Total Cloud Cover Average Cloud Amount (%) May (1954 - 1997) , Ship Observations Only Global Average: 67.6 Zonal Averages 16 zones Lat.N Average 85 74.2 75 79.2 65 79.1 55 80.9 45 79.1 35 68.3 25 58.3 15 57.0 5 66.4 -5 56.1 -15 57.6 -25 61.8 -35 68.7 -45 77.8 -55 82.3 -65 84.8 Grid Box Averages 373 filled boxes Box # Lat.N Lon.E Average 1 85 60 78.3 2 85 180 74.8 3 85 300 67.7 4 75 20 83.2 5 75 60 85.1 6 75 100 72.8 7 75 140 73.9 8 75 180 78.8 9 75 220 86.2 10 75 260 67.6 11 75 300 65.4 12 75 340 80.2 13 65 10 74.0 14 65 30 78.0 15 65 50 74.1 16 65 70 61.0 20 65 150 68.4 21 65 170 77.6 22 65 190 85.7 23 65 210 76.3 27 65 290 74.3 28 65 310 80.0 29 65 330 81.7 30 65 350 80.6 31 55 10 61.8 32 55 30 53.5 37 55 130 75.6 38 55 150 78.8 39 55 170 85.4 40 55 190 87.6 41 55 210 84.3 42 55 230 81.3 45 55 290 62.2 46 55 310 84.4 47 55 330 83.9 48 55 350 72.6 49 45 5 50.1 50 45 15 47.6 51 45 25 47.3 52 45 35 47.9 53 45 45 51.6 54 45 55 49.1 61 45 125 63.4 62 45 135 64.0 63 45 145 73.4 64 45 155 85.1 65 45 165 90.1 66 45 175 91.0 67 45 185 90.0 68 45 195 88.2 69 45 205 87.3 70 45 215 86.6 71 45 225 83.0 72 45 235 70.6 77 45 285 61.1 78 45 295 66.7 79 45 305 74.5 80 45 315 79.7 81 45 325 79.1 82 45 335 79.2 83 45 345 74.0 84 45 355 65.8 85 35 5 48.3 86 35 15 41.3 87 35 25 36.2 88 35 35 32.9 89 35 45 52.4 90 35 55 44.1 96 35 115 53.3 97 35 125 63.9 98 35 135 67.8 99 35 145 72.4 100 35 155 80.6 101 35 165 82.5 102 35 175 79.4 103 35 185 79.5 104 35 195 79.2 105 35 205 78.7 106 35 215 77.1 107 35 225 76.4 108 35 235 65.9 109 35 245 65.2 112 35 275 48.6 113 35 285 57.3 114 35 295 64.2 115 35 305 66.1 116 35 315 64.4 117 35 325 63.8 118 35 335 67.3 119 35 345 63.7 120 35 355 46.0 124 25 35 18.8 125 25 45 26.8 126 25 55 15.8 127 25 65 24.4 128 25 75 31.5 129 25 85 57.2 130 25 95 58.9 131 25 105 60.9 132 25 115 68.4 133 25 125 70.1 134 25 135 67.9 135 25 145 61.0 136 25 155 59.7 137 25 165 57.0 138 25 175 58.3 139 25 185 58.5 140 25 195 57.9 141 25 205 58.6 142 25 215 65.8 143 25 225 75.9 144 25 235 78.6 145 25 245 59.8 146 25 255 39.4 147 25 265 51.9 148 25 275 47.9 149 25 285 54.3 150 25 295 56.7 151 25 305 55.8 152 25 315 53.0 153 25 325 54.4 154 25 335 59.6 155 25 345 45.3 160 15 35 20.9 161 15 45 26.9 162 15 55 32.8 163 15 65 38.8 164 15 75 51.5 165 15 85 58.2 166 15 95 65.8 167 15 105 59.2 168 15 115 51.7 169 15 125 51.5 170 15 135 49.5 171 15 145 49.5 172 15 155 51.7 173 15 165 58.0 174 15 175 58.2 175 15 185 59.7 176 15 195 62.1 177 15 205 61.7 178 15 215 66.4 179 15 225 76.6 180 15 235 79.4 181 15 245 66.0 182 15 255 48.9 183 15 265 57.6 184 15 275 59.1 185 15 285 59.0 186 15 295 54.5 187 15 305 55.4 188 15 315 57.4 189 15 325 62.3 190 15 335 60.9 191 15 345 39.8 193 5 5 71.2 197 5 45 48.3 198 5 55 51.2 199 5 65 55.8 200 5 75 64.7 201 5 85 68.7 202 5 95 75.5 203 5 105 61.0 204 5 115 60.0 205 5 125 59.7 206 5 135 63.8 207 5 145 67.7 208 5 155 67.5 209 5 165 69.2 210 5 175 68.6 211 5 185 65.7 212 5 195 66.4 213 5 205 67.7 214 5 215 67.3 215 5 225 68.7 216 5 235 65.0 217 5 245 70.8 218 5 255 64.4 219 5 265 68.4 220 5 275 75.4 221 5 285 74.3 223 5 305 65.2 224 5 315 69.8 225 5 325 