Total Cloud Cover Average Cloud Amount (%) March, April, May (1954 - 1997) , Ship Observations Only Global Average: 67.2 Zonal Averages 17 zones Lat.N Average 85 61.9 75 69.6 65 77.7 55 79.8 45 78.0 35 69.2 25 58.4 15 52.7 5 62.1 -5 58.0 -15 58.0 -25 61.8 -35 68.5 -45 78.8 -55 84.9 -65 88.2 -75 82.5 Grid Box Averages 400 filled boxes Box # Lat.N Lon.E Average 1 85 60 65.1 2 85 180 60.7 3 85 300 59.4 4 75 20 82.2 5 75 60 77.7 6 75 100 53.6 7 75 140 56.0 8 75 180 62.7 9 75 220 72.0 10 75 260 67.7 11 75 300 63.9 12 75 340 78.9 13 65 10 75.7 14 65 30 76.4 15 65 50 69.3 16 65 70 59.1 20 65 150 68.4 21 65 170 76.1 22 65 190 80.2 23 65 210 74.1 26 65 270 72.9 27 65 290 72.0 28 65 310 78.4 29 65 330 82.3 30 65 350 81.3 31 55 10 66.5 32 55 30 58.7 37 55 130 74.0 38 55 150 75.2 39 55 170 82.3 40 55 190 85.6 41 55 210 83.0 42 55 230 79.7 44 55 270 69.2 45 55 290 68.1 46 55 310 84.7 47 55 330 83.5 48 55 350 74.5 49 45 5 52.9 50 45 15 51.1 51 45 25 56.2 52 45 35 58.2 53 45 45 58.8 54 45 55 52.0 61 45 125 57.5 62 45 135 55.5 63 45 145 68.4 64 45 155 83.0 65 45 165 86.9 66 45 175 87.0 67 45 185 86.0 68 45 195 85.5 69 45 205 85.4 70 45 215 84.4 71 45 225 81.0 72 45 235 72.2 77 45 285 60.6 78 45 295 67.0 79 45 305 76.2 80 45 315 80.7 81 45 325 79.3 82 45 335 78.7 83 45 345 74.6 84 45 355 67.6 85 35 5 52.1 86 35 15 47.7 87 35 25 44.0 88 35 35 41.7 89 35 45 63.2 90 35 55 50.8 96 35 115 47.0 97 35 125 61.7 98 35 135 66.1 99 35 145 71.9 100 35 155 79.2 101 35 165 80.4 102 35 175 78.5 103 35 185 78.7 104 35 195 78.5 105 35 205 78.3 106 35 215 77.3 107 35 225 76.3 108 35 235 64.9 109 35 245 57.1 112 35 275 49.3 113 35 285 58.5 114 35 295 68.3 115 35 305 69.4 116 35 315 67.7 117 35 325 67.0 118 35 335 68.8 119 35 345 64.3 120 35 355 48.0 124 25 35 20.9 125 25 45 38.5 126 25 55 26.8 127 25 65 23.6 128 25 75 27.2 129 25 85 44.8 130 25 95 49.4 131 25 105 76.7 132 25 115 71.9 133 25 125 70.8 134 25 135 65.3 135 25 145 59.3 136 25 155 60.5 137 25 165 60.0 138 25 175 59.8 139 25 185 60.6 140 25 195 60.1 141 25 205 61.6 142 25 215 68.6 143 25 225 74.9 144 25 235 74.9 145 25 245 53.4 146 25 255 39.1 147 25 265 55.1 148 25 275 49.0 149 25 285 52.6 150 25 295 53.5 151 25 305 53.8 152 25 315 54.8 153 25 325 56.2 154 25 335 57.6 155 25 345 42.6 156 25 355 49.7 160 15 35 22.4 161 15 45 28.4 162 15 55 29.6 163 15 65 28.9 164 15 75 37.7 165 15 85 44.5 166 15 95 44.8 167 15 105 58.5 168 15 115 46.7 169 15 125 49.3 170 15 135 50.3 171 15 145 51.1 172 15 155 52.3 173 15 165 56.1 174 15 175 55.1 175 15 185 56.9 176 15 195 60.5 177 15 205 60.7 178 15 215 66.8 179 15 225 74.5 180 15 235 76.1 181 15 245 62.8 182 15 255 42.4 183 15 265 43.2 184 15 275 49.1 185 15 285 52.2 186 15 295 48.5 187 15 305 51.4 188 15 315 54.1 189 15 325 59.6 190 15 335 55.6 191 15 345 33.2 193 5 5 68.5 197 5 45 42.6 198 5 55 43.7 199 5 65 44.9 200 5 75 53.2 201 5 85 61.4 202 5 95 68.3 203 5 105 57.0 204 5 115 55.5 205 5 125 57.6 206 5 135 63.2 207 5 145 66.4 208 5 155 68.1 209 5 165 67.8 210 5 175 65.2 211 5 185 65.2 212 5 195 66.2 213 5 205 67.6 214 5 215 68.3 215 5 225 67.6 216 5 235 64.8 217 5 245 61.8 218 5 255 56.0 219 5 265 57.5 220 5 275 62.1 221 5 285 63.4 222 5 295 57.3 223 5 305 60.9 224 5 315 69.3 225 5 325 68.3 226 5 335 65.4 227 5 345 58.6 228 5 355 66.8 229 -5 5 64.3 230 -5 15 59.2 232 -5 35 56.0 233 -5 45 50.6 234 -5 55 51.1 235 -5 65 54.8 236 -5 75 