Total Cloud Cover Average Cloud Amount (%) September (1954 - 1997) Night, Ship Observations Only Global Average: 67.6 Zonal Averages 16 zones Lat.N Average 85 86.8 75 85.9 65 80.7 55 77.8 45 73.1 35 58.7 25 53.7 15 62.0 5 66.5 -5 59.2 -15 62.3 -25 65.3 -35 70.3 -45 70.8 -55 77.7 -65 89.6 Grid Box Averages 326 filled boxes Box # Lat.N Lon.E Average 1 85 60 87.0 2 85 180 87.7 3 85 300 85.0 4 75 20 86.3 5 75 60 87.3 6 75 100 85.5 7 75 140 86.0 8 75 180 88.6 9 75 220 87.4 10 75 260 81.8 11 75 300 74.3 12 75 340 84.8 13 65 10 79.0 14 65 30 78.2 15 65 50 81.1 16 65 70 86.8 21 65 170 75.3 22 65 190 84.0 23 65 210 76.0 25 65 250 82.4 26 65 270 80.7 27 65 290 79.3 28 65 310 76.3 29 65 330 80.8 30 65 350 82.9 31 55 10 70.2 32 55 30 67.3 38 55 150 65.5 39 55 170 76.8 40 55 190 86.6 41 55 210 82.3 42 55 230 76.5 44 55 270 79.5 45 55 290 77.3 46 55 310 76.6 47 55 330 82.2 48 55 350 75.6 49 45 5 41.7 50 45 15 34.9 51 45 25 36.1 52 45 35 37.1 53 45 45 53.2 54 45 55 36.4 62 45 135 45.9 63 45 145 65.8 64 45 155 79.2 65 45 165 84.3 66 45 175 85.8 67 45 185 86.0 68 45 195 85.4 69 45 205 82.6 70 45 215 81.0 71 45 225 76.9 72 45 235 61.4 77 45 285 59.1 78 45 295 59.0 79 45 305 65.9 80 45 315 73.2 81 45 325 72.8 82 45 335 74.0 83 45 345 71.6 84 45 355 63.6 85 35 5 41.9 86 35 15 29.5 87 35 25 16.4 88 35 35 18.9 97 35 125 58.5 98 35 135 63.0 99 35 145 68.6 100 35 155 67.9 101 35 165 66.1 102 35 175 68.5 103 35 185 69.9 104 35 195 65.3 105 35 205 64.0 106 35 215 66.2 107 35 225 69.9 108 35 235 62.5 109 35 245 60.7 112 35 275 53.3 113 35 285 56.1 114 35 295 57.5 115 35 305 55.2 116 35 315 53.9 117 35 325 53.4 118 35 335 55.5 119 35 345 55.4 120 35 355 38.4 124 25 35 15.2 125 25 45 4.2 126 25 55 13.3 127 25 65 45.2 129 25 85 71.9 132 25 115 58.4 133 25 125 58.0 134 25 135 56.0 135 25 145 54.9 136 25 155 52.5 137 25 165 53.5 138 25 175 53.4 139 25 185 52.3 140 25 195 52.1 141 25 205 53.7 142 25 215 60.3 143 25 225 71.8 144 25 235 76.4 145 25 245 46.3 146 25 255 49.2 147 25 265 54.0 148 25 275 55.5 149 25 285 55.7 150 25 295 52.1 151 25 305 49.9 152 25 315 48.2 153 25 325 48.3 154 25 335 51.3 155 25 345 38.3 160 15 35 37.3 161 15 45 34.9 162 15 55 41.0 163 15 65 54.6 164 15 75 65.2 165 15 85 66.4 166 15 95 77.6 167 15 105 68.7 168 15 115 65.7 169 15 125 66.0 170 15 135 67.5 171 15 145 68.8 172 15 155 65.5 173 15 165 60.5 174 15 175 58.6 175 15 185 59.8 176 15 195 57.4 177 15 205 59.7 178 15 215 66.3 179 15 225 70.1 180 15 235 70.4 181 15 245 65.5 182 15 255 68.9 183 15 265 73.5 184 15 275 66.2 185 15 285 57.6 186 15 295 49.9 187 15 305 53.5 188 15 315 56.3 189 15 325 62.3 190 15 335 58.1 191 15 345 53.9 193 5 5 79.2 197 5 45 39.9 198 5 55 39.8 199 5 65 55.6 200 5 75 63.3 201 5 85 69.2 202 5 95 80.8 203 5 105 71.6 204 5 115 