Altocumulus Average Cloud Amount (%) September, October, November (1954 - 1997) Day, Ship Observations Only Global Average: 17.4 Zonal Averages 17 zones Lat.N Average 85 17.3 75 15.9 65 18.2 55 16.8 45 16.5 35 16.6 25 13.5 15 16.0 5 21.5 -5 16.3 -15 16.1 -25 17.3 -35 18.0 -45 18.8 -55 20.5 -65 17.1 -75 17.7 Grid Box Averages 390 filled boxes Box # Lat.N Lon.E Average 1 85 60 17.9 2 85 180 16.6 3 85 300 17.7 4 75 20 20.1 5 75 60 15.2 6 75 100 16.6 7 75 140 13.7 8 75 180 14.2 9 75 220 12.9 10 75 260 18.2 11 75 300 18.0 12 75 340 17.7 13 65 10 21.9 14 65 30 16.3 15 65 50 14.7 16 65 70 19.3 20 65 150 8.5 21 65 170 11.1 22 65 190 13.4 23 65 210 13.2 25 65 250 26.6 26 65 270 20.7 27 65 290 19.6 28 65 310 17.2 29 65 330 19.1 30 65 350 19.4 31 55 10 19.4 32 55 30 21.1 37 55 130 7.4 38 55 150 11.2 39 55 170 13.7 40 55 190 15.4 41 55 210 15.8 42 55 230 16.6 44 55 270 26.3 45 55 290 22.0 46 55 310 17.2 47 55 330 18.9 48 55 350 19.8 49 45 5 14.9 50 45 15 15.3 51 45 25 12.2 52 45 35 9.1 53 45 45 10.3 54 45 55 10.1 61 45 125 6.0 62 45 135 9.7 63 45 145 11.1 64 45 155 14.0 65 45 165 15.2 66 45 175 15.6 67 45 185 16.6 68 45 195 17.4 69 45 205 17.4 70 45 215 18.1 71 45 225 17.5 72 45 235 15.3 77 45 285 14.8 78 45 295 15.2 79 45 305 18.2 80 45 315 19.2 81 45 325 19.4 82 45 335 19.9 83 45 345 18.7 84 45 355 18.2 85 35 5 13.8 86 35 15 12.9 87 35 25 9.1 88 35 35 6.8 89 35 45 5.4 90 35 55 8.8 96 35 115 16.0 97 35 125 17.6 98 35 135 18.0 99 35 145 17.9 100 35 155 17.7 101 35 165 17.2 102 35 175 16.9 103 35 185 17.8 104 35 195 18.6 105 35 205 18.9 106 35 215 18.7 107 35 225 16.6 108 35 235 12.3 109 35 245 8.4 112 35 275 15.6 113 35 285 17.7 114 35 295 18.2 115 35 305 17.9 116 35 315 17.3 117 35 325 17.2 118 35 335 17.4 119 35 345 14.5 120 35 355 13.0 124 25 35 3.9 125 25 45 4.9 126 25 55 2.7 127 25 65 4.2 128 25 75 9.5 129 25 85 13.0 130 25 95 19.1 131 25 105 21.3 132 25 115 18.1 133 25 125 16.7 134 25 135 14.9 135 25 145 12.9 136 25 155 13.0 137 25 165 11.8 138 25 175 12.1 139 25 185 12.3 140 25 195 12.9 141 25 205 12.4 142 25 215 14.5 143 25 225 17.9 144 25 235 16.9 145 25 245 11.0 146 25 255 13.2 147 25 265 16.4 148 25 275 17.1 149 25 285 15.6 150 25 295 14.1 151 25 305 13.7 152 25 315 13.3 153 25 325 12.8 154 25 335 11.8 155 25 345 9.8 156 25 355 12.9 160 15 35 5.0 161 15 45 4.6 162 15 55 6.1 163 15 65 9.7 164 15 75 17.7 165 15 85 16.3 166 15 95 20.5 167 15 105 22.0 168 15 115 18.6 169 15 125 17.8 170 15 135 17.1 171 15 145 15.0 172 15 155 15.0 173 15 165 13.7 174 15 175 14.5 175 15 185 14.4 176 15 195 15.8 177 15 205 15.7 178 15 215 16.8 179 15 225 20.2 180 15 235 20.7 181 15 245 18.0 182 15 255 17.9 183 15 265 21.3 184 15 275 21.4 185 15 285 15.6 186 15 295 12.7 187 15 305 14.4 188 15 315 15.5 189 15 325 16.4 190 15 335 15.5 191 15 345 14.4 193 5 5 25.2 197 5 45 7.5 198 5 55 9.0 199 5 65 14.8 200 5 75 21.9 201 5 85 27.0 202 5 95 35.1 203 5 105 29.9 204 5 115 28.3 205 5 125 22.2 206 5 135 23.4 207 5 145 21.3 208 5 155 22.3 209 5 165 21.4 210 5 175 21.3 211 5 185 19.0 212 5 195 19.1 213 5 205 19.9 214 5 215 18.8 215 5 225 18.4 216 5 235 18.6 217 5 245 21.7 218 5 255 23.0 219 5 265 24.9 220 5 275 31.6 221 5 285 34.9 222 5 295 23.9 223 5 305 16.4 224 5 315 16.4 225 5 325 15.9 226 5 335 22.8 227 5 345 23.2 228 5 355 21.5 