.2 101 35 165 13.8 102 35 175 15.3 103 35 185 19.3 104 35 195 15.7 105 35 205 16.2 106 35 215 17.1 107 35 225 13.9 108 35 235 10.2 109 35 245 9.7 112 35 275 15.1 113 35 285 16.2 114 35 295 14.1 115 35 305 11.8 116 35 315 13.0 117 35 325 12.6 118 35 335 13.0 119 35 345 11.0 120 35 355 9.8 124 25 35 6.8 125 25 45 0.9 126 25 55 3.0 127 25 65 7.0 129 25 85 33.4 132 25 115 16.9 133 25 125 13.6 134 25 135 15.1 135 25 145 12.3 136 25 155 11.0 137 25 165 11.1 138 25 175 11.1 139 25 185 11.0 140 25 195 10.2 141 25 205 11.2 142 25 215 15.7 143 25 225 18.3 144 25 235 19.1 145 25 245 9.3 146 25 255 15.5 147 25 265 14.6 148 25 275 16.8 149 25 285 15.4 150 25 295 10.4 151 25 305 10.1 152 25 315 10.3 153 25 325 11.7 154 25 335 12.0 155 25 345 9.1 160 15 35 17.7 161 15 45 14.4 162 15 55 8.4 163 15 65 13.4 164 15 75 20.3 165 15 85 20.4 166 15 95 32.8 167 15 105 23.2 168 15 115 17.4 169 15 125 16.0 170 15 135 18.4 171 15 145 18.6 172 15 155 14.1 173 15 165 12.9 174 15 175 12.6 175 15 185 13.2 176 15 195 13.2 177 15 205 13.1 178 15 215 17.6 179 15 225 22.2 180 15 235 16.7 181 15 245 18.2 182 15 255 24.5 183 15 265 29.8 184 15 275 24.4 185 15 285 15.2 186 15 295 10.3 187 15 305 12.1 188 15 315 14.2 189 15 325 17.4 190 15 335 15.9 191 15 345 18.9 193 5 5 35.4 197 5 45 6.2 198 5 55 7.1 199 5 65 13.7 200 5 75 20.3 201 5 85 25.7 202 5 95 37.3 203 5 105 25.3 204 5 115 23.6 205 5 125 23.3 206 5 135 24.7 207 5 145 22.6 208 5 155 20.4 209 5 165 20.4 210 5 175 20.7 211 5 185 15.1 212 5 195 19.8 213 5 205 14.8 214 5 215 15.2 215 5 225 21.1 216 5 235 19.5 217 5 245 23.5 218 5 255 26.7 219 5 265 29.5 220 5 275 36.3 221 5 285 29.8 223 5 305 15.9 224 5 315 16.8 225 5 325 18.5 226 5 335 25.5 227 5 345 30.3 228 5 355 29.4 229 -5 5 32.3 230 -5 15 25.0 233 -5 45 9.7 234 -5 55 16.3 235 -5 65 22.8 236 -5 75 22.3 237 -5 85 29.3 238 -5 95 26.6 239 -5 105 17.6 240 -5 115 9.0 241 -5 125 12.2 242 -5 135 16.2 243 -5 145 22.6 244 -5 155 22.2 245 -5 165 18.6 246 -5 175 13.6 247 -5 185 10.3 248 -5 195 9.0 249 -5 205 5.5 250 -5 215 7.3 251 -5 225 7.8 252 -5 235 6.4 253 -5 245 10.9 254 -5 255 20.4 255 -5 265 20.5 256 -5 275 24.0 260 -5 315 9.4 261 -5 325 8.7 262 -5 335 9.9 263 -5 345 13.2 264 -5 355 18.7 265 -15 5 25.7 266 -15 15 34.6 268 -15 35 4.1 269 -15 45 5.2 270 -15 55 14.7 271 -15 65 21.1 272 -15 75 20.1 273 -15 85 22.1 274 -15 95 21.5 275 -15 105 10.8 276 -15 115 4.5 277 -15 125 4.0 278 -15 135 5.9 279 -15 145 11.7 280 -15 155 14.2 281 -15 165 19.6 282 -15 175 23.2 283 -15 185 19.6 284 -15 195 13.2 285 -15 205 11.9 286 -15 215 11.1 287 -15 225 7.2 288 -15 235 12.9 289 -15 245 18.3 290 -15 255 22.6 291 -15 265 20.6 292 -15 275 15.9 293 -15 285 13.0 297 -15 325 15.3 298 -15 335 18.1 299 -15 345 22.3 300 -15 355 23.4 301 -25 5 15.6 302 -25 15 13.2 304 -25 35 7.8 305 -25 45 9.7 306 -25 55 12.3 307 -25 65 21.1 308 -25 75 19.7 309 -25 85 18.5 310 -25 95 16.9 311 -25 105 14.8 312 -25 115 7.7 316 -25 155 9.8 317 -25 165 13.7 318 -25 175 16.3 319 -25 185 17.1 320 -25 195 17.1 321 -25 205 25.0 322 -25 215 16.6 323 -25 225 13.9 324 -25 235 17.2 325 -25 245 18.4 328 -25 275 10.8 329 -25 285 8.8 332 -25 315 24.7 333 -25 325 19.2 334 -25 335 17.2 335 -25 345 19.1 336 -25 355 23.9 337 -35 5 20.5 338 -35 15 12.9 339 -35 25 12.9 340 -35 35 13.7 341 -35 45 14.3 342 -35 55 14.1 343 -35 65 15.6 344 -35 75 13.7 345 -35 85 16.1 346 -35 95 18.6 347 -35 105 18.9 348 -35 115 13.2 349 -35 125 15.4 350 -35 135 15.7 351 -35 145 16.5 352 -35 155 14.1 353 -35 165 12.0 354 -35 175 15.1 355 -35 185 16.5 356 -35 195 15.2 357 -35 205 15.5 358 -35 215 13.8 364 -35 275 11.6 365 -35 285 9.7 367 -35 305 15.8 368 -35 315 17.0 369 -35 325 12.6 370 -35 335 18.0 371 -35 345 20.9 372 -35 355 19.0 387 -45 145 9.7 388 -45 155 18.1 389 -45 165 17.7 390 -45 175 13.7 391 -45 185 21.7 401 -45 285 14.0 402 -45 295 18.3 403 -45 305 13.7 417 -55 170 24.3 423 -55 290 12.2 424 -55 310 24.3 425 -55 330 14.4