Altocumulus Average Cloud Amount (%) May (1954 - 1997) Day, Ship Observations Only Global Average: 18.0 Zonal Averages 16 zones Lat.N Average 85 10.9 75 13.0 65 17.6 55 16.9 45 17.2 35 17.1 25 14.3 15 14.1 5 21.8 -5 15.2 -15 14.7 -25 17.2 -35 18.2 -45 16.8 -55 19.5 -65 42.7 Grid Box Averages 350 filled boxes Box # Lat.N Lon.E Average 1 85 60 15.8 2 85 180 6.9 3 85 300 10.0 4 75 20 19.7 5 75 60 17.3 7 75 140 5.5 8 75 180 8.8 9 75 220 9.3 11 75 300 18.2 12 75 340 16.4 13 65 10 20.4 14 65 30 15.4 15 65 50 16.8 20 65 150 11.5 21 65 170 10.9 22 65 190 13.2 23 65 210 19.6 29 65 330 19.7 30 65 350 19.0 31 55 10 15.6 32 55 30 16.6 37 55 130 13.1 38 55 150 12.4 39 55 170 15.1 40 55 190 17.0 41 55 210 17.6 42 55 230 17.6 45 55 290 11.3 46 55 310 17.8 47 55 330 19.7 48 55 350 19.1 49 45 5 14.6 50 45 15 13.9 51 45 25 11.3 52 45 35 8.4 53 45 45 11.7 54 45 55 7.6 62 45 135 12.3 63 45 145 12.6 64 45 155 14.1 65 45 165 15.3 66 45 175 17.6 67 45 185 18.8 68 45 195 18.9 69 45 205 20.6 70 45 215 19.1 71 45 225 19.0 72 45 235 15.1 77 45 285 14.7 78 45 295 15.0 79 45 305 16.6 80 45 315 18.9 81 45 325 19.9 82 45 335 19.9 83 45 345 17.7 84 45 355 16.9 85 35 5 13.2 86 35 15 11.2 87 35 25 9.1 88 35 35 7.7 90 35 55 6.7 96 35 115 15.6 97 35 125 16.1 98 35 135 17.6 99 35 145 15.8 100 35 155 17.4 101 35 165 18.3 102 35 175 18.3 103 35 185 21.1 104 35 195 21.4 105 35 205 21.9 106 35 215 21.4 107 35 225 18.3 108 35 235 12.8 109 35 245 8.8 112 35 275 12.3 113 35 285 16.2 114 35 295 16.6 115 35 305 17.3 116 35 315 17.7 117 35 325 18.0 118 35 335 18.3 119 35 345 13.5 120 35 355 11.4 124 25 35 4.7 125 25 45 4.3 126 25 55 3.2 127 25 65 2.7 128 25 75 3.2 129 25 85 10.8 130 25 95 15.9 131 25 105 18.6 132 25 115 21.5 133 25 125 21.0 134 25 135 18.6 135 25 145 15.7 136 25 155 13.2 137 25 165 12.3 138 25 175 12.3 139 25 185 13.8 140 25 195 13.2 141 25 205 13.2 142 25 215 16.9 143 25 225 21.7 144 25 235 19.2 145 25 245 12.2 146 25 255 8.5 147 25 265 12.2 148 25 275 12.4 149 25 285 14.2 150 25 295 15.9 151 25 305 15.2 152 25 315 13.2 153 25 325 12.7 154 25 335 12.1 155 25 345 8.1 160 15 35 5.5 161 15 45 4.8 162 15 55 4.3 163 15 65 6.1 164 15 75 10.7 165 15 85 13.0 166 15 95 19.4 167 15 105 18.7 168 15 115 12.6 169 15 125 11.3 170 15 135 9.8 171 15 145 9.1 172 15 155 10.8 173 15 165 15.6 174 15 175 14.4 175 15 185 14.1 176 15 195 16.0 177 15 205 17.2 178 15 215 19.7 179 15 225 24.5 180 15 235 24.9 181 15 245 14.0 182 15 255 9.8 183 15 265 15.9 184 15 275 17.8 185 15 285 16.0 186 15 295 15.5 187 15 305 13.7 188 15 315 14.6 189 15 325 13.9 190 15 335 11.7 191 15 345 9.2 193 5 5 27.0 197 5 45 11.5 198 5 55 13.3 199 5 65 15.8 200 5 75 21.6 201 5 85 25.1 202 5 95 33.4 203 5 105 21.9 204 5 115 21.5 205 5 125 18.8 206 5 135 19.5 207 5 145 20.9 208 5 155 20.2 209 5 165 27.9 210 5 175 26.6 211 5 185 18.5 212 5 195 18.9 213 5 205 19.2 214 5 215 20.1 215 5 225 19.5 216 5 235 16.9 217 5 245 21.6 218 5 255 19.8 219 5 265 