Altocumulus Average Cloud Amount (%) December (1953 - 1996) Night, Ship Observations Only Global Average: 17.5 Zonal Averages 17 zones Lat.N Average 85 7.5 75 11.2 65 11.5 55 11.0 45 12.2 35 15.2 25 13.8 15 12.5 5 19.6 -5 19.1 -15 18.9 -25 18.8 -35 17.5 -45 21.0 -55 23.6 -65 21.7 -75 17.7 Grid Box Averages 348 filled boxes Box # Lat.N Lon.E Average 2 85 180 7.5 4 75 20 11.7 5 75 60 6.1 8 75 180 11.7 9 75 220 14.7 13 65 10 15.2 14 65 30 12.5 15 65 50 10.2 21 65 170 3.7 22 65 190 5.5 29 65 330 11.6 30 65 350 14.6 31 55 10 12.6 32 55 30 15.2 38 55 150 7.7 39 55 170 10.3 40 55 190 9.4 41 55 210 10.7 42 55 230 10.0 46 55 310 10.8 47 55 330 14.3 48 55 350 12.8 49 45 5 13.9 50 45 15 15.3 51 45 25 8.1 52 45 35 10.6 62 45 135 6.2 63 45 145 7.5 64 45 155 10.2 65 45 165 11.4 66 45 175 11.0 67 45 185 11.0 68 45 195 11.6 69 45 205 10.9 70 45 215 11.7 71 45 225 11.8 72 45 235 12.7 77 45 285 9.7 78 45 295 11.9 79 45 305 14.3 80 45 315 14.8 81 45 325 15.1 82 45 335 15.1 83 45 345 14.5 84 45 355 14.3 85 35 5 14.4 86 35 15 14.2 87 35 25 14.8 88 35 35 13.0 97 35 125 13.1 98 35 135 13.0 99 35 145 10.6 100 35 155 13.8 101 35 165 15.3 102 35 175 13.4 103 35 185 14.3 104 35 195 16.6 105 35 205 16.6 106 35 215 16.7 107 35 225 14.7 108 35 235 11.9 109 35 245 9.1 112 35 275 15.9 113 35 285 17.1 114 35 295 18.0 115 35 305 17.6 116 35 315 18.1 117 35 325 17.1 118 35 335 18.0 119 35 345 15.4 120 35 355 14.3 124 25 35 5.3 126 25 55 6.5 127 25 65 4.4 129 25 85 8.3 132 25 115 15.2 133 25 125 17.6 134 25 135 15.7 135 25 145 15.6 136 25 155 14.3 137 25 165 11.6 138 25 175 12.7 139 25 185 12.9 140 25 195 10.4 141 25 205 11.5 142 25 215 17.3 143 25 225 18.0 144 25 235 15.5 145 25 245 13.9 146 25 255 16.5 147 25 265 20.6 148 25 275 16.8 149 25 285 14.5 150 25 295 13.1 151 25 305 11.7 152 25 315 12.4 153 25 325 13.3 154 25 335 12.9 155 25 345 10.3 160 15 35 5.6 161 15 45 4.3 162 15 55 5.7 163 15 65 6.3 164 15 75 6.7 165 15 85 11.2 166 15 95 8.6 167 15 105 15.5 168 15 115 14.2 169 15 125 12.8 170 15 135 13.4 171 15 145 12.6 172 15 155 8.7 173 15 165 8.0 174 15 175 8.7 175 15 185 11.7 176 15 195 12.1 177 15 205 14.4 178 15 215 18.4 179 15 225 17.6 180 15 235 22.9 181 15 245 18.0 182 15 255 12.8 183 15 265 8.4 184 15 275 13.9 185 15 285 10.4 186 15 295 9.7 187 15 305 10.8 188 15 315 13.6 189 15 325 15.1 190 15 335 17.4 191 15 345 12.0 193 5 5 20.3 197 5 45 10.5 198 5 55 13.4 199 5 65 11.0 200 5 75 16.3 201 5 85 22.4 202 5 95 28.4 203 5 105 24.3 204 5 115 24.0 205 5 125 19.5 206 5 135 23.2 207 5 145 18.3 208 5 155 18.3 209 5 165 20.8 210 5 175 22.7 211 5 185 19.2 212 5 195 18.2 213 5 205 17.8 214 5 215 13.7 215 5 225 18.8 216 5 235 28.3 217 5 245 18.8 218 5 255 18.1 219 5 265 16.0 220 5 275 24.1 221 5 285 22.4 223 5 305 18.3 224 5 315 20.2 225 5 325 23.0 226 5 335 21.3 227 5 345 14.8 228 5 355 18.5 229 -5 5 33.1 230 -5 15 21.0 232 -5 35 11.5 233 -5 45 12.2 234 -5 55 16.4 235 -5 65 20.8 236 -5 75 20.3 237 -5 85 24.8 