Total Cloud Cover Average Cloud Amount (%) September (1954 - 1997) Day, Ship Observations Only Global Average: 67.4 Zonal Averages 16 zones Lat.N Average 85 85.5 75 84.7 65 79.9 55 77.4 45 72.5 35 59.3 25 54.8 15 62.0 5 65.7 -5 57.9 -15 59.3 -25 61.9 -35 69.6 -45 77.1 -55 82.8 -65 83.3 Grid Box Averages 366 filled boxes Box # Lat.N Lon.E Average 1 85 60 86.4 2 85 180 87.2 3 85 300 81.6 4 75 20 84.5 5 75 60 86.3 6 75 100 85.8 7 75 140 85.1 8 75 180 87.2 9 75 220 85.7 10 75 260 79.9 11 75 300 75.6 12 75 340 83.6 13 65 10 77.8 14 65 30 77.3 15 65 50 80.2 16 65 70 86.5 20 65 150 69.7 21 65 170 72.8 22 65 190 83.6 23 65 210 78.1 24 65 230 78.6 25 65 250 82.9 26 65 270 80.4 27 65 290 80.2 28 65 310 76.1 29 65 330 80.3 30 65 350 81.5 31 55 10 69.2 32 55 30 68.1 37 55 130 59.0 38 55 150 69.0 39 55 170 75.5 40 55 190 84.7 41 55 210 81.5 42 55 230 78.1 44 55 270 79.2 45 55 290 76.7 46 55 310 76.4 47 55 330 81.5 48 55 350 75.0 49 45 5 44.7 50 45 15 40.1 51 45 25 40.2 52 45 35 41.4 53 45 45 46.8 54 45 55 36.9 62 45 135 56.1 63 45 145 68.3 64 45 155 77.2 65 45 165 81.2 66 45 175 83.1 67 45 185 83.8 68 45 195 83.1 69 45 205 80.8 70 45 215 79.7 71 45 225 75.7 72 45 235 62.8 77 45 285 58.7 78 45 295 59.5 79 45 305 68.0 80 45 315 73.4 81 45 325 72.3 82 45 335 71.5 83 45 345 69.4 84 45 355 62.0 85 35 5 39.8 86 35 15 35.6 87 35 25 21.8 88 35 35 22.1 90 35 55 36.3 96 35 115 48.6 97 35 125 58.9 98 35 135 64.4 99 35 145 68.5 100 35 155 67.8 101 35 165 66.3 102 35 175 66.8 103 35 185 67.8 104 35 195 65.8 105 35 205 63.5 106 35 215 64.8 107 35 225 68.1 108 35 235 63.8 109 35 245 58.1 112 35 275 56.7 113 35 285 59.6 114 35 295 61.3 115 35 305 59.1 116 35 315 56.0 117 35 325 54.8 118 35 335 56.3 119 35 345 52.5 120 35 355 37.3 124 25 35 13.5 125 25 45 6.1 126 25 55 15.3 127 25 65 44.4 128 25 75 52.8 129 25 85 70.5 130 25 95 70.3 131 25 105 69.1 132 25 115 65.3 133 25 125 61.2 134 25 135 56.8 135 25 145 56.1 136 25 155 54.3 137 25 165 55.1 138 25 175 54.1 139 25 185 54.8 140 25 195 51.1 141 25 205 53.0 142 25 215 58.3 143 25 225 67.9 144 25 235 73.2 145 25 245 50.0 146 25 255 54.0 147 25 265 58.9 148 25 275 59.9 149 25 285 56.5 150 25 295 54.5 151 25 305 52.4 152 25 315 51.2 153 25 325 50.0 154 25 335 51.2 155 25 345 39.6 160 15 35 27.2 161 15 45 29.6 162 15 55 41.5 163 15 65 56.7 164 15 75 65.4 165 15 85 66.4 166 15 95 76.0 167 15 105 70.2 168 15 115 69.8 169 15 125 69.1 170 15 135 68.6 171 15 145 67.1 172 15 155 66.4 173 15 165 63.1 174 15 175 60.7 175 15 185 60.0 176 15 195 57.9 177 15 205 58.8 178 15 215 59.7 179 15 225 64.3 180 15 235 65.9 181 15 245 63.5 182 15 255 67.8 183 15 265 71.5 184 15 275 66.4 185 15 285 59.1 186 15 295 54.0 187 15 305 56.1 188 15 315 57.3 189 15 325 61.3 190 15 335 60.4 191 15 345 56.4 193 5 5 74.4 197 5 45 41.4 198 5 55 45.0 199 5 65 57.3 200 5 75 64.5 201 5 85 69.3 202 5 95 78.2 203 5 105 73.9 204 5 115 73.5 205 5 125 67.1 206 5 135 68.3 207 5 145 66.7 208 5 155 65.8 209 5 165 66.5 210 5 175 64.3 211 5 185 59.5 212 5 195 60.6 213 5 205 60.9 214 5 215 64.4 215 5 225 64.7 216 5 235 65.3 217 5 245 67.7 218 5 