59.8 237 -5 85 63.0 238 -5 95 67.3 239 -5 105 67.5 240 -5 115 61.4 241 -5 125 58.4 242 -5 135 66.6 243 -5 145 71.2 244 -5 155 69.6 245 -5 165 66.9 246 -5 175 62.7 247 -5 185 59.7 248 -5 195 55.5 249 -5 205 51.8 250 -5 215 49.6 251 -5 225 48.4 252 -5 235 48.8 253 -5 245 52.8 254 -5 255 54.4 255 -5 265 58.0 256 -5 275 58.3 257 -5 285 57.6 260 -5 315 69.4 261 -5 325 61.3 262 -5 335 55.1 263 -5 345 50.5 264 -5 355 55.7 265 -15 5 71.5 266 -15 15 64.5 268 -15 35 45.5 269 -15 45 50.1 270 -15 55 55.7 271 -15 65 56.1 272 -15 75 57.6 273 -15 85 61.9 274 -15 95 64.3 275 -15 105 56.6 276 -15 115 41.9 277 -15 125 41.9 278 -15 135 60.3 279 -15 145 63.6 280 -15 155 64.3 281 -15 165 65.1 282 -15 175 66.4 283 -15 185 66.5 284 -15 195 62.7 285 -15 205 57.7 286 -15 215 53.2 287 -15 225 49.9 288 -15 235 49.0 289 -15 245 49.6 290 -15 255 54.3 291 -15 265 63.5 292 -15 275 72.1 293 -15 285 63.3 297 -15 325 54.8 298 -15 335 49.4 299 -15 345 49.8 300 -15 355 63.8 301 -25 5 68.4 302 -25 15 52.5 304 -25 35 48.1 305 -25 45 53.2 306 -25 55 58.0 307 -25 65 60.4 308 -25 75 61.0 309 -25 85 63.7 310 -25 95 65.3 311 -25 105 63.3 312 -25 115 43.2 315 -25 145 60.4 316 -25 155 56.6 317 -25 165 60.7 318 -25 175 65.2 319 -25 185 67.5 320 -25 195 69.2 321 -25 205 68.8 322 -25 215 66.8 323 -25 225 63.1 324 -25 235 57.7 325 -25 245 56.2 326 -25 255 55.8 327 -25 265 64.4 328 -25 275 70.3 329 -25 285 76.5 332 -25 315 58.8 333 -25 325 58.1 334 -25 335 59.5 335 -25 345 56.1 336 -25 355 62.6 337 -35 5 71.9 338 -35 15 52.8 339 -35 25 53.6 340 -35 35 56.5 341 -35 45 63.2 342 -35 55 68.5 343 -35 65 70.3 344 -35 75 71.8 345 -35 85 74.1 346 -35 95 76.1 347 -35 105 72.7 348 -35 115 61.8 349 -35 125 70.2 350 -35 135 69.5 351 -35 145 63.7 352 -35 155 60.3 353 -35 165 67.7 354 -35 175 62.3 355 -35 185 68.3 356 -35 195 70.9 357 -35 205 73.0 358 -35 215 75.8 359 -35 225 74.9 360 -35 235 69.3 361 -35 245 70.7 362 -35 255 75.9 363 -35 265 73.6 364 -35 275 74.9 365 -35 285 67.6 366 -35 295 56.3 367 -35 305 55.4 368 -35 315 62.9 369 -35 325 68.8 370 -35 335 70.2 371 -35 345 69.4 372 -35 355 70.4 373 -45 5 81.7 374 -45 15 81.3 375 -45 25 82.9 376 -45 35 83.4 377 -45 45 81.4 378 -45 55 81.4 379 -45 65 81.8 380 -45 75 81.0 381 -45 85 84.9 382 -45 95 83.4 383 -45 105 83.2 384 -45 115 82.4 385 -45 125 82.4 386 -45 135 78.4 387 -45 145 68.1 388 -45 155 73.6 389 -45 165 78.3 390 -45 175 62.7 391 -45 185 76.3 392 -45 195 78.7 393 -45 205 80.0 394 -45 215 81.8 395 -45 225 80.6 396 -45 235 82.5 397 -45 245 82.6 398 -45 255 80.9 399 -45 265 79.3 400 -45 275 81.5 401 -45 285 79.9 402 -45 295 59.6 403 -45 305 64.7 404 -45 315 75.1 405 -45 325 78.0 406 -45 335 78.3 407 -45 345 76.4 408 -45 355 78.0 409 -55 10 86.6 410 -55 30 86.8 411 -55 50 84.8 412 -55 70 85.4 413 -55 90 86.2 414 -55 110 87.0 415 -55 130 84.8 416 -55 150 85.2 417 -55 170 83.3 418 -55 190 86.6 419 -55 210 86.4 420 -55 230 85.1 421 -55 250 88.5 422 -55 270 83.8 423 -55 290 76.1 424 -55 310 80.0 425 -55 330 81.6 426 -55 350 87.9 427 -65 10 84.8 428 -65 30 86.5 429 -65 50 83.8 430 -65 70 86.6 431 -65 90 89.5 432 -65 110 88.7 433 -65 130 88.0 434 -65 150 86.0 435 -65 170 88.8 436 -65 190 90.2 437 -65 210 92.5 438 -65 230 87.9 439 -65 250 90.7 440 -65 270 89.8 441 -65 290 84.7 442 -65 310 89.2 443 -65 330 89.3 444 -65 350 88.1 449 -75 180 87.7 450 -75 220 87.7 451 -75 260 81.3 452 -75 300 77.7 453 -75 340 72.6