Altocumulus Average Cloud Amount (%) April (1954 - 1997) , Ship Observations Only Global Average: 16.5 Zonal Averages 16 zones Lat.N Average 85 10.3 75 10.7 65 14.7 55 13.4 45 14.6 35 16.2 25 13.7 15 11.9 5 18.0 -5 16.9 -15 15.2 -25 17.0 -35 18.0 -45 19.5 -55 21.4 -65 19.5 Grid Box Averages 372 filled boxes Box # Lat.N Lon.E Average 1 85 60 11.7 2 85 180 9.2 3 85 300 10.0 4 75 20 15.6 5 75 60 11.7 6 75 100 5.4 7 75 140 12.5 8 75 180 7.4 9 75 220 9.2 11 75 300 10.0 12 75 340 11.0 13 65 10 19.5 14 65 30 13.9 15 65 50 10.8 21 65 170 6.8 22 65 190 6.7 23 65 210 10.9 29 65 330 16.6 30 65 350 17.8 31 55 10 15.9 32 55 30 17.9 38 55 150 7.6 39 55 170 10.2 40 55 190 12.1 41 55 210 13.8 42 55 230 13.4 46 55 310 13.0 47 55 330 17.2 48 55 350 17.9 49 45 5 15.3 50 45 15 15.6 51 45 25 13.6 52 45 35 10.8 53 45 45 10.8 54 45 55 9.2 62 45 135 9.1 63 45 145 9.2 64 45 155 10.3 65 45 165 11.9 66 45 175 13.4 67 45 185 15.9 68 45 195 16.3 69 45 205 15.6 70 45 215 15.9 71 45 225 14.9 72 45 235 14.6 77 45 285 11.8 78 45 295 13.1 79 45 305 14.6 80 45 315 16.5 81 45 325 18.5 82 45 335 18.3 83 45 345 16.0 84 45 355 15.2 85 35 5 15.4 86 35 15 13.2 87 35 25 10.9 88 35 35 9.1 89 35 45 11.9 90 35 55 7.9 96 35 115 4.3 97 35 125 13.4 98 35 135 14.0 99 35 145 13.0 100 35 155 15.0 101 35 165 16.6 102 35 175 19.1 103 35 185 21.1 104 35 195 20.0 105 35 205 21.2 106 35 215 19.7 107 35 225 16.1 108 35 235 10.9 109 35 245 7.6 112 35 275 11.9 113 35 285 14.8 114 35 295 15.7 115 35 305 16.2 116 35 315 18.3 117 35 325 17.9 118 35 335 17.5 119 35 345 13.8 120 35 355 13.7 124 25 35 4.6 125 25 45 11.3 126 25 55 8.3 127 25 65 4.4 128 25 75 5.6 129 25 85 10.2 130 25 95 10.4 131 25 105 16.1 132 25 115 19.5 133 25 125 17.1 134 25 135 14.5 135 25 145 14.0 136 25 155 14.0 137 25 165 14.4 138 25 175 13.1 139 25 185 13.7 140 25 195 14.5 141 25 205 14.5 142 25 215 17.8 143 25 225 20.6 144 25 235 16.4 145 25 245 11.5 146 25 255 9.9 147 25 265 14.4 148 25 275 11.2 149 25 285 11.7 150 25 295 11.8 151 25 305 12.4 152 25 315 14.0 153 25 325 13.3 154 25 335 11.9 155 25 345 7.7 160 15 35 4.5 161 15 45 7.1 162 15 55 4.0 163 15 65 3.0 164 15 75 6.9 165 15 85 7.8 166 15 95 5.8 167 15 105 12.6 168 15 115 6.7 169 15 125 8.3 170 15 135 8.1 171 15 145 9.0 172 15 155 9.9 173 15 165 11.8 174 15 175 12.2 175 15 185 13.4 176 15 195 16.6 177 15 205 19.1 178 15 215 20.2 179 15 225 24.4 180 15 235 24.7 181 15 245 15.8 182 15 255 8.7 183 15 265 8.8 184 15 275 10.7 185 15 285 10.7 186 15 295 10.6 187 15 305 11.7 188 15 315 13.5 189 15 325 12.5 190 15 335 9.8 191 15 345 6.8 193 5 5 23.3 197 5 45 7.4 198 5 55 6.2 199 5 65 6.8 200 5 75 13.6 201 5 85 20.4 202 5 95 25.9 203 5 105 13.7 204 5 115 13.3 205 5 125 14.0 206 5 135 16.7 207 5 145 17.3 208 5 155 22.7 209 5 165 22.4 210 5 175 17.2 211 5 185 24.4 212 5 195 23.7 213 5 205 23.1 214 5 215 19.8 215 5 225 19.1 216 5 235 15.2 217 5 245 15.0 218 5 255 14.9 219 5 265 16.7 220 5 275 23.4 221 5 285 21.7 223 5 305 16.9 224 5 315 22.7 225 5 325 20.6 226 5 335 16.8 227 5 345 16.7 228 5 355 22.0 229 -5 5 21.2 230 -5 15 18.1 232 -5 35 8.4 233 -5 45 11.9 234 -5 55 9.0 235 -5 65 