238 -5 95 24.9 239 -5 105 33.4 240 -5 115 32.7 241 -5 125 24.9 242 -5 135 24.1 243 -5 145 25.3 244 -5 155 21.5 245 -5 165 22.2 246 -5 175 24.4 247 -5 185 20.4 248 -5 195 17.8 249 -5 205 10.4 250 -5 215 7.0 251 -5 225 5.1 252 -5 235 6.1 253 -5 245 10.6 254 -5 255 18.3 255 -5 265 21.1 256 -5 275 31.3 257 -5 285 20.4 260 -5 315 12.1 261 -5 325 10.1 262 -5 335 11.0 263 -5 345 17.3 264 -5 355 21.6 265 -15 5 24.7 266 -15 15 18.1 268 -15 35 18.4 269 -15 45 16.3 270 -15 55 15.4 271 -15 65 15.4 272 -15 75 18.1 273 -15 85 19.4 274 -15 95 22.2 275 -15 105 16.4 276 -15 115 14.0 277 -15 125 14.2 278 -15 135 18.4 279 -15 145 17.0 280 -15 155 14.1 281 -15 165 14.3 282 -15 175 22.6 283 -15 185 23.7 284 -15 195 26.0 285 -15 205 21.2 286 -15 215 14.4 287 -15 225 13.8 288 -15 235 16.5 289 -15 245 19.2 290 -15 255 21.3 291 -15 265 24.9 292 -15 275 27.8 293 -15 285 19.4 297 -15 325 17.8 298 -15 335 10.7 299 -15 345 21.1 300 -15 355 22.7 301 -25 5 16.1 302 -25 15 10.9 304 -25 35 17.1 305 -25 45 15.4 306 -25 55 18.3 307 -25 65 14.2 308 -25 75 16.6 309 -25 85 22.0 310 -25 95 25.3 311 -25 105 16.6 312 -25 115 9.4 316 -25 155 14.1 317 -25 165 16.4 318 -25 175 20.4 319 -25 185 18.8 320 -25 195 20.6 321 -25 205 19.6 322 -25 215 18.6 323 -25 225 19.3 324 -25 235 20.3 325 -25 245 17.6 326 -25 255 20.1 327 -25 265 27.4 328 -25 275 18.5 329 -25 285 17.9 332 -25 315 27.2 333 -25 325 21.1 334 -25 335 15.8 335 -25 345 21.1 336 -25 355 18.7 337 -35 5 18.4 338 -35 15 9.6 339 -35 25 14.1 340 -35 35 16.0 341 -35 45 18.6 342 -35 55 14.5 343 -35 65 19.1 344 -35 75 20.0 345 -35 85 21.3 346 -35 95 22.5 347 -35 105 18.4 348 -35 115 14.2 349 -35 125 17.8 350 -35 135 18.4 351 -35 145 15.3 352 -35 155 16.5 353 -35 165 19.9 354 -35 175 18.6 355 -35 185 20.2 356 -35 195 18.2 357 -35 205 18.5 358 -35 215 17.7 359 -35 225 16.8 363 -35 265 11.8 364 -35 275 13.7 365 -35 285 8.5 367 -35 305 16.1 368 -35 315 16.5 369 -35 325 17.5 370 -35 335 20.2 371 -35 345 24.2 372 -35 355 19.4 373 -45 5 25.2 374 -45 15 20.6 375 -45 25 22.0 376 -45 35 22.7 379 -45 65 24.7 380 -45 75 22.5 381 -45 85 20.4 382 -45 95 19.9 383 -45 105 23.8 384 -45 115 25.6 385 -45 125 16.2 386 -45 135 18.8 387 -45 145 18.8 388 -45 155 19.7 389 -45 165 25.7 390 -45 175 20.8 391 -45 185 17.5 392 -45 195 19.5 393 -45 205 22.1 400 -45 275 19.5 401 -45 285 17.4 402 -45 295 14.5 403 -45 305 19.6 404 -45 315 20.7 405 -45 325 21.7 409 -55 10 20.6 410 -55 30 24.4 411 -55 50 25.1 412 -55 70 29.4 413 -55 90 27.0 414 -55 110 21.7 415 -55 130 15.9 416 -55 150 17.1 417 -55 170 23.8 420 -55 230 23.4 422 -55 270 23.7 423 -55 290 20.2 424 -55 310 27.0 425 -55 330 28.4 426 -55 350 25.6 427 -65 10 18.5 428 -65 30 20.8 429 -65 50 26.1 430 -65 70 16.9 431 -65 90 23.6 432 -65 110 15.1 433 -65 130 15.3 434 -65 150 22.8 435 -65 170 20.1 436 -65 190 23.6 437 -65 210 22.5 438 -65 230 25.3 441 -65 290 19.4 442 -65 310 39.2 443 -65 330 19.1 444 -65 350 15.5 449 -75 180 17.4 453 -75 340 18.1