Total Cloud Cover Average Cloud Amount (%) March, April, May (1954 - 1997) Day, Ship Observations Only Global Average: 66.9 Zonal Averages 17 zones Lat.N Average 85 61.8 75 69.2 65 77.2 55 79.2 45 77.6 35 68.8 25 57.5 15 52.3 5 62.2 -5 57.8 -15 57.4 -25 61.1 -35 68.4 -45 78.5 -55 84.6 -65 88.3 -75 81.6 Grid Box Averages 400 filled boxes Box # Lat.N Lon.E Average 1 85 60 65.2 2 85 180 60.3 3 85 300 59.1 4 75 20 81.7 5 75 60 76.8 6 75 100 51.8 7 75 140 57.7 8 75 180 62.6 9 75 220 71.0 10 75 260 68.6 11 75 300 63.6 12 75 340 77.5 13 65 10 75.3 14 65 30 74.9 15 65 50 69.1 16 65 70 57.2 20 65 150 66.1 21 65 170 74.2 22 65 190 79.3 23 65 210 74.2 26 65 270 72.8 27 65 290 72.1 28 65 310 77.7 29 65 330 82.0 30 65 350 80.8 31 55 10 66.4 32 55 30 60.0 37 55 130 74.6 38 55 150 74.8 39 55 170 81.1 40 55 190 85.0 41 55 210 82.6 42 55 230 79.7 44 55 270 67.9 45 55 290 68.5 46 55 310 83.9 47 55 330 82.8 48 55 350 74.4 49 45 5 54.0 50 45 15 52.3 51 45 25 59.4 52 45 35 61.0 53 45 45 60.2 54 45 55 56.4 61 45 125 58.5 62 45 135 58.9 63 45 145 69.0 64 45 155 82.3 65 45 165 85.8 66 45 175 85.8 67 45 185 85.1 68 45 195 84.9 69 45 205 84.1 70 45 215 83.4 71 45 225 80.4 72 45 235 72.3 77 45 285 61.1 78 45 295 67.3 79 45 305 76.2 80 45 315 80.4 81 45 325 78.5 82 45 335 77.3 83 45 345 73.2 84 45 355 66.8 85 35 5 51.8 86 35 15 49.1 87 35 25 46.2 88 35 35 43.9 89 35 45 61.2 90 35 55 55.1 96 35 115 50.5 97 35 125 62.4 98 35 135 67.6 99 35 145 72.3 100 35 155 78.4 101 35 165 79.1 102 35 175 76.8 103 35 185 76.8 104 35 195 77.7 105 35 205 77.0 106 35 215 76.3 107 35 225 75.3 108 35 235 65.3 109 35 245 57.4 112 35 275 50.5 113 35 285 59.8 114 35 295 68.4 115 35 305 69.3 116 35 315 67.5 117 35 325 66.7 118 35 335 68.2 119 35 345 62.4 120 35 355 47.8 124 25 35 22.4 125 25 45 40.1 126 25 55 28.1 127 25 65 23.8 128 25 75 25.4 129 25 85 43.1 130 25 95 46.2 131 25 105 79.0 132 25 115 73.0 133 25 125 71.0 134 25 135 65.1 135 25 145 58.4 136 25 155 59.4 137 25 165 58.3 138 25 175 57.7 139 25 185 59.0 140 25 195 58.9 141 25 205 60.4 142 25 215 66.8 143 25 225 72.6 144 25 235 73.3 145 25 245 52.9 146 25 255 38.4 147 25 265 54.9 148 25 275 49.5 149 25 285 52.5 150 25 295 53.9 151 25 305 54.0 152 25 315 54.5 153 25 325 55.3 154 25 335 55.9 155 25 345 40.0 156 25 355 49.1 160 15 35 24.0 161 15 45 28.9 162 15 55 30.1 163 15 65 29.7 164 15 75 37.1 165 15 85 43.0 166 15 95 43.5 167 15 105 60.5 168 15 115 48.6 169 15 125 50.3 170 15 135 50.9 171 15 145 51.1 172 15 155 52.8 173 15 165 56.3 174 15 175 54.4 175 15 185 56.3 176 15 195 59.3 177 15 205 59.3 178 15 215 64.8 179 15 225 72.0 180 15 235 74.1 181 15 245 62.2 182 15 255 40.7 183 15 265 41.5 184 15 275 48.3 185 15 285 52.3 186 15 295 49.7 187 15 305 51.8 188 15 315 53.4 189 15 325 58.6 190 15 335 55.6 191 15 345 34.2 193 5 5 69.5 197 5 45 43.8 198 5 55 45.0 199 5 65 46.2 200 5 75 53.9 201 5 85 62.0 202 5 95 68.3 203 5 105 59.5 204 5 115 57.6 205 5 125 58.8 206 5 135 63.0 207 5 145 65.4 208 5 155 66.9 209 5 165 68.9 210 5 175 65.9 211 5 185 65.5 212 5 195 64.9 213 5 205 66.4 214 5 215 67.4 215 5 225 65.7 216 5 235 65.2 217 5 245 62.4 218 5 255 55.5 219 5 265 56.7 220 5 275 61.3 221 5 285 66.6 222 5 295 57.5 223 5 305 61.4 224 5 315 68.5 225 5 325 67.9 226 5 335 65.5 227 5 345 60.6 228 5 355 67.8 229 -5 5 62.5 230 -5 15 63.3 232 -5 35 62.6 233 -5 45 51.2 234 -5 55 52.3 235 -5 65 56.4 236 -5 75 