Total Cloud Cover Average Cloud Amount (%) May (1954 - 1997) Day, Ship Observations Only Global Average: 67.6 Zonal Averages 16 zones Lat.N Average 85 73.5 75 79.8 65 78.6 55 80.1 45 78.4 35 67.4 25 57.2 15 56.8 5 66.2 -5 55.8 -15 57.0 -25 61.4 -35 69.1 -45 77.8 -55 82.4 -65 90.8 Grid Box Averages 362 filled boxes Box # Lat.N Lon.E Average 1 85 60 78.6 2 85 180 74.2 3 85 300 65.5 4 75 20 83.0 5 75 60 85.0 6 75 100 72.8 7 75 140 75.7 8 75 180 79.3 9 75 220 84.7 11 75 300 65.6 12 75 340 78.4 13 65 10 72.7 14 65 30 77.0 15 65 50 75.0 20 65 150 66.5 21 65 170 75.8 22 65 190 85.3 23 65 210 76.6 27 65 290 73.4 28 65 310 79.6 29 65 330 81.0 30 65 350 79.6 31 55 10 61.1 32 55 30 54.9 37 55 130 77.0 38 55 150 78.0 39 55 170 83.8 40 55 190 87.4 41 55 210 83.8 42 55 230 80.9 45 55 290 62.0 46 55 310 83.3 47 55 330 82.9 48 55 350 71.5 49 45 5 51.1 50 45 15 47.5 51 45 25 49.7 52 45 35 51.2 53 45 45 50.0 54 45 55 48.4 62 45 135 65.8 63 45 145 73.1 64 45 155 84.6 65 45 165 89.1 66 45 175 89.9 67 45 185 88.8 68 45 195 87.8 69 45 205 86.3 70 45 215 85.3 71 45 225 81.5 72 45 235 70.7 77 45 285 62.2 78 45 295 66.9 79 45 305 74.7 80 45 315 79.0 81 45 325 77.4 82 45 335 77.1 83 45 345 72.0 84 45 355 64.4 85 35 5 47.5 86 35 15 42.0 87 35 25 37.2 88 35 35 34.6 89 35 45 50.5 90 35 55 44.1 96 35 115 52.9 97 35 125 63.5 98 35 135 69.0 99 35 145 71.8 100 35 155 79.7 101 35 165 80.9 102 35 175 77.3 103 35 185 77.3 104 35 195 78.9 105 35 205 77.3 106 35 215 75.6 107 35 225 75.0 108 35 235 66.3 109 35 245 64.3 112 35 275 50.0 113 35 285 57.8 114 35 295 63.8 115 35 305 65.3 116 35 315 63.7 117 35 325 63.3 118 35 335 65.2 119 35 345 60.5 120 35 355 44.1 124 25 35 20.3 125 25 45 25.9 126 25 55 17.0 127 25 65 24.1 128 25 75 28.8 129 25 85 52.1 130 25 95 59.3 131 25 105 63.4 132 25 115 69.0 133 25 125 70.3 134 25 135 67.7 135 25 145 59.9 136 25 155 57.7 137 25 165 55.7 138 25 175 56.1 139 25 185 57.6 140 25 195 56.5 141 25 205 57.4 142 25 215 64.1 143 25 225 73.3 144 25 235 76.2 145 25 245 58.0 146 25 255 37.1 147 25 265 50.8 148 25 275 48.7 149 25 285 53.6 150 25 295 56.8 151 25 305 55.3 152 25 315 52.9 153 25 325 53.3 154 25 335 57.1 155 25 345 41.9 160 15 35 23.2 161 15 45 26.4 162 15 55 33.4 163 15 65 39.8 164 15 75 51.1 165 15 85 57.3 166 15 95 64.4 167 15 105 60.1 168 15 115 53.5 169 15 125 53.0 170 15 135 50.8 171 15 145 50.5 172 15 155 53.3 173 15 165 59.4 174 15 175 57.8 175 15 185 59.3 176 15 195 61.0 177 15 205 60.8 178 15 215 63.8 179 15 225 73.6 180 15 235 76.8 181 15 245 66.0 182 15 255 46.7 183 15 265 56.2 184 15 275 58.4 185 15 285 58.6 186 15 295 55.4 187 15 305 55.8 188 15 315 57.0 189 15 325 62.2 190 15 335 61.8 191 15 345 41.3 193 5 5 72.1 197 5 45 50.5 198 5 55 54.1 199 5 65 57.3 200 5 75 66.2 201 5 85 69.1 202 5 95 75.1 203 5 105 63.9 204 5 115 62.4 205 5 125 59.7 206 5 135 62.9 207 5 145 64.8 208 5 155 64.7 209 5 165 69.9 210 5 175 69.9 211 5 185 65.4 212 5 195 64.8 213 5 205 65.9 214 5 215 68.0 215 5 225 66.5 216 5 235 65.9 217 5 245 68.6 218 5 255 63.3 219 5 265 67.2 220 5 275 74.7 221 5 