229 -5 5 23.7 230 -5 15 32.1 232 -5 35 9.7 233 -5 45 8.8 234 -5 55 13.2 235 -5 65 21.1 236 -5 75 24.9 237 -5 85 31.4 238 -5 95 30.2 239 -5 105 28.0 240 -5 115 18.1 241 -5 125 13.0 242 -5 135 15.7 243 -5 145 25.2 244 -5 155 23.3 245 -5 165 22.6 246 -5 175 19.4 247 -5 185 13.8 248 -5 195 10.8 249 -5 205 7.4 250 -5 215 6.0 251 -5 225 5.5 252 -5 235 6.9 253 -5 245 9.8 254 -5 255 14.7 255 -5 265 16.4 256 -5 275 18.5 257 -5 285 20.7 260 -5 315 8.9 261 -5 325 8.4 262 -5 335 9.5 263 -5 345 15.0 264 -5 355 17.4 265 -15 5 19.5 266 -15 15 30.5 268 -15 35 7.6 269 -15 45 8.2 270 -15 55 12.3 271 -15 65 14.7 272 -15 75 18.0 273 -15 85 19.6 274 -15 95 17.9 275 -15 105 13.8 276 -15 115 6.1 277 -15 125 5.6 278 -15 135 8.5 279 -15 145 10.0 280 -15 155 13.0 281 -15 165 17.8 282 -15 175 21.5 283 -15 185 21.1 284 -15 195 19.9 285 -15 205 17.4 286 -15 215 14.2 287 -15 225 11.4 288 -15 235 12.7 289 -15 245 15.0 290 -15 255 17.8 291 -15 265 21.3 292 -15 275 18.3 293 -15 285 16.0 297 -15 325 16.8 298 -15 335 14.2 299 -15 345 21.0 300 -15 355 22.5 301 -25 5 13.7 302 -25 15 15.7 304 -25 35 12.8 305 -25 45 12.7 306 -25 55 14.1 307 -25 65 16.2 308 -25 75 15.5 309 -25 85 15.7 310 -25 95 17.0 311 -25 105 16.6 312 -25 115 8.3 315 -25 145 7.0 316 -25 155 10.9 317 -25 165 13.3 318 -25 175 17.9 319 -25 185 19.6 320 -25 195 21.7 321 -25 205 21.3 322 -25 215 23.0 323 -25 225 20.8 324 -25 235 18.8 325 -25 245 18.3 326 -25 255 16.3 327 -25 265 18.7 328 -25 275 13.4 329 -25 285 11.4 332 -25 315 24.8 333 -25 325 22.2 334 -25 335 20.1 335 -25 345 21.0 336 -25 355 19.7 337 -35 5 19.9 338 -35 15 13.2 339 -35 25 15.3 340 -35 35 16.1 341 -35 45 16.7 342 -35 55 17.0 343 -35 65 19.5 344 -35 75 18.0 345 -35 85 19.3 346 -35 95 18.4 347 -35 105 17.9 348 -35 115 15.9 349 -35 125 19.1 350 -35 135 18.6 351 -35 145 17.6 352 -35 155 15.5 353 -35 165 18.1 354 -35 175 18.2 355 -35 185 18.4 356 -35 195 18.7 357 -35 205 19.9 358 -35 215 21.6 359 -35 225 17.8 360 -35 235 18.9 361 -35 245 17.0 362 -35 255 18.6 363 -35 265 16.7 364 -35 275 13.6 365 -35 285 11.7 366 -35 295 15.3 367 -35 305 15.9 368 -35 315 18.0 369 -35 325 19.3 370 -35 335 19.3 371 -35 345 21.2 372 -35 355 23.6 373 -45 5 17.8 374 -45 15 18.3 375 -45 25 21.9 376 -45 35 21.2 377 -45 45 19.4 378 -45 55 18.6 379 -45 65 24.7 380 -45 75 19.2 381 -45 85 14.8 382 -45 95 18.5 383 -45 105 23.6 384 -45 115 17.5 385 -45 125 18.9 386 -45 135 22.0 387 -45 145 19.1 388 -45 155 19.2 389 -45 165 20.2 390 -45 175 18.2 391 -45 185 17.1 392 -45 195 20.3 393 -45 205 16.5 394 -45 215 18.3 395 -45 225 15.1 396 -45 235 17.2 397 -45 245 11.1 399 -45 265 13.9 400 -45 275 11.0 401 -45 285 15.1 402 -45 295 15.2 403 -45 305 19.1 404 -45 315 18.6 405 -45 325 24.7 406 -45 335 26.1 407 -45 345 16.9 408 -45 355 24.2 409 -55 10 20.4 410 -55 30 29.5 411 -55 50 20.1 412 -55 70 17.1 413 -55 90 18.9 414 -55 110 21.9 415 -55 130 25.4 416 -55 150 13.3 417 -55 170 21.1 418 -55 190 13.8 419 -55 210 14.0 420 -55 230 17.4 421 -55 250 16.4 422 -55 270 16.1 423 -55 290 21.4 424 -55 310 29.3 425 -55 330 31.4 426 -55 350 22.6 429 -65 50 20.6 430 -65 70 11.7 431 -65 90 25.7 432 -65 110 14.9 433 -65 130 19.7 434 -65 150 14.7 435 -65 170 12.2 436 -65 190 18.3 441 -65 290 14.7 442 -65 310 24.6 444 -65 350 13.6 449 -75 180 20.4 453 -75 340 13.5