255 75.5 219 5 265 79.5 220 5 275 82.4 221 5 285 81.5 223 5 305 53.2 224 5 315 52.2 225 5 325 54.3 226 5 335 64.4 227 5 345 73.9 228 5 355 70.9 229 -5 5 75.6 230 -5 15 80.0 232 -5 35 49.4 233 -5 45 46.7 234 -5 55 56.5 235 -5 65 64.9 236 -5 75 70.8 237 -5 85 74.5 238 -5 95 74.7 239 -5 105 66.8 240 -5 115 48.6 241 -5 125 45.2 242 -5 135 55.5 243 -5 145 64.1 244 -5 155 66.4 245 -5 165 62.5 246 -5 175 58.3 247 -5 185 51.7 248 -5 195 47.4 249 -5 205 45.5 250 -5 215 41.1 251 -5 225 42.2 252 -5 235 38.8 253 -5 245 46.8 254 -5 255 60.0 255 -5 265 71.8 256 -5 275 82.7 257 -5 285 93.2 260 -5 315 42.8 261 -5 325 44.6 262 -5 335 46.0 263 -5 345 56.8 264 -5 355 66.9 265 -15 5 87.8 266 -15 15 75.2 268 -15 35 39.3 269 -15 45 37.9 270 -15 55 52.8 271 -15 65 57.0 272 -15 75 63.4 273 -15 85 65.7 274 -15 95 64.0 275 -15 105 54.6 276 -15 115 27.9 277 -15 125 27.6 278 -15 135 41.2 279 -15 145 45.3 280 -15 155 54.3 281 -15 165 61.4 282 -15 175 65.7 283 -15 185 62.0 284 -15 195 58.1 285 -15 205 54.7 286 -15 215 50.9 287 -15 225 47.5 288 -15 235 46.9 289 -15 245 52.8 290 -15 255 62.4 291 -15 265 69.4 292 -15 275 88.2 293 -15 285 88.2 297 -15 325 53.3 298 -15 335 55.0 299 -15 345 68.0 300 -15 355 86.5 301 -25 5 71.8 302 -25 15 58.1 304 -25 35 49.5 305 -25 45 45.9 306 -25 55 49.8 307 -25 65 57.0 308 -25 75 59.6 309 -25 85 61.7 310 -25 95 63.0 311 -25 105 61.8 312 -25 115 36.7 315 -25 145 32.4 316 -25 155 40.5 317 -25 165 51.9 318 -25 175 59.8 319 -25 185 63.9 320 -25 195 66.3 321 -25 205 67.5 322 -25 215 67.9 323 -25 225 63.7 324 -25 235 60.4 325 -25 245 60.4 326 -25 255 63.8 327 -25 265 72.3 328 -25 275 74.2 329 -25 285 75.2 332 -25 315 68.0 333 -25 325 63.9 334 -25 335 63.7 335 -25 345 62.6 336 -25 355 70.3 337 -35 5 73.6 338 -35 15 56.8 339 -35 25 58.3 340 -35 35 63.8 341 -35 45 65.2 342 -35 55 66.6 343 -35 65 67.0 344 -35 75 71.0 345 -35 85 71.5 346 -35 95 71.5 347 -35 105 72.6 348 -35 115 65.0 349 -35 125 65.9 350 -35 135 67.6 351 -35 145 65.0 352 -35 155 57.7 353 -35 165 64.5 354 -35 175 62.2 355 -35 185 66.3 356 -35 195 69.7 357 -35 205 70.9 358 -35 215 74.1 359 -35 225 75.3 360 -35 235 76.0 361 -35 245 75.7 362 -35 255 77.1 363 -35 265 78.0 364 -35 275 78.5 365 -35 285 67.5 366 -35 295 65.2 367 -35 305 60.1 368 -35 315 70.0 369 -35 325 72.2 370 -35 335 71.6 371 -35 345 71.6 372 -35 355 74.8 375 -45 25 76.6 376 -45 35 79.7 377 -45 45 83.7 378 -45 55 82.5 379 -45 65 81.3 380 -45 75 75.9 382 -45 95 86.6 383 -45 105 77.5 384 -45 115 70.5 385 -45 125 74.3 386 -45 135 76.0 387 -45 145 67.0 388 -45 155 72.7 389 -45 165 76.0 390 -45 175 67.2 391 -45 185 78.2 392 -45 195 80.0 393 -45 205 82.5 394 -45 215 78.8 395 -45 225 83.9 397 -45 245 84.1 400 -45 275 82.0 401 -45 285 77.0 402 -45 295 61.3 403 -45 305 64.2 404 -45 315 77.5 405 -45 325 77.0 407 -45 345 77.7 408 -45 355 74.4 409 -55 10 79.8 411 -55 50 85.6 412 -55 70 81.4 414 -55 110 82.6 416 -55 150 86.3 417 -55 170 83.9 419 -55 210 84.5 420 -55 230 87.5 421 -55 250 86.2 422 -55 270 83.5 423 -55 290 73.0 424 -55 310 79.5 425 -55 330 81.0 432 -65 110 85.6 433 -65 130 75.3 442 -65 310 87.1