Total Cloud Cover Average Cloud Amount (%) September (1954 - 1997) , Ship Observations Only Global Average: 67.7 Zonal Averages 16 zones Lat.N Average 85 86.1 75 85.3 65 80.3 55 77.5 45 72.8 35 59.0 25 54.3 15 62.0 5 66.1 -5 58.5 -15 60.8 -25 63.5 -35 70.0 -45 77.4 -55 81.9 -65 82.6 Grid Box Averages 374 filled boxes Box # Lat.N Lon.E Average 1 85 60 86.7 2 85 180 87.5 3 85 300 83.3 4 75 20 85.4 5 75 60 86.8 6 75 100 85.6 7 75 140 85.5 8 75 180 87.9 9 75 220 86.5 10 75 260 80.8 11 75 300 75.0 12 75 340 84.2 13 65 10 78.4 14 65 30 77.8 15 65 50 80.6 16 65 70 86.7 20 65 150 71.2 21 65 170 74.1 22 65 190 83.8 23 65 210 77.1 24 65 230 78.9 25 65 250 82.7 26 65 270 80.5 27 65 290 79.8 28 65 310 76.2 29 65 330 80.5 30 65 350 82.2 31 55 10 69.7 32 55 30 67.7 37 55 130 57.1 38 55 150 67.2 39 55 170 76.1 40 55 190 85.7 41 55 210 82.0 42 55 230 77.3 44 55 270 79.3 45 55 290 77.0 46 55 310 76.5 47 55 330 81.8 48 55 350 75.3 49 45 5 43.2 50 45 15 37.5 51 45 25 38.1 52 45 35 39.3 53 45 45 50.0 54 45 55 36.6 62 45 135 51.0 63 45 145 67.1 64 45 155 78.2 65 45 165 82.7 66 45 175 84.4 67 45 185 84.9 68 45 195 84.3 69 45 205 81.7 70 45 215 80.4 71 45 225 76.3 72 45 235 62.1 77 45 285 58.9 78 45 295 59.3 79 45 305 67.0 80 45 315 73.3 81 45 325 72.6 82 45 335 72.8 83 45 345 70.5 84 45 355 62.8 85 35 5 40.9 86 35 15 32.5 87 35 25 19.1 88 35 35 20.5 90 35 55 35.0 96 35 115 45.7 97 35 125 58.7 98 35 135 63.7 99 35 145 68.6 100 35 155 67.8 101 35 165 66.2 102 35 175 67.6 103 35 185 68.9 104 35 195 65.6 105 35 205 63.8 106 35 215 65.5 107 35 225 69.0 108 35 235 63.2 109 35 245 59.4 112 35 275 55.0 113 35 285 57.9 114 35 295 59.4 115 35 305 57.1 116 35 315 55.0 117 35 325 54.1 118 35 335 55.9 119 35 345 54.0 120 35 355 37.8 124 25 35 14.4 125 25 45 5.2 126 25 55 14.3 127 25 65 44.8 128 25 75 51.3 129 25 85 71.2 130 25 95 70.4 131 25 105 67.3 132 25 115 61.8 133 25 125 59.6 134 25 135 56.4 135 25 145 55.5 136 25 155 53.4 137 25 165 54.3 138 25 175 53.8 139 25 185 53.5 140 25 195 51.6 141 25 205 53.3 142 25 215 59.3 143 25 225 69.9 144 25 235 74.8 145 25 245 48.1 146 25 255 51.6 147 25 265 56.4 148 25 275 57.7 149 25 285 56.1 150 25 295 53.3 151 25 305 51.2 152 25 315 49.7 153 25 325 49.2 154 25 335 51.3 155 25 345 39.0 160 15 35 32.2 161 15 45 32.2 162 15 55 41.3 163 15 65 55.6 164 15 75 65.3 165 15 85 66.4 166 15 95 76.8 167 15 105 69.4 168 15 115 67.7 169 15 125 67.5 170 15 135 68.0 171 15 145 68.0 172 15 155 66.0 173 15 165 61.8 174 15 175 59.6 175 15 185 59.9 176 15 195 57.7 177 15 205 59.2 178 15 215 63.0 179 15 225 67.2 180 15 235 68.2 181 15 245 64.5 182 15 255 68.3 183 15 265 72.5 184 15 275 66.3 185 15 285 58.3 186 15 295 52.0 187 15 305 54.8 188 15 315 56.8 189 15 325 61.8 190 15 335 59.3 191 15 345 55.2 193 5 5 76.8 197 5 45 40.6 198 5 55 42.4 199 5 65 56.5 200 5 75 63.9 201 5 85 69.2 202 5 95 79.5 203 5 105 72.8 204 5 115 72.0 205 5 125 67.2 206 5 135 69.2 207 5 145 67.6 208 5 155 66.4 209 5 165 65.3 210 5 175 64.8 211 5 185 60.2 212 5 195 61.2 213 5 205 60.7 214 5 215 65.4 215 5 225 62.9 216 5 235 66.8 217 5 245 69.3 218 5 255 77.6 219 5 265 81.1 220 5 275 83.0 221 5 285 79.9 222 5 295 60.7 