285 76.2 223 5 305 64.7 224 5 315 68.6 225 5 325 66.3 226 5 335 69.2 227 5 345 69.6 228 5 355 72.1 229 -5 5 60.4 230 -5 15 56.3 232 -5 35 70.5 233 -5 45 54.6 234 -5 55 56.4 235 -5 65 59.3 236 -5 75 62.8 237 -5 85 66.4 238 -5 95 69.0 239 -5 105 65.9 240 -5 115 57.2 241 -5 125 54.7 242 -5 135 63.4 243 -5 145 67.4 244 -5 155 67.2 245 -5 165 61.7 246 -5 175 59.1 247 -5 185 56.2 248 -5 195 53.2 249 -5 205 49.8 250 -5 215 45.6 251 -5 225 44.5 252 -5 235 45.0 253 -5 245 44.2 254 -5 255 44.6 255 -5 265 50.7 256 -5 275 54.8 257 -5 285 70.8 260 -5 315 63.2 261 -5 325 60.0 262 -5 335 53.0 263 -5 345 49.1 264 -5 355 54.9 265 -15 5 63.3 266 -15 15 59.1 268 -15 35 40.5 269 -15 45 44.4 270 -15 55 54.1 271 -15 65 53.8 272 -15 75 55.6 273 -15 85 62.8 274 -15 95 65.4 275 -15 105 58.1 276 -15 115 40.8 277 -15 125 34.5 278 -15 135 54.9 279 -15 145 60.1 280 -15 155 63.1 281 -15 165 65.8 282 -15 175 64.5 283 -15 185 65.7 284 -15 195 63.0 285 -15 205 58.7 286 -15 215 52.6 287 -15 225 48.5 288 -15 235 49.3 289 -15 245 47.5 290 -15 255 50.1 291 -15 265 61.5 292 -15 275 77.2 293 -15 285 74.5 297 -15 325 55.2 298 -15 335 49.9 299 -15 345 49.8 300 -15 355 60.2 301 -25 5 59.5 302 -25 15 47.8 304 -25 35 46.0 305 -25 45 50.4 306 -25 55 55.3 307 -25 65 57.8 308 -25 75 58.5 309 -25 85 61.4 310 -25 95 62.1 311 -25 105 61.1 312 -25 115 46.2 315 -25 145 56.2 316 -25 155 57.8 317 -25 165 61.7 318 -25 175 65.4 319 -25 185 65.5 320 -25 195 68.0 321 -25 205 69.7 322 -25 215 68.3 323 -25 225 65.9 324 -25 235 59.1 325 -25 245 58.8 326 -25 255 62.7 327 -25 265 65.9 328 -25 275 68.0 329 -25 285 76.4 332 -25 315 57.4 333 -25 325 57.4 334 -25 335 61.3 335 -25 345 57.9 336 -25 355 61.7 337 -35 5 69.0 338 -35 15 56.0 339 -35 25 52.8 340 -35 35 54.5 341 -35 45 63.2 342 -35 55 67.5 343 -35 65 68.5 344 -35 75 69.6 345 -35 85 72.5 346 -35 95 72.7 347 -35 105 70.9 348 -35 115 66.5 349 -35 125 69.3 350 -35 135 70.6 351 -35 145 67.8 352 -35 155 63.4 353 -35 165 69.3 354 -35 175 64.7 355 -35 185 67.7 356 -35 195 69.4 357 -35 205 70.7 358 -35 215 74.8 359 -35 225 74.6 360 -35 235 75.2 361 -35 245 72.1 362 -35 255 77.6 363 -35 265 76.5 364 -35 275 74.5 365 -35 285 71.3 367 -35 305 61.6 368 -35 315 67.4 369 -35 325 70.0 370 -35 335 69.6 371 -35 345 70.8 372 -35 355 71.8 373 -45 5 75.5 374 -45 15 79.1 375 -45 25 76.9 376 -45 35 77.3 377 -45 45 83.5 378 -45 55 80.5 379 -45 65 84.8 380 -45 75 75.2 383 -45 105 79.6 384 -45 115 82.6 385 -45 125 80.2 386 -45 135 78.4 387 -45 145 70.5 388 -45 155 75.0 389 -45 165 78.9 390 -45 175 65.0 391 -45 185 75.3 392 -45 195 77.0 393 -45 205 78.5 394 -45 215 82.6 395 -45 225 80.8 396 -45 235 80.5 397 -45 245 81.6 398 -45 255 79.3 399 -45 265 79.3 400 -45 275 80.3 401 -45 285 77.7 402 -45 295 66.9 403 -45 305 68.2 404 -45 315 78.5 405 -45 325 82.7 406 -45 335 78.1 407 -45 345 74.1 408 -45 355 73.5 409 -55 10 78.3 410 -55 30 80.4 411 -55 50 86.7 412 -55 70 86.4 417 -55 170 84.6 419 -55 210 86.3 420 -55 230 85.4 421 -55 250 80.5 422 -55 270 80.1 423 -55 290 75.5 424 -55 310 82.1 425 -55 330 81.2 442 -65 310 90.8