Altocumulus Average Cloud Amount (%) September, October, November (1954 - 1997) Night, Ship Observations Only Global Average: 16.9 Zonal Averages 17 zones Lat.N Average 85 16.2 75 14.0 65 15.6 55 14.5 45 14.7 35 15.2 25 12.7 15 14.8 5 20.8 -5 16.5 -15 17.3 -25 18.3 -35 17.3 -45 18.2 -55 20.6 -65 15.2 -75 18.7 Grid Box Averages 365 filled boxes Box # Lat.N Lon.E Average 1 85 60 18.5 2 85 180 13.9 3 85 300 16.1 4 75 20 17.9 5 75 60 14.2 6 75 100 15.1 7 75 140 9.0 8 75 180 12.6 9 75 220 13.4 10 75 260 17.7 11 75 300 14.8 12 75 340 14.1 13 65 10 17.8 14 65 30 13.9 15 65 50 13.1 21 65 170 9.0 22 65 190 12.4 23 65 210 15.5 25 65 250 25.1 26 65 270 18.3 27 65 290 17.4 28 65 310 14.3 29 65 330 16.3 30 65 350 15.5 31 55 10 16.9 32 55 30 18.5 38 55 150 9.3 39 55 170 12.3 40 55 190 14.7 41 55 210 13.2 42 55 230 13.2 44 55 270 24.1 45 55 290 19.4 46 55 310 14.4 47 55 330 16.2 48 55 350 16.1 49 45 5 14.4 50 45 15 13.2 51 45 25 14.8 52 45 35 6.6 53 45 45 14.5 54 45 55 7.4 62 45 135 8.2 63 45 145 9.4 64 45 155 12.1 65 45 165 14.1 66 45 175 15.4 67 45 185 16.5 68 45 195 16.5 69 45 205 15.2 70 45 215 16.1 71 45 225 14.8 72 45 235 12.8 77 45 285 13.6 78 45 295 13.5 79 45 305 15.9 80 45 315 16.4 81 45 325 17.6 82 45 335 16.8 83 45 345 15.6 84 45 355 15.8 85 35 5 13.8 86 35 15 10.6 87 35 25 8.0 88 35 35 5.7 96 35 115 11.3 97 35 125 15.7 98 35 135 18.2 99 35 145 17.6 100 35 155 16.5 101 35 165 16.2 102 35 175 16.1 103 35 185 18.5 104 35 195 17.2 105 35 205 17.2 106 35 215 17.4 107 35 225 14.8 108 35 235 10.6 109 35 245 9.0 112 35 275 14.5 113 35 285 15.8 114 35 295 15.5 115 35 305 14.8 116 35 315 14.9 117 35 325 14.7 118 35 335 16.1 119 35 345 12.7 120 35 355 11.3 124 25 35 4.9 125 25 45 4.0 126 25 55 3.0 127 25 65 3.8 128 25 75 6.4 129 25 85 20.6 130 25 95 13.1 131 25 105 18.8 132 25 115 16.7 133 25 125 15.1 134 25 135 15.3 135 25 145 12.2 136 25 155 11.1 137 25 165 10.4 138 25 175 11.1 139 25 185 12.9 140 25 195 12.4 141 25 205 12.1 142 25 215 14.3 143 25 225 18.6 144 25 235 18.1 145 25 245 10.2 146 25 255 12.1 147 25 265 14.3 148 25 275 15.7 149 25 285 14.5 150 25 295 11.6 151 25 305 11.8 152 25 315 12.1 153 25 325 12.3 154 25 335 11.3 155 25 345 9.6 160 15 35 8.0 161 15 45 7.3 162 15 55 6.2 163 15 65 8.6 164 15 75 15.4 165 15 85 15.9 166 15 95 20.6 167 15 105 20.5 168 15 115 15.3 169 15 125 14.4 170 15 135 14.8 171 15 145 13.9 172 15 155 12.0 173 15 165 11.5 174 15 175 12.7 175 15 185 12.9 176 15 195 14.7 177 15 205 13.9 178 15 215 16.9 179 15 225 21.8 180 15 235 20.2 181 15 245 16.2 182 15 255 17.2 183 15 265 21.1 184 15 275 21.5 185 15 285 14.2 186 15 295 10.8 187 15 305 11.9 188 15 315 15.3 189 15 325 16.3 190 15 335 14.7 191 15 345 14.2 193 5 5 29.5 197 5 45 7.5 198 5 55 8.1 199 5 65 13.6 200 5 75 20.5 201 5 85 25.6 202 5 95 36.0 203 5 105 26.2 204 5 115 22.9 205 5 125 20.5 206 5 135 22.1 207 5 145 20.0 208 5 155 19.5 209 5 165 19.6 210 5 175 19.3 211 5 185 17.6 212 5 195 18.3 213 5 205 17.2 214 5 215 16.4 215 5 225 20.8 216 5 235 18.9 217 5 245 21.9 218 5 255 20.2 219 5 265 26.4 220 5 275 33.8 221 5 285 29.2 223 