22.9 220 5 275 33.1 221 5 285 31.4 223 5 305 19.3 224 5 315 22.5 225 5 325 21.3 226 5 335 21.0 227 5 345 24.9 228 5 355 27.5 229 -5 5 14.9 230 -5 15 16.0 232 -5 35 21.9 233 -5 45 13.2 234 -5 55 13.5 235 -5 65 18.6 236 -5 75 19.8 237 -5 85 26.0 238 -5 95 25.3 239 -5 105 22.7 240 -5 115 19.9 241 -5 125 18.5 242 -5 135 23.6 243 -5 145 25.5 244 -5 155 24.2 245 -5 165 19.9 246 -5 175 15.6 247 -5 185 15.8 248 -5 195 12.2 249 -5 205 9.5 250 -5 215 6.1 251 -5 225 6.7 252 -5 235 7.2 253 -5 245 7.5 254 -5 255 9.6 255 -5 265 11.9 256 -5 275 15.0 257 -5 285 25.6 260 -5 315 23.2 261 -5 325 18.1 262 -5 335 11.7 263 -5 345 9.9 264 -5 355 12.5 265 -15 5 10.5 266 -15 15 27.6 268 -15 35 7.9 269 -15 45 9.9 270 -15 55 13.3 271 -15 65 13.3 272 -15 75 13.5 273 -15 85 17.0 274 -15 95 18.1 275 -15 105 16.4 276 -15 115 12.4 277 -15 125 7.9 278 -15 135 15.2 279 -15 145 17.0 280 -15 155 17.6 281 -15 165 21.0 282 -15 175 20.4 283 -15 185 20.1 284 -15 195 20.5 285 -15 205 18.4 286 -15 215 10.8 287 -15 225 10.8 288 -15 235 10.3 289 -15 245 11.4 290 -15 255 12.2 291 -15 265 13.1 292 -15 275 16.9 293 -15 285 21.3 297 -15 325 15.5 298 -15 335 10.0 299 -15 345 11.5 300 -15 355 12.2 301 -25 5 9.5 302 -25 15 9.9 304 -25 35 9.5 305 -25 45 11.8 306 -25 55 14.6 307 -25 65 14.4 308 -25 75 14.5 309 -25 85 15.9 310 -25 95 16.7 311 -25 105 17.3 312 -25 115 13.2 315 -25 145 16.5 316 -25 155 15.9 317 -25 165 17.9 318 -25 175 21.5 319 -25 185 20.1 320 -25 195 23.1 321 -25 205 23.2 322 -25 215 22.1 323 -25 225 20.9 324 -25 235 18.6 325 -25 245 18.2 326 -25 255 22.4 327 -25 265 15.4 328 -25 275 12.3 329 -25 285 19.4 332 -25 315 20.4 333 -25 325 17.7 334 -25 335 17.5 335 -25 345 15.6 336 -25 355 18.0 337 -35 5 19.3 338 -35 15 13.2 339 -35 25 14.6 340 -35 35 13.1 341 -35 45 14.7 342 -35 55 17.1 343 -35 65 16.6 344 -35 75 15.5 345 -35 85 17.6 346 -35 95 17.4 347 -35 105 15.8 348 -35 115 19.1 349 -35 125 20.4 350 -35 135 20.9 351 -35 145 20.6 352 -35 155 17.8 353 -35 165 17.4 354 -35 175 17.3 355 -35 185 18.3 356 -35 195 15.9 357 -35 205 20.7 358 -35 215 23.5 359 -35 225 23.6 360 -35 235 24.9 361 -35 245 20.8 362 -35 255 16.3 363 -35 265 21.4 364 -35 275 12.7 365 -35 285 15.7 367 -35 305 15.5 368 -35 315 18.6 369 -35 325 19.3 370 -35 335 18.5 371 -35 345 20.4 372 -35 355 21.1 375 -45 25 36.9 376 -45 35 14.7 377 -45 45 18.5 379 -45 65 26.5 380 -45 75 11.9 384 -45 115 10.0 385 -45 125 15.5 386 -45 135 22.0 387 -45 145 18.6 388 -45 155 19.7 389 -45 165 20.5 390 -45 175 16.5 391 -45 185 14.7 392 -45 195 13.1 393 -45 205 12.1 394 -45 215 11.9 395 -45 225 16.9 396 -45 235 11.3 397 -45 245 10.0 398 -45 255 9.7 399 -45 265 9.2 400 -45 275 10.0 401 -45 285 12.1 402 -45 295 17.9 403 -45 305 15.6 404 -45 315 23.0 405 -45 325 25.0 406 -45 335 15.7 407 -45 345 27.7 411 -55 50 21.0 412 -55 70 29.2 417 -55 170 28.9 419 -55 210 6.7 421 -55 250 9.4 422 -55 270 11.1 423 -55 290 18.1 424 -55 310 29.2 425 -55 330 22.2 442 -65 310 42.7