60.4 237 -5 85 64.3 238 -5 95 67.8 239 -5 105 68.7 240 -5 115 63.2 241 -5 125 58.6 242 -5 135 67.2 243 -5 145 71.0 244 -5 155 68.8 245 -5 165 66.5 246 -5 175 63.5 247 -5 185 59.9 248 -5 195 56.0 249 -5 205 52.6 250 -5 215 50.2 251 -5 225 48.5 252 -5 235 48.6 253 -5 245 51.5 254 -5 255 51.9 255 -5 265 55.5 256 -5 275 52.1 257 -5 285 60.7 260 -5 315 69.2 261 -5 325 61.4 262 -5 335 55.5 263 -5 345 50.9 264 -5 355 54.6 265 -15 5 66.1 266 -15 15 64.8 268 -15 35 47.3 269 -15 45 52.3 270 -15 55 55.5 271 -15 65 55.2 272 -15 75 57.3 273 -15 85 61.6 274 -15 95 64.2 275 -15 105 57.5 276 -15 115 43.0 277 -15 125 44.8 278 -15 135 61.9 279 -15 145 63.8 280 -15 155 64.0 281 -15 165 65.2 282 -15 175 66.8 283 -15 185 67.5 284 -15 195 63.3 285 -15 205 59.7 286 -15 215 54.4 287 -15 225 49.4 288 -15 235 48.9 289 -15 245 48.9 290 -15 255 51.6 291 -15 265 57.6 292 -15 275 67.3 293 -15 285 64.1 297 -15 325 55.4 298 -15 335 48.7 299 -15 345 47.4 300 -15 355 58.5 301 -25 5 63.1 302 -25 15 53.0 304 -25 35 49.6 305 -25 45 53.0 306 -25 55 57.7 307 -25 65 58.2 308 -25 75 59.5 309 -25 85 61.2 310 -25 95 63.5 311 -25 105 62.7 312 -25 115 44.5 315 -25 145 59.0 316 -25 155 57.7 317 -25 165 60.4 318 -25 175 64.8 319 -25 185 66.8 320 -25 195 68.7 321 -25 205 68.6 322 -25 215 67.3 323 -25 225 63.9 324 -25 235 58.3 325 -25 245 55.8 326 -25 255 56.3 327 -25 265 62.8 328 -25 275 66.5 329 -25 285 76.3 332 -25 315 58.4 333 -25 325 58.1 334 -25 335 59.9 335 -25 345 56.6 336 -25 355 59.5 337 -35 5 69.2 338 -35 15 53.7 339 -35 25 55.0 340 -35 35 57.3 341 -35 45 63.6 342 -35 55 67.7 343 -35 65 69.7 344 -35 75 69.8 345 -35 85 71.7 346 -35 95 73.8 347 -35 105 72.8 348 -35 115 63.4 349 -35 125 70.5 350 -35 135 69.9 351 -35 145 64.5 352 -35 155 61.0 353 -35 165 67.2 354 -35 175 62.3 355 -35 185 67.4 356 -35 195 70.5 357 -35 205 72.3 358 -35 215 74.2 359 -35 225 74.9 360 -35 235 70.7 361 -35 245 72.9 362 -35 255 74.1 363 -35 265 74.7 364 -35 275 74.5 365 -35 285 69.0 366 -35 295 57.4 367 -35 305 57.5 368 -35 315 64.2 369 -35 325 68.7 370 -35 335 69.6 371 -35 345 69.7 372 -35 355 69.3 373 -45 5 79.9 374 -45 15 80.9 375 -45 25 80.4 376 -45 35 81.6 377 -45 45 81.0 378 -45 55 80.6 379 -45 65 80.5 380 -45 75 80.0 381 -45 85 83.0 382 -45 95 81.0 383 -45 105 84.5 384 -45 115 83.5 385 -45 125 80.4 386 -45 135 78.4 387 -45 145 70.3 388 -45 155 73.3 389 -45 165 78.5 390 -45 175 64.0 391 -45 185 74.5 392 -45 195 78.7 393 -45 205 80.3 394 -45 215 80.5 395 -45 225 82.8 396 -45 235 82.8 397 -45 245 82.3 398 -45 255 80.6 399 -45 265 80.0 400 -45 275 81.3 401 -45 285 80.6 402 -45 295 60.9 403 -45 305 64.7 404 -45 315 74.7 405 -45 325 78.1 406 -45 335 76.9 407 -45 345 77.5 408 -45 355 77.4 409 -55 10 85.7 410 -55 30 85.6 411 -55 50 85.4 412 -55 70 85.7 413 -55 90 85.7 414 -55 110 86.9 415 -55 130 84.7 416 -55 150 84.3 417 -55 170 83.9 418 -55 190 85.7 419 -55 210 86.7 420 -55 230 85.7 421 -55 250 86.3 422 -55 270 82.8 423 -55 290 76.1 424 -55 310 80.8 425 -55 330 82.4 426 -55 350 87.5 427 -65 10 84.3 428 -65 30 87.6 429 -65 50 84.3 430 -65 70 86.2 431 -65 90 90.0 432 -65 110 89.3 433 -65 130 86.8 434 -65 150 86.5 435 -65 170 89.5 436 -65 190 90.0 437 -65 210 92.2 438 -65 230 88.3 439 -65 250 89.2 440 -65 270 90.2 441 -65 290 84.2 442 -65 310 90.0 443 -65 330 90.0 444 -65 350 88.5 449 -75 180 86.1 450 -75 220 86.4 451 -75 260 80.8 452 -75 300 77.2 453 -75 340 72.9