5 305 15.2 224 5 315 16.2 225 5 325 19.1 226 5 335 23.7 227 5 345 22.8 228 5 355 24.1 229 -5 5 32.9 230 -5 15 18.3 232 -5 35 7.7 233 -5 45 8.8 234 -5 55 14.9 235 -5 65 20.7 236 -5 75 21.9 237 -5 85 27.6 238 -5 95 29.0 239 -5 105 21.7 240 -5 115 15.6 241 -5 125 12.8 242 -5 135 15.0 243 -5 145 24.7 244 -5 155 21.3 245 -5 165 21.6 246 -5 175 16.6 247 -5 185 14.2 248 -5 195 9.3 249 -5 205 5.3 250 -5 215 6.4 251 -5 225 6.1 252 -5 235 6.0 253 -5 245 10.6 254 -5 255 16.0 255 -5 265 21.2 256 -5 275 26.2 257 -5 285 22.8 260 -5 315 8.6 261 -5 325 8.3 262 -5 335 10.7 263 -5 345 15.7 264 -5 355 20.8 265 -15 5 27.7 266 -15 15 27.3 268 -15 35 8.3 269 -15 45 6.6 270 -15 55 14.8 271 -15 65 18.0 272 -15 75 20.3 273 -15 85 22.0 274 -15 95 21.3 275 -15 105 11.6 276 -15 115 6.0 277 -15 125 6.3 278 -15 135 7.3 279 -15 145 12.1 280 -15 155 13.3 281 -15 165 18.5 282 -15 175 22.1 283 -15 185 21.6 284 -15 195 18.2 285 -15 205 15.3 286 -15 215 13.8 287 -15 225 9.2 288 -15 235 13.3 289 -15 245 16.9 290 -15 255 21.1 291 -15 265 22.8 292 -15 275 18.4 293 -15 285 13.8 297 -15 325 16.0 298 -15 335 17.8 299 -15 345 26.1 300 -15 355 26.4 301 -25 5 17.4 302 -25 15 12.8 304 -25 35 11.5 305 -25 45 12.3 306 -25 55 13.6 307 -25 65 17.0 308 -25 75 18.8 309 -25 85 20.5 310 -25 95 19.8 311 -25 105 17.2 312 -25 115 8.2 315 -25 145 6.3 316 -25 155 10.6 317 -25 165 15.6 318 -25 175 20.2 319 -25 185 21.0 320 -25 195 21.4 321 -25 205 21.7 322 -25 215 22.0 323 -25 225 17.4 324 -25 235 18.4 325 -25 245 16.9 326 -25 255 23.9 327 -25 265 18.9 328 -25 275 16.4 329 -25 285 11.5 332 -25 315 26.1 333 -25 325 21.3 334 -25 335 17.9 335 -25 345 22.1 336 -25 355 24.4 337 -35 5 21.3 338 -35 15 12.7 339 -35 25 14.2 340 -35 35 15.8 341 -35 45 16.0 342 -35 55 17.1 343 -35 65 17.8 344 -35 75 19.2 345 -35 85 19.5 346 -35 95 20.3 347 -35 105 18.5 348 -35 115 12.7 349 -35 125 15.4 350 -35 135 15.0 351 -35 145 15.8 352 -35 155 15.0 353 -35 165 17.0 354 -35 175 17.8 355 -35 185 19.1 356 -35 195 19.3 357 -35 205 18.0 358 -35 215 17.0 359 -35 225 17.9 360 -35 235 15.7 361 -35 245 15.8 362 -35 255 18.5 363 -35 265 16.2 364 -35 275 14.3 365 -35 285 11.3 367 -35 305 15.3 368 -35 315 16.6 369 -35 325 18.5 370 -35 335 19.1 371 -35 345 20.8 372 -35 355 22.2 378 -45 55 10.0 379 -45 65 21.6 380 -45 75 20.4 381 -45 85 22.4 382 -45 95 25.7 383 -45 105 19.1 384 -45 115 20.8 385 -45 125 15.8 386 -45 135 17.1 387 -45 145 13.3 388 -45 155 17.5 389 -45 165 18.9 390 -45 175 18.0 391 -45 185 20.4 392 -45 195 16.2 393 -45 205 16.6 400 -45 275 10.5 401 -45 285 13.9 402 -45 295 14.3 403 -45 305 17.3 404 -45 315 16.2 405 -45 325 27.1 406 -45 335 23.8 407 -45 345 19.8 408 -45 355 13.7 410 -55 30 28.3 411 -55 50 18.1 412 -55 70 17.1 413 -55 90 19.6 414 -55 110 22.3 415 -55 130 19.8 416 -55 150 14.8 417 -55 170 22.5 421 -55 250 15.1 422 -55 270 18.2 423 -55 290 19.5 424 -55 310 26.5 425 -55 330 25.8 429 -65 50 18.6 430 -65 70 11.9 431 -65 90 16.4 432 -65 110 13.2 433 -65 130 14.8 434 -65 150 17.9 435 -65 170 7.7 441 -65 290 13.1 442 -65 310 25.7 444 -65 350 13.3 449 -75 180 21.1 453 -75 340 14.9