67.5 226 5 335 69.3 227 5 345 67.7 228 5 355 71.4 229 -5 5 63.1 230 -5 15 51.8 232 -5 35 69.0 233 -5 45 54.4 234 -5 55 55.9 235 -5 65 57.6 236 -5 75 62.7 237 -5 85 65.3 238 -5 95 68.3 239 -5 105 65.2 240 -5 115 54.9 241 -5 125 53.9 242 -5 135 62.3 243 -5 145 69.0 244 -5 155 68.2 245 -5 165 62.0 246 -5 175 56.9 247 -5 185 55.3 248 -5 195 51.4 249 -5 205 49.2 250 -5 215 45.9 251 -5 225 46.1 252 -5 235 45.2 253 -5 245 44.6 254 -5 255 47.7 255 -5 265 54.8 256 -5 275 60.5 257 -5 285 69.3 260 -5 315 62.8 261 -5 325 60.5 262 -5 335 52.1 263 -5 345 48.9 264 -5 355 56.8 265 -15 5 68.2 266 -15 15 55.2 268 -15 35 37.8 269 -15 45 41.6 270 -15 55 55.5 271 -15 65 56.2 272 -15 75 57.8 273 -15 85 63.1 274 -15 95 65.5 275 -15 105 57.4 276 -15 115 39.4 277 -15 125 31.2 278 -15 135 54.4 279 -15 145 59.8 280 -15 155 63.3 281 -15 165 66.3 282 -15 175 63.8 283 -15 185 65.7 284 -15 195 62.5 285 -15 205 57.5 286 -15 215 51.6 287 -15 225 49.2 288 -15 235 49.2 289 -15 245 47.1 290 -15 255 53.0 291 -15 265 65.9 292 -15 275 80.2 293 -15 285 72.7 297 -15 325 54.5 298 -15 335 49.6 299 -15 345 52.2 300 -15 355 65.7 301 -25 5 64.2 302 -25 15 46.0 304 -25 35 43.4 305 -25 45 50.5 306 -25 55 56.1 307 -25 65 60.3 308 -25 75 60.6 309 -25 85 63.9 310 -25 95 64.2 311 -25 105 61.0 312 -25 115 43.9 315 -25 145 56.3 316 -25 155 56.9 317 -25 165 61.7 318 -25 175 65.4 319 -25 185 66.9 320 -25 195 69.3 321 -25 205 69.7 322 -25 215 68.9 323 -25 225 66.0 324 -25 235 58.5 325 -25 245 57.7 326 -25 255 60.0 327 -25 265 64.9 328 -25 275 69.5 329 -25 285 75.1 332 -25 315 57.3 333 -25 325 58.5 334 -25 335 61.3 335 -25 345 58.1 336 -25 355 63.0 337 -35 5 71.6 338 -35 15 54.6 339 -35 25 51.1 340 -35 35 51.8 341 -35 45 63.8 342 -35 55 68.3 343 -35 65 68.6 344 -35 75 71.2 345 -35 85 73.5 346 -35 95 75.0 347 -35 105 71.1 348 -35 115 64.8 349 -35 125 68.8 350 -35 135 70.1 351 -35 145 67.8 352 -35 155 62.8 353 -35 165 69.6 354 -35 175 63.6 355 -35 185 67.7 356 -35 195 68.9 357 -35 205 70.3 358 -35 215 76.5 359 -35 225 74.9 360 -35 235 75.1 361 -35 245 70.9 362 -35 255 76.9 363 -35 265 76.2 364 -35 275 74.0 365 -35 285 68.5 367 -35 305 59.5 368 -35 315 64.3 369 -35 325 70.4 370 -35 335 67.3 371 -35 345 70.0 372 -35 355 70.7 373 -45 5 74.0 374 -45 15 79.8 375 -45 25 78.2 376 -45 35 77.8 377 -45 45 82.8 378 -45 55 81.3 379 -45 65 83.5 380 -45 75 74.3 381 -45 85 78.7 382 -45 95 88.0 383 -45 105 81.6 384 -45 115 81.3 385 -45 125 81.1 386 -45 135 79.1 387 -45 145 68.8 388 -45 155 75.5 389 -45 165 79.6 390 -45 175 63.2 391 -45 185 75.9 392 -45 195 77.7 393 -45 205 79.6 394 -45 215 82.2 395 -45 225 79.5 396 -45 235 79.8 397 -45 245 81.2 398 -45 255 79.6 399 -45 265 76.2 400 -45 275 79.5 401 -45 285 80.1 402 -45 295 66.7 403 -45 305 67.2 404 -45 315 78.2 405 -45 325 80.4 406 -45 335 77.0 407 -45 345 72.1 408 -45 355 74.0 409 -55 10 78.6 410 -55 30 79.6 411 -55 50 86.4 412 -55 70 86.4 417 -55 170 85.1 419 -55 210 86.2 420 -55 230 85.3 421 -55 250 81.4 422 -55 270 80.1 423 -55 290 75.0 424 -55 310 83.6 425 -55 330 78.9 429 -65 50 83.6 433 -65 130 87.5 434 -65 150 70.2 435 -65 170 91.8 441 -65 290 91.2 442 -65 310 90.4 443 -65 330 77.9