70.6 205 5 125 67.4 206 5 135 70.1 207 5 145 68.5 208 5 155 66.9 209 5 165 64.0 210 5 175 65.3 211 5 185 60.9 212 5 195 61.7 213 5 205 60.5 214 5 215 66.4 215 5 225 61.1 216 5 235 68.3 217 5 245 70.9 218 5 255 79.7 219 5 265 82.7 220 5 275 83.7 221 5 285 78.3 223 5 305 50.2 224 5 315 52.7 225 5 325 55.9 226 5 335 67.2 227 5 345 76.9 228 5 355 78.8 229 -5 5 83.7 230 -5 15 65.5 233 -5 45 47.5 234 -5 55 58.0 235 -5 65 65.0 236 -5 75 70.1 237 -5 85 73.0 238 -5 95 72.9 239 -5 105 62.5 240 -5 115 39.7 241 -5 125 43.9 242 -5 135 50.1 243 -5 145 63.9 244 -5 155 66.4 245 -5 165 62.3 246 -5 175 56.3 247 -5 185 52.4 248 -5 195 45.0 249 -5 205 41.3 250 -5 215 42.5 251 -5 225 41.5 252 -5 235 42.3 253 -5 245 51.2 254 -5 255 71.8 255 -5 265 84.0 256 -5 275 88.4 257 -5 285 87.6 260 -5 315 38.0 261 -5 325 44.0 262 -5 335 48.8 263 -5 345 59.4 264 -5 355 76.6 265 -15 5 92.8 266 -15 15 71.1 268 -15 35 31.3 269 -15 45 29.4 270 -15 55 55.8 271 -15 65 66.6 272 -15 75 68.7 273 -15 85 69.1 274 -15 95 66.2 275 -15 105 55.1 276 -15 115 25.1 277 -15 125 18.8 278 -15 135 32.2 279 -15 145 45.4 280 -15 155 55.5 281 -15 165 61.9 282 -15 175 69.1 283 -15 185 62.9 284 -15 195 59.5 285 -15 205 55.0 286 -15 215 52.5 287 -15 225 47.1 288 -15 235 51.5 289 -15 245 61.1 290 -15 255 72.7 291 -15 265 84.3 292 -15 275 92.3 293 -15 285 86.2 297 -15 325 55.3 298 -15 335 63.9 299 -15 345 75.9 300 -15 355 91.1 301 -25 5 78.7 302 -25 15 54.0 304 -25 35 47.9 305 -25 45 47.5 306 -25 55 54.5 307 -25 65 65.8 308 -25 75 66.7 309 -25 85 72.0 310 -25 95 68.4 311 -25 105 64.3 312 -25 115 34.9 315 -25 145 27.0 316 -25 155 38.0 317 -25 165 53.7 318 -25 175 65.2 319 -25 185 65.7 320 -25 195 67.2 321 -25 205 72.4 322 -25 215 66.4 323 -25 225 61.9 324 -25 235 63.0 325 -25 245 63.2 326 -25 255 71.2 327 -25 265 79.1 328 -25 275 77.3 329 -25 285 76.7 332 -25 315 67.2 333 -25 325 65.7 334 -25 335 66.5 335 -25 345 69.4 336 -25 355 77.1 337 -35 5 77.5 338 -35 15 53.6 339 -35 25 56.5 340 -35 35 64.3 341 -35 45 68.0 342 -35 55 64.9 343 -35 65 68.7 344 -35 75 75.6 345 -35 85 76.6 346 -35 95 76.8 347 -35 105 75.6 348 -35 115 62.7 349 -35 125 63.9 350 -35 135 68.4 351 -35 145 64.4 352 -35 155 55.8 353 -35 165 66.0 354 -35 175 63.8 355 -35 185 67.9 356 -35 195 71.3 357 -35 205 74.5 358 -35 215 74.7 359 -35 225 71.4 360 -35 235 74.0 363 -35 265 80.9 364 -35 275 81.3 365 -35 285 66.7 367 -35 305 56.8 368 -35 315 67.6 369 -35 325 71.8 370 -35 335 76.0 371 -35 345 78.3 372 -35 355 77.8 387 -45 145 60.1 388 -45 155 71.6 389 -45 165 77.7 390 -45 175 66.5 391 -45 185 77.4 392 -45 195 77.4 400 -45 275 86.8 401 -45 285 71.5 402 -45 295 57.3 403 -45 305 55.9 404 -45 315 69.8 417 -55 170 84.3 422 -55 270 83.6 423 -55 290 72.0 424 -55 310 73.2 425 -55 330 74.4 432 -65 110 89.6