Altocumulus Average Cloud Amount (%) September, October, November (1954 - 1997) , Ship Observations Only Global Average: 17.1 Zonal Averages 17 zones Lat.N Average 85 16.8 75 14.9 65 16.9 55 15.6 45 15.6 35 15.9 25 13.1 15 15.4 5 21.2 -5 16.4 -15 16.7 -25 17.8 -35 17.6 -45 18.0 -55 20.2 -65 15.7 -75 18.2 Grid Box Averages 394 filled boxes Box # Lat.N Lon.E Average 1 85 60 18.2 2 85 180 15.3 3 85 300 16.9 4 75 20 19.0 5 75 60 14.7 6 75 100 15.8 7 75 140 11.3 8 75 180 13.4 9 75 220 13.1 10 75 260 17.9 11 75 300 16.4 12 75 340 15.9 13 65 10 19.9 14 65 30 15.1 15 65 50 13.9 16 65 70 17.7 20 65 150 8.6 21 65 170 10.1 22 65 190 12.9 23 65 210 14.4 24 65 230 15.5 25 65 250 25.9 26 65 270 19.5 27 65 290 18.5 28 65 310 15.8 29 65 330 17.7 30 65 350 17.5 31 55 10 18.1 32 55 30 19.8 37 55 130 9.6 38 55 150 10.2 39 55 170 13.0 40 55 190 15.1 41 55 210 14.5 42 55 230 14.9 44 55 270 25.2 45 55 290 20.7 46 55 310 15.8 47 55 330 17.6 48 55 350 17.9 49 45 5 14.6 50 45 15 14.3 51 45 25 13.5 52 45 35 7.8 53 45 45 12.4 54 45 55 8.7 61 45 125 6.4 62 45 135 8.9 63 45 145 10.2 64 45 155 13.0 65 45 165 14.6 66 45 175 15.5 67 45 185 16.5 68 45 195 16.9 69 45 205 16.3 70 45 215 17.1 71 45 225 16.1 72 45 235 14.1 77 45 285 14.2 78 45 295 14.4 79 45 305 17.0 80 45 315 17.8 81 45 325 18.5 82 45 335 18.3 83 45 345 17.1 84 45 355 17.0 85 35 5 13.8 86 35 15 11.7 87 35 25 8.6 88 35 35 6.2 89 35 45 6.7 90 35 55 5.2 96 35 115 13.7 97 35 125 16.6 98 35 135 18.1 99 35 145 17.7 100 35 155 17.1 101 35 165 16.7 102 35 175 16.5 103 35 185 18.1 104 35 195 17.9 105 35 205 18.1 106 35 215 18.0 107 35 225 15.7 108 35 235 11.5 109 35 245 8.7 112 35 275 15.1 113 35 285 16.8 114 35 295 16.8 115 35 305 16.4 116 35 315 16.1 117 35 325 15.9 118 35 335 16.7 119 35 345 13.6 120 35 355 12.2 124 25 35 4.4 125 25 45 4.4 126 25 55 2.9 127 25 65 4.0 128 25 75 7.9 129 25 85 16.8 130 25 95 16.1 131 25 105 20.1 132 25 115 17.4 133 25 125 15.9 134 25 135 15.1 135 25 145 12.5 136 25 155 12.0 137 25 165 11.1 138 25 175 11.6 139 25 185 12.6 140 25 195 12.6 141 25 205 12.2 142 25 215 14.4 143 25 225 18.3 144 25 235 17.5 145 25 245 10.6 146 25 255 12.6 147 25 265 15.4 148 25 275 16.4 149 25 285 15.1 150 25 295 12.9 151 25 305 12.7 152 25 315 12.7 153 25 325 12.6 154 25 335 11.5 155 25 345 9.7 156 25 355 11.2 160 15 35 6.5 161 15 45 5.9 162 15 55 6.2 163 15 65 9.1 164 15 75 16.6 165 15 85 16.1 166 15 95 20.6 167 15 105 21.2 168 15 115 16.9 169 15 125 16.1 170 15 135 15.9 171 15 145 14.4 172 15 155 13.5 173 15 165 12.6 174 15 175 13.6 175 15 185 13.7 176 15 195 15.2 177 15 205 14.8 178 15 215 16.8 179 15 225 21.0 180 15 235 20.5 181 15 245 17.1 182 15 255 17.6 183 15 265 21.2 184 15 275 21.4 185 15 285 14.9 186 15 295 11.8 187 15 305 13.2 188 15 315 15.4 189 15 325 16.3 190 15 335 15.1 191 15 345 14.3 193 5 5 27.4 197 5 45 7.5 198 5 55 8.6 199 5 65 14.2 200 5 75 21.2 201 5 85 26.3 202 5 95 35.6 203 5 105 28.0 204 5 115 25.6 205 5 125 21.4 206 5 135 22.8 207 5 145 20.6 208 5 155 20.9 209 5 165 20.5 210 5 175 20.3 211 5 185 18.3 212 5 195 18.7 213 5 205 18.5 214 5 215 17.6 215 5 225 19.6 216 5 235 18.8 217 5 245 21.8 218 5 255 21.6 219 5 265 25.6 220 5 275 32.7 221 5 285 32.1 222 5 295 22.4 223 5 305 15.8 224 5 315 16.3 225 5 325 17.5 226 5 335 23.3 227 5 345 23.0 228 5 355 22.8 229 -5 5 28.3 230 -5 15 25.2 232 -5 35 8.7 233 -5 45 8.8 234 -5 55 14.0 235 -5 65 20.9 236 -5 75 23.4 237 -5 85 29.5 238 -5 95 29.6 239 -5 105 24.9 240 -5 115 16.8 241 -5 125 12.9 242 -5 135 15.3 243 -5 145 24.9 244 -5 155 22.3 245 -5 165 22.1 246 -5 175 18.0 247 -5 185 14.0 248 -5 195 10.1 249 -5 205 6.3 250 -5 215 6.2 251 -5 225 5.8 252 -5 235 6.4 253 -5 245 10.2 254 -5 255 15.3 255 -5 265 18.8 256 -5 275 22.4 257 -5 285 21.8 260 -5 315 8.7 261 -5 325 8.4 262 -5 335 10.1 263 -5 345 15.4 264 -5 355 19.1 265 -15 5 23.6 266 -15 15 28.9 268 -15 35 8.0 269 -15 45 7.4 270 -15 55 13.6 271 -15 65 16.3 272 -15 75 19.2 273 -15 85 20.8 274 -15 95 19.6 275 -15 105 12.7 276 -15 115 6.1 277 -15 125 5.9 278 -15 135 7.9 279 -15 145 11.0 280 -15 155 13.2 281 -15 165 18.1 282 -15 175 21.8 283 -15 185 21.3 284 -15 195 19.0 285 -15 205 16.3 286 -15 215 14.0 287 -15 225 10.3 288 -15 235 13.0 289 -15 245 15.9 290 -15 255 19.4 291 -15 265 22.1 292 -15 275 18.4 293 -15 285 14.9 297 -15 325 16.4 298 -15 335 16.0 299 -15 345 23.6 300 -15 355 24.4 301 -25 5 15.5 302 -25 15 14.3 304 -25 35 12.1 305 -25 45 12.5 306 -25 55 13.8 307 -25 65 16.6 308 -25 75 17.1 309 -25 85 18.1 310 -25 95 18.4 311 -25 105 16.9 312 -25 115 8.3 315 -25 145 6.7 316 -25 155 10.8 317 -25 165 14.4 318 -25 175 19.1 319 -25 185 20.3 320 -25 195 21.5 321 -25 205 21.5 322 -25 215 22.5 323 -25 225 19.1 324 -25 235 18.6 325 -25 245 17.6 326 -25 255 20.1 327 -25 265 18.8 328 -25 275 14.9 329 -25 285 11.5 332 -25 315 25.5 333 -25 325 21.8 334 -25 335 19.0 335 -25 345 21.6 336 -25 355 22.1 337 -35 5 20.6 338 -35 15 13.0 339 -35 25 14.7 340 -35 35 16.0 341 -35 45 16.3 342 -35 55 17.0 343 -35 65 18.7 344 -35 75 18.6 345 -35 85 19.4 346 -35 95 19.3 347 -35 105 18.2 348 -35 115 14.3 349 -35 125 17.3 350 -35 135 16.8 351 -35 145 16.7 352 -35 155 15.3 353 -35 165 17.5 354 -35 175 18.0 355 -35 185 18.7 356 -35 195 19.0 357 -35 205 18.9 358 -35 215 19.3 359 -35 225 17.9 360 -35 235 17.3 361 -35 245 16.4 362 -35 255 18.6 363 -35 265 16.4 364 -35 275 14.0 365 -35 285 11.5 366 -35 295 12.9 367 -35 305 15.6 368 -35 315 17.3 369 -35 325 18.9 370 -35 335 19.2 371 -35 345 21.0 372 -35 355 22.9 373 -45 5 15.9 374 -45 15 16.3 375 -45 25 23.3 376 -45 35 22.9 377 -45 45 16.2 378 -45 55 14.3 379 -45 65 23.1 380 -45 75 19.8 381 -45 85 18.6 382 -45 95 22.1 383 -45 105 21.4 384 -45 115 19.2 385 -45 125 17.3 386 -45 135 19.6 387 -45 145 16.2 388 -45 155 18.4 389 -45 165 19.6 390 -45 175 18.1 391 -45 185 18.8 392 -45 195 18.2 393 -45 205 16.6 394 -45 215 17.7 395 -45 225 14.5 396 -45 235 15.9 397 -45 245 9.4 398 -45 255 14.2 399 -45 265 13.4 400 -45 275 10.7 401 -45 285 14.5 402 -45 295 14.7 403 -45 305 18.2 404 -45 315 17.4 405 -45 325 25.9 406 -45 335 24.9 407 -45 345 18.3 408 -45 355 18.9 409 -55 10 20.1 410 -55 30 28.9 411 -55 50 19.1 412 -55 70 17.1 413 -55 90 19.2 414 -55 110 22.1 415 -55 130 22.6 416 -55 150 14.1 417 -55 170 21.8 418 -55 190 13.5 419 -55 210 16.5 420 -55 230 17.3 421 -55 250 15.7 422 -55 270 17.1 423 -55 290 20.5 424 -55 310 27.9 425 -55 330 28.6 426 -55 350 22.1 427 -65 10 10.1 429 -65 50 19.6 430 -65 70 11.8 431 -65 90 21.1 432 -65 110 14.1 433 -65 130 17.3 434 -65 150 16.3 435 -65 170 10.0 436 -65 190 20.1 441 -65 290 13.9 442 -65 310 25.1 443 -65 330 14.0 444 -65 350 13.4 449 -75 180 20.8 453 -75 340 14.2