Total Cloud Cover Average Cloud Amount (%) May (1954 - 1997) Night, Ship Observations Only Global Average: 67.9 Zonal Averages 16 zones Lat.N Average 85 74.9 75 80.1 65 80.1 55 82.0 45 79.9 35 69.2 25 59.5 15 57.2 5 66.5 -5 56.3 -15 58.2 -25 62.2 -35 67.8 -45 75.9 -55 80.6 -65 90.0 Grid Box Averages 327 filled boxes Box # Lat.N Lon.E Average 1 85 60 78.1 2 85 180 75.3 3 85 300 70.0 4 75 20 83.4 5 75 60 85.2 6 75 100 72.9 7 75 140 72.1 8 75 180 78.3 9 75 220 87.7 11 75 300 65.3 12 75 340 81.9 13 65 10 75.2 14 65 30 79.0 15 65 50 73.1 20 65 150 70.2 21 65 170 79.3 22 65 190 86.0 23 65 210 75.9 27 65 290 75.6 28 65 310 80.3 29 65 330 82.3 30 65 350 81.7 31 55 10 62.6 32 55 30 52.2 37 55 130 74.2 38 55 150 79.5 39 55 170 86.9 40 55 190 87.9 41 55 210 84.9 42 55 230 81.7 46 55 310 85.5 47 55 330 84.8 48 55 350 73.6 49 45 5 49.1 50 45 15 47.8 51 45 25 44.9 52 45 35 44.7 53 45 45 53.2 54 45 55 49.9 62 45 135 62.2 63 45 145 73.7 64 45 155 85.6 65 45 165 91.0 66 45 175 92.2 67 45 185 91.1 68 45 195 88.6 69 45 205 88.4 70 45 215 88.0 71 45 225 84.5 72 45 235 70.6 77 45 285 60.1 78 45 295 66.5 79 45 305 74.3 80 45 315 80.3 81 45 325 80.7 82 45 335 81.3 83 45 345 76.0 84 45 355 67.2 85 35 5 49.1 86 35 15 40.6 87 35 25 35.1 88 35 35 31.1 96 35 115 54.7 97 35 125 64.2 98 35 135 66.7 99 35 145 73.0 100 35 155 81.5 101 35 165 84.2 102 35 175 81.5 103 35 185 81.7 104 35 195 79.4 105 35 205 80.2 106 35 215 78.5 107 35 225 77.9 108 35 235 65.6 109 35 245 66.0 112 35 275 47.2 113 35 285 56.8 114 35 295 64.5 115 35 305 67.0 116 35 315 65.1 117 35 325 64.4 118 35 335 69.3 119 35 345 66.9 120 35 355 47.8 124 25 35 17.3 125 25 45 27.7 126 25 55 14.7 127 25 65 24.8 129 25 85 62.2 132 25 115 67.7 133 25 125 70.0 134 25 135 68.0 135 25 145 62.2 136 25 155 61.6 137 25 165 58.4 138 25 175 60.4 139 25 185 59.5 140 25 195 59.2 141 25 205 59.9 142 25 215 67.5 143 25 225 78.5 144 25 235 80.9 145 25 245 61.5 146 25 255 41.7 147 25 265 53.1 148 25 275 47.0 149 25 285 55.1 150 25 295 56.6 151 25 305 56.2 152 25 315 53.2 153 25 325 55.5 154 25 335 62.0 155 25 345 48.7 160 15 35 18.7 161 15 45 27.3 162 15 55 32.1 163 15 65 37.8 164 15 75 52.0 165 15 85 59.2 166 15 95 67.1 167 15 105 58.4 168 15 115 49.8 169 15 125 50.0 170 15 135 48.2 171 15 145 48.6 172 15 155 50.2 173 15 165 56.5 174 15 175 58.5 175 15 185 60.2 176 15 195 63.3 177 15 205 62.5 178 15 215 68.9 179 15 225 79.6 180 15 235 81.9 181 15 245 66.1 182 15 255 51.1 183 15 265 58.9 184 15 275 59.8 185 15 285 59.4 186 15 295 53.7 187 15 305 55.0 188 15 315 57.8 189 15 325 62.5 190 15 335 60.0 191 15 345 38.2 193 5 5 70.3 197 5 45 46.1 198 5 55 48.2 199 5 65 54.2 200 5 75 63.3 201 5 85 68.3 202 5 95 75.9 203 5 105 58.1 204 5 115 57.6 205 5 125 59.7 206 5 135 64.5 207 5 145 70.5 208 5 