Altocumulus Average Cloud Amount (%) April (1954 - 1997) Day, Ship Observations Only Global Average: 17.0 Zonal Averages 16 zones Lat.N Average 85 10.3 75 10.9 65 14.7 55 14.3 45 15.2 35 16.7 25 13.7 15 11.7 5 18.5 -5 17.2 -15 15.5 -25 17.6 -35 18.8 -45 20.0 -55 20.5 -65 25.2 Grid Box Averages 366 filled boxes Box # Lat.N Lon.E Average 1 85 60 13.4 2 85 180 7.5 3 85 300 10.1 4 75 20 15.5 5 75 60 10.9 7 75 140 12.2 8 75 180 6.6 9 75 220 8.9 11 75 300 12.9 12 75 340 11.5 13 65 10 19.7 14 65 30 12.7 15 65 50 11.4 21 65 170 6.8 22 65 190 6.1 23 65 210 10.9 29 65 330 17.1 30 65 350 17.6 31 55 10 15.8 32 55 30 18.1 38 55 150 9.2 39 55 170 10.9 40 55 190 12.6 41 55 210 14.9 42 55 230 15.0 46 55 310 14.0 47 55 330 18.8 48 55 350 18.4 49 45 5 15.1 50 45 15 15.5 51 45 25 12.6 52 45 35 9.4 53 45 45 11.8 54 45 55 10.6 62 45 135 9.6 63 45 145 9.8 64 45 155 11.4 65 45 165 12.2 66 45 175 13.8 67 45 185 15.2 68 45 195 16.3 69 45 205 16.1 70 45 215 17.0 71 45 225 16.2 72 45 235 15.8 77 45 285 11.6 78 45 295 13.2 79 45 305 16.0 80 45 315 17.6 81 45 325 19.4 82 45 335 19.5 83 45 345 16.7 84 45 355 15.3 85 35 5 15.2 86 35 15 13.1 87 35 25 11.2 88 35 35 9.4 89 35 45 12.8 90 35 55 4.4 96 35 115 4.9 97 35 125 14.7 98 35 135 14.7 99 35 145 13.9 100 35 155 15.8 101 35 165 17.0 102 35 175 18.7 103 35 185 19.4 104 35 195 20.0 105 35 205 21.2 106 35 215 20.9 107 35 225 17.7 108 35 235 11.8 109 35 245 7.7 112 35 275 12.2 113 35 285 15.0 114 35 295 16.3 115 35 305 17.3 116 35 315 18.7 117 35 325 19.0 118 35 335 19.1 119 35 345 14.0 120 35 355 13.6 124 25 35 4.4 125 25 45 9.3 126 25 55 8.5 127 25 65 4.5 128 25 75 5.8 129 25 85 8.1 130 25 95 7.3 131 25 105 18.3 132 25 115 20.2 133 25 125 17.7 134 25 135 14.4 135 25 145 13.4 136 25 155 14.1 137 25 165 13.8 138 25 175 12.4 139 25 185 12.8 140 25 195 14.2 141 25 205 14.0 142 25 215 18.1 143 25 225 20.2 144 25 235 16.9 145 25 245 12.1 146 25 255 10.3 147 25 265 14.4 148 25 275 11.5 149 25 285 11.5 150 25 295 12.2 151 25 305 13.4 152 25 315 14.2 153 25 325 14.4 154 25 335 11.5 155 25 345 7.2 160 15 35 3.9 161 15 45 6.5 162 15 55 4.1 163 15 65 3.2 164 15 75 6.1 165 15 85 7.6 166 15 95 6.2 167 15 105 13.8 168 15 115 7.4 169 15 125 8.3 170 15 135 7.8 171 15 145 8.6 172 15 155 9.8 173 15 165 10.8 174 15 175 11.6 175 15 185 13.7 176 15 195 16.1 177 15 205 16.8 178 15 215 20.1 179 15 225 24.5 180 15 235 25.4 181 15 245 16.3 182 15 255 8.7 183 15 265 7.4 184 15 275 9.7 185 15 285 11.0 186 15 295 11.1 187 15 305 12.2 188 15 315 13.0 189 15 325 12.9 190 15 335 9.1 191 15 345 6.0 193 5 5 21.8 197 5 45 7.1 198 5 55 6.4 199 5 65 7.9 200 5 75 14.0 201 5 85 22.0 202 5 95 26.4 203 5 105 15.0 204 5 115 14.3 205 5 125 15.5 206 5 135 15.7 207 5 145 18.4 208 5 155 22.4 209 5 165 23.6 210 5 175 18.4 211 5 185 24.1 212 5 195 22.5 213 5 205 21.8 214 5 215 20.8 215 5 225 18.9 216 5 235 16.8 217 5 245 17.0 218 5 255 16.5 219 5 265 16.0 220 5 275 22.5 221 5 285 23.3 223 5 305 16.9 224 5 315 22.2 225 5 325 21.6 226 5 335 17.0 227 5 345 18.0 228 5 355 22.8 229 -5 5 19.4 230 -5 15 23.6 232 -5 35 13.7 233 -5 