223 5 305 51.7 224 5 315 52.5 225 5 325 55.1 226 5 335 65.8 227 5 345 75.4 228 5 355 74.9 229 -5 5 79.6 230 -5 15 72.8 232 -5 35 47.3 233 -5 45 47.1 234 -5 55 57.2 235 -5 65 65.0 236 -5 75 70.5 237 -5 85 73.8 238 -5 95 73.8 239 -5 105 64.7 240 -5 115 44.1 241 -5 125 44.5 242 -5 135 52.8 243 -5 145 64.0 244 -5 155 66.4 245 -5 165 62.4 246 -5 175 57.3 247 -5 185 52.1 248 -5 195 46.2 249 -5 205 43.4 250 -5 215 41.8 251 -5 225 41.9 252 -5 235 40.5 253 -5 245 49.0 254 -5 255 65.9 255 -5 265 77.9 256 -5 275 85.5 257 -5 285 92.0 260 -5 315 40.4 261 -5 325 44.3 262 -5 335 47.4 263 -5 345 58.1 264 -5 355 71.8 265 -15 5 90.3 266 -15 15 73.2 268 -15 35 35.3 269 -15 45 33.7 270 -15 55 54.3 271 -15 65 61.8 272 -15 75 66.0 273 -15 85 67.4 274 -15 95 65.1 275 -15 105 54.8 276 -15 115 26.5 277 -15 125 23.2 278 -15 135 36.7 279 -15 145 45.4 280 -15 155 54.9 281 -15 165 61.7 282 -15 175 67.4 283 -15 185 62.5 284 -15 195 58.8 285 -15 205 54.9 286 -15 215 51.7 287 -15 225 47.3 288 -15 235 49.2 289 -15 245 56.9 290 -15 255 67.5 291 -15 265 76.9 292 -15 275 90.2 293 -15 285 87.2 297 -15 325 54.3 298 -15 335 59.5 299 -15 345 72.0 300 -15 355 88.8 301 -25 5 75.2 302 -25 15 56.0 304 -25 35 48.7 305 -25 45 46.7 306 -25 55 52.1 307 -25 65 61.4 308 -25 75 63.1 309 -25 85 66.9 310 -25 95 65.7 311 -25 105 63.1 312 -25 115 35.8 315 -25 145 31.2 316 -25 155 39.3 317 -25 165 52.8 318 -25 175 62.5 319 -25 185 64.8 320 -25 195 66.8 321 -25 205 70.0 322 -25 215 67.2 323 -25 225 62.8 324 -25 235 61.7 325 -25 245 61.8 326 -25 255 65.5 327 -25 265 75.7 328 -25 275 75.7 329 -25 285 75.9 332 -25 315 67.6 333 -25 325 64.8 334 -25 335 65.1 335 -25 345 66.0 336 -25 355 73.7 337 -35 5 75.5 338 -35 15 55.2 339 -35 25 57.4 340 -35 35 64.1 341 -35 45 66.6 342 -35 55 65.8 343 -35 65 67.8 344 -35 75 73.3 345 -35 85 74.0 346 -35 95 74.2 347 -35 105 74.1 348 -35 115 63.9 349 -35 125 64.9 350 -35 135 68.0 351 -35 145 64.7 352 -35 155 56.7 353 -35 165 65.2 354 -35 175 63.0 355 -35 185 67.1 356 -35 195 70.5 357 -35 205 72.7 358 -35 215 74.4 359 -35 225 73.4 360 -35 235 75.6 361 -35 245 73.3 362 -35 255 75.8 363 -35 265 79.1 364 -35 275 79.9 365 -35 285 67.1 366 -35 295 57.6 367 -35 305 58.5 368 -35 315 68.8 369 -35 325 72.0 370 -35 335 73.8 371 -35 345 75.0 372 -35 355 76.3 373 -45 5 69.5 375 -45 25 75.5 376 -45 35 80.1 377 -45 45 83.3 378 -45 55 83.3 379 -45 65 81.9 380 -45 75 77.2 381 -45 85 86.6 382 -45 95 85.7 383 -45 105 75.5 384 -45 115 71.5 385 -45 125 72.9 386 -45 135 74.1 387 -45 145 63.5 388 -45 155 72.2 389 -45 165 76.8 390 -45 175 66.8 391 -45 185 77.8 392 -45 195 79.5 393 -45 205 82.6 394 -45 215 79.2 395 -45 225 84.1 396 -45 235 83.6 397 -45 245 85.3 398 -45 255 79.9 399 -45 265 80.0 400 -45 275 84.4 401 -45 285 74.2 402 -45 295 59.3 403 -45 305 60.0 404 -45 315 73.6 405 -45 325 75.3 406 -45 335 83.7 407 -45 345 79.9 408 -45 355 76.0 409 -55 10 80.4 411 -55 50 85.9 412 -55 70 81.0 414 -55 110 81.9 416 -55 150 86.8 417 -55 170 84.1 419 -55 210 84.7 420 -55 230 88.0 421 -55 250 88.0 422 -55 270 83.5 423 -55 290 72.5 424 -55 310 76.3 425 -55 330 77.7 426 -55 350 74.2 432 -65 110 87.6 433 -65 130 74.2 442 -65 310 85.1