155 70.2 209 5 165 68.5 210 5 175 67.3 211 5 185 65.9 212 5 195 68.0 213 5 205 69.6 214 5 215 66.6 215 5 225 70.9 216 5 235 64.1 217 5 245 73.1 218 5 255 65.5 219 5 265 69.6 220 5 275 76.1 221 5 285 72.3 223 5 305 65.8 224 5 315 71.0 225 5 325 68.8 226 5 335 69.5 227 5 345 65.8 228 5 355 70.7 229 -5 5 65.8 230 -5 15 47.3 233 -5 45 54.2 234 -5 55 55.4 235 -5 65 55.9 236 -5 75 62.5 237 -5 85 64.2 238 -5 95 67.6 239 -5 105 64.5 240 -5 115 52.6 241 -5 125 53.0 242 -5 135 61.3 243 -5 145 70.6 244 -5 155 69.2 245 -5 165 62.4 246 -5 175 54.6 247 -5 185 54.4 248 -5 195 49.6 249 -5 205 48.5 250 -5 215 46.1 251 -5 225 47.7 252 -5 235 45.4 253 -5 245 45.0 254 -5 255 50.8 255 -5 265 58.9 256 -5 275 66.2 257 -5 285 63.0 260 -5 315 62.4 261 -5 325 60.9 262 -5 335 51.3 263 -5 345 48.7 264 -5 355 58.7 265 -15 5 73.0 266 -15 15 51.2 268 -15 35 35.2 269 -15 45 38.8 270 -15 55 57.0 271 -15 65 58.6 272 -15 75 60.0 273 -15 85 63.3 274 -15 95 65.5 275 -15 105 56.6 276 -15 115 37.9 277 -15 125 27.8 278 -15 135 54.0 279 -15 145 59.4 280 -15 155 63.4 281 -15 165 66.8 282 -15 175 63.1 283 -15 185 65.8 284 -15 195 62.0 285 -15 205 56.3 286 -15 215 50.6 287 -15 225 49.9 288 -15 235 49.1 289 -15 245 46.6 290 -15 255 55.8 291 -15 265 70.3 292 -15 275 83.2 293 -15 285 70.8 297 -15 325 53.8 298 -15 335 49.3 299 -15 345 54.7 300 -15 355 71.1 301 -25 5 68.8 302 -25 15 44.1 304 -25 35 40.7 305 -25 45 50.6 306 -25 55 56.9 307 -25 65 62.9 308 -25 75 62.8 309 -25 85 66.4 310 -25 95 66.3 311 -25 105 60.9 312 -25 115 41.7 316 -25 155 55.9 317 -25 165 61.8 318 -25 175 65.5 319 -25 185 68.3 320 -25 195 70.7 321 -25 205 69.6 322 -25 215 69.5 323 -25 225 66.2 324 -25 235 57.8 325 -25 245 56.6 326 -25 255 57.4 327 -25 265 63.9 328 -25 275 71.0 329 -25 285 73.8 332 -25 315 57.2 333 -25 325 59.6 334 -25 335 61.2 335 -25 345 58.3 336 -25 355 64.3 337 -35 5 74.2 338 -35 15 53.1 339 -35 25 49.4 340 -35 35 49.1 341 -35 45 64.4 342 -35 55 69.2 343 -35 65 68.8 344 -35 75 72.7 345 -35 85 74.6 346 -35 95 77.3 347 -35 105 71.2 348 -35 115 63.1 349 -35 125 68.4 350 -35 135 69.7 351 -35 145 67.8 352 -35 155 62.1 353 -35 165 69.9 354 -35 175 62.5 355 -35 185 67.7 356 -35 195 68.3 357 -35 205 70.0 358 -35 215 78.2 359 -35 225 75.2 360 -35 235 74.6 364 -35 275 73.4 365 -35 285 65.7 367 -35 305 57.5 368 -35 315 61.2 369 -35 325 70.8 370 -35 335 64.9 371 -35 345 69.1 372 -35 355 69.6 386 -45 135 82.2 387 -45 145 67.1 388 -45 155 76.0 389 -45 165 80.3 390 -45 175 61.5 391 -45 185 76.5 392 -45 195 78.4 393 -45 205 80.7 397 -45 245 80.7 398 -45 255 79.9 399 -45 265 73.1 400 -45 275 78.7 401 -45 285 82.5 402 -45 295 66.5 403 -45 305 66.3 404 -45 315 78.0 405 -45 325 78.1 417 -55 170 85.6 422 -55 270 80.0 423 -55 290 74.5 424 -55 310 85.1 425 -55 330 76.7 442 -65 310 90.0