45 12.1 234 -5 55 9.5 235 -5 65 15.0 236 -5 75 18.5 237 -5 85 23.3 238 -5 95 25.3 239 -5 105 26.5 240 -5 115 25.2 241 -5 125 18.9 242 -5 135 23.1 243 -5 145 28.2 244 -5 155 26.2 245 -5 165 23.2 246 -5 175 20.0 247 -5 185 16.3 248 -5 195 16.1 249 -5 205 9.4 250 -5 215 11.6 251 -5 225 10.1 252 -5 235 11.8 253 -5 245 13.3 254 -5 255 14.0 255 -5 265 16.2 256 -5 275 16.6 257 -5 285 20.1 260 -5 315 32.6 261 -5 325 20.8 262 -5 335 15.0 263 -5 345 11.0 264 -5 355 14.2 265 -15 5 11.8 266 -15 15 28.0 268 -15 35 9.7 269 -15 45 14.5 270 -15 55 13.7 271 -15 65 13.5 272 -15 75 18.1 273 -15 85 19.7 274 -15 95 19.2 275 -15 105 15.0 276 -15 115 10.5 277 -15 125 10.1 278 -15 135 21.5 279 -15 145 18.8 280 -15 155 18.5 281 -15 165 18.6 282 -15 175 23.1 283 -15 185 22.6 284 -15 195 20.2 285 -15 205 17.5 286 -15 215 12.1 287 -15 225 10.5 288 -15 235 11.1 289 -15 245 12.4 290 -15 255 15.3 291 -15 265 16.2 292 -15 275 16.6 293 -15 285 16.1 297 -15 325 16.7 298 -15 335 10.1 299 -15 345 10.0 300 -15 355 12.3 301 -25 5 11.1 302 -25 15 12.7 304 -25 35 11.6 305 -25 45 14.1 306 -25 55 17.5 307 -25 65 16.7 308 -25 75 17.2 309 -25 85 15.2 310 -25 95 18.8 311 -25 105 18.7 312 -25 115 14.2 315 -25 145 14.2 316 -25 155 14.3 317 -25 165 16.1 318 -25 175 18.8 319 -25 185 20.5 320 -25 195 24.7 321 -25 205 25.6 322 -25 215 21.1 323 -25 225 18.6 324 -25 235 16.1 325 -25 245 16.1 326 -25 255 17.8 327 -25 265 19.1 328 -25 275 15.9 329 -25 285 18.9 332 -25 315 21.8 333 -25 325 19.1 334 -25 335 17.9 335 -25 345 16.4 336 -25 355 14.6 337 -35 5 19.9 338 -35 15 14.1 339 -35 25 15.5 340 -35 35 15.0 341 -35 45 16.3 342 -35 55 17.7 343 -35 65 20.3 344 -35 75 17.8 345 -35 85 19.5 346 -35 95 19.9 347 -35 105 21.1 348 -35 115 19.0 349 -35 125 20.5 350 -35 135 20.9 351 -35 145 19.1 352 -35 155 15.8 353 -35 165 17.8 354 -35 175 17.7 355 -35 185 15.9 356 -35 195 20.5 357 -35 205 20.4 358 -35 215 22.4 359 -35 225 22.8 360 -35 235 21.1 361 -35 245 22.3 362 -35 255 22.4 363 -35 265 16.7 364 -35 275 13.3 365 -35 285 15.4 367 -35 305 13.9 368 -35 315 18.3 369 -35 325 19.7 370 -35 335 20.0 371 -35 345 19.8 372 -35 355 20.9 373 -45 5 17.8 374 -45 15 28.9 375 -45 25 23.1 376 -45 35 24.2 377 -45 45 25.4 378 -45 55 19.3 379 -45 65 19.3 380 -45 75 18.6 381 -45 85 28.9 382 -45 95 20.4 383 -45 105 20.9 384 -45 115 25.0 385 -45 125 21.1 386 -45 135 24.6 387 -45 145 19.0 388 -45 155 19.3 389 -45 165 16.5 390 -45 175 17.4 391 -45 185 21.4 392 -45 195 20.6 393 -45 205 15.5 394 -45 215 20.2 395 -45 225 25.4 396 -45 235 21.9 397 -45 245 13.2 398 -45 255 6.9 399 -45 265 14.8 400 -45 275 12.4 401 -45 285 14.4 402 -45 295 13.6 403 -45 305 19.1 404 -45 315 19.9 405 -45 325 22.8 406 -45 335 19.6 407 -45 345 25.3 408 -45 355 18.4 409 -55 10 24.4 410 -55 30 16.2 411 -55 50 21.3 412 -55 70 20.2 416 -55 150 16.6 417 -55 170 23.7 422 -55 270 18.0 423 -55 290 20.0 424 -55 310 28.5 425 -55 330 24.7 426 -55 350 12.5 427 -65 10 26.0 429 -65 50 27.6 430 -65 70 19.7 431 -65 90 23.8 432 -65 110 29.7 433 -65 130 25.1 434 -65 150 30.4 441 -65 290 12.3 442 -65 310 37.0 444 -65 350 20.9