13.9 236 -5 75 16.9 237 -5 85 21.6 238 -5 95 23.9 239 -5 105 25.3 240 -5 115 22.7 241 -5 125 18.9 242 -5 135 23.0 243 -5 145 28.6 244 -5 155 24.4 245 -5 165 22.3 246 -5 175 18.7 247 -5 185 16.6 248 -5 195 13.8 249 -5 205 9.8 250 -5 215 12.6 251 -5 225 8.7 252 -5 235 12.5 253 -5 245 14.2 254 -5 255 15.5 255 -5 265 16.1 256 -5 275 21.7 257 -5 285 19.6 260 -5 315 30.6 261 -5 325 19.9 262 -5 335 14.4 263 -5 345 10.9 264 -5 355 14.1 265 -15 5 13.1 266 -15 15 27.1 268 -15 35 9.4 269 -15 45 14.2 270 -15 55 13.6 271 -15 65 14.0 272 -15 75 15.2 273 -15 85 17.9 274 -15 95 19.7 275 -15 105 14.6 276 -15 115 9.5 277 -15 125 9.9 278 -15 135 19.4 279 -15 145 18.2 280 -15 155 18.0 281 -15 165 18.1 282 -15 175 22.0 283 -15 185 22.6 284 -15 195 16.7 285 -15 205 14.9 286 -15 215 11.5 287 -15 225 11.0 288 -15 235 11.0 289 -15 245 12.8 290 -15 255 16.9 291 -15 265 17.4 292 -15 275 16.7 293 -15 285 16.6 297 -15 325 15.9 298 -15 335 10.6 299 -15 345 11.2 300 -15 355 13.8 301 -25 5 12.7 302 -25 15 12.3 304 -25 35 11.1 305 -25 45 13.9 306 -25 55 16.2 307 -25 65 16.1 308 -25 75 16.0 309 -25 85 14.8 310 -25 95 17.8 311 -25 105 17.8 312 -25 115 13.3 315 -25 145 15.2 316 -25 155 13.6 317 -25 165 15.7 318 -25 175 19.2 319 -25 185 19.8 320 -25 195 22.7 321 -25 205 24.6 322 -25 215 21.3 323 -25 225 16.1 324 -25 235 15.9 325 -25 245 13.5 326 -25 255 19.9 327 -25 265 19.4 328 -25 275 16.8 329 -25 285 20.4 332 -25 315 21.1 333 -25 325 17.3 334 -25 335 16.0 335 -25 345 12.8 336 -25 355 16.1 337 -35 5 19.5 338 -35 15 13.0 339 -35 25 14.6 340 -35 35 13.9 341 -35 45 15.3 342 -35 55 19.4 343 -35 65 20.8 344 -35 75 20.1 345 -35 85 19.4 346 -35 95 19.4 347 -35 105 18.5 348 -35 115 17.6 349 -35 125 19.2 350 -35 135 19.9 351 -35 145 17.6 352 -35 155 15.4 353 -35 165 16.6 354 -35 175 17.1 355 -35 185 16.2 356 -35 195 19.2 357 -35 205 19.8 358 -35 215 20.7 359 -35 225 19.9 360 -35 235 16.0 361 -35 245 21.0 362 -35 255 21.5 363 -35 265 18.1 364 -35 275 13.9 365 -35 285 12.4 367 -35 305 13.7 368 -35 315 19.5 369 -35 325 16.9 370 -35 335 17.3 371 -35 345 21.2 372 -35 355 19.3 373 -45 5 16.6 374 -45 15 28.5 375 -45 25 24.1 376 -45 35 25.4 377 -45 45 24.5 378 -45 55 19.2 379 -45 65 19.6 380 -45 75 18.3 381 -45 85 29.7 382 -45 95 21.7 383 -45 105 20.1 384 -45 115 24.8 385 -45 125 21.6 386 -45 135 24.9 387 -45 145 18.0 388 -45 155 16.0 389 -45 165 15.7 390 -45 175 17.4 391 -45 185 20.5 392 -45 195 18.8 393 -45 205 15.0 394 -45 215 18.6 395 -45 225 23.8 396 -45 235 22.5 397 -45 245 12.2 398 -45 255 7.4 399 -45 265 14.3 400 -45 275 12.9 401 -45 285 12.2 402 -45 295 12.8 403 -45 305 18.6 404 -45 315 18.0 405 -45 325 22.3 406 -45 335 17.8 407 -45 345 24.0 408 -45 355 17.5 409 -55 10 22.9 410 -55 30 17.0 411 -55 50 18.6 412 -55 70 19.6 413 -55 90 24.8 416 -55 150 19.6 417 -55 170 23.2 421 -55 250 28.5 422 -55 270 19.3 423 -55 290 18.2 424 -55 310 24.8 425 -55 330 26.9 426 -55 350 14.5 427 -65 10 24.5 428 -65 30 20.5 429 -65 50 21.8 430 -65 70 16.5 431 -65 90 18.1 432 -65 110 29.4 433 -65 130 14.3 434 -65 150 27.6 435 -65 170 15.5 441 -65 290 10.9 442 -65 310 29.6 443 -65 330 7.4 444 -65 350 19.4