Altocumulus Average Cloud Amount (%) May (1954 - 1997) , Ship Observations Only Global Average: 17.3 Zonal Averages 16 zones Lat.N Average 85 11.2 75 13.2 65 17.4 55 16.3 45 16.7 35 16.9 25 14.3 15 14.4 5 21.7 -5 15.2 -15 14.7 -25 16.6 -35 17.1 -45 16.1 -55 17.5 -65 36.5 Grid Box Averages 356 filled boxes Box # Lat.N Lon.E Average 1 85 60 17.4 2 85 180 6.9 3 85 300 8.8 4 75 20 20.0 5 75 60 17.6 6 75 100 9.9 7 75 140 7.6 8 75 180 6.9 9 75 220 8.6 10 75 260 19.8 11 75 300 17.8 12 75 340 17.4 13 65 10 20.5 14 65 30 15.8 15 65 50 15.8 20 65 150 10.8 21 65 170 11.0 22 65 190 13.9 23 65 210 16.5 27 65 290 14.2 29 65 330 19.8 30 65 350 19.6 31 55 10 15.8 32 55 30 16.4 37 55 130 10.3 38 55 150 11.6 39 55 170 14.6 40 55 190 16.8 41 55 210 17.1 42 55 230 16.5 45 55 290 9.5 46 55 310 16.8 47 55 330 19.1 48 55 350 18.7 49 45 5 15.0 50 45 15 14.4 51 45 25 11.6 52 45 35 7.8 53 45 45 11.8 54 45 55 8.6 62 45 135 11.8 63 45 145 12.4 64 45 155 13.0 65 45 165 14.7 66 45 175 17.6 67 45 185 19.0 68 45 195 18.6 69 45 205 19.4 70 45 215 18.6 71 45 225 17.4 72 45 235 13.6 77 45 285 15.8 78 45 295 15.4 79 45 305 16.1 80 45 315 18.1 81 45 325 18.8 82 45 335 20.0 83 45 345 17.8 84 45 355 17.1 85 35 5 13.8 86 35 15 11.6 87 35 25 9.0 88 35 35 7.6 90 35 55 8.2 96 35 115 14.6 97 35 125 16.3 98 35 135 17.3 99 35 145 14.8 100 35 155 16.3 101 35 165 19.2 102 35 175 18.7 103 35 185 22.2 104 35 195 21.7 105 35 205 21.1 106 35 215 21.0 107 35 225 17.7 108 35 235 11.6 109 35 245 8.0 112 35 275 12.5 113 35 285 16.2 114 35 295 16.4 115 35 305 16.7 116 35 315 17.2 117 35 325 17.1 118 35 335 17.9 119 35 345 14.1 120 35 355 12.3 124 25 35 4.5 125 25 45 6.8 126 25 55 3.3 127 25 65 3.2 128 25 75 4.6 129 25 85 14.3 130 25 95 16.6 131 25 105 18.2 132 25 115 20.2 133 25 125 20.3 134 25 135 18.6 135 25 145 15.8 136 25 155 13.3 137 25 165 12.5 138 25 175 12.9 139 25 185 13.3 140 25 195 13.2 141 25 205 13.2 142 25 215 17.0 143 25 225 22.0 144 25 235 19.1 145 25 245 12.5 146 25 255 9.4 147 25 265 13.2 148 25 275 12.2 149 25 285 14.9 150 25 295 15.5 151 25 305 14.8 152 25 315 13.5 153 25 325 12.8 154 25 335 11.9 155 25 345 8.7 160 15 35 5.8 161 15 45 6.5 162 15 55 4.3 163 15 65 5.5 164 15 75 10.8 165 15 85 14.3 166 15 95 19.4 167 15 105 18.6 168 15 115 11.4 169 15 125 10.7 170 15 135 9.4 171 15 145 8.5 172 15 155 10.3 173 15 165 14.0 174 15 175 14.4 175 15 185 15.1 176 15 195 16.4 177 15 205 16.7 178 15 215 22.6 179 15 225 27.6 180 15 235 25.5 181 15 245 14.8 182 15 255 11.5 183 15 265 17.4 184 15 275 17.9 185 15 285 16.4 186 15 295 15.4 187 15 305 13.3 188 15 315 15.3 189 15 325 13.7 190 15 335 11.8 191 15 345 10.4 193 5 5 28.0 197 5 45 10.6 198 5 55 11.8 199 5 65 14.2 200 5 75 20.1 201 5 85 24.3 202 5 95 33.6 203 5 105 19.7 204 5 115 19.8 205 5 125 18.9 206 5 135 21.9 207 5 145 21.7 208 5 155 20.9 209 5 165 24.4 210 5 175 25.4 211 5 185 19.5 212 5 195 22.8 213 5 205 20.8 214 5 215 18.6 215 5 225 20.6 216 5 235 15.2 217 5 245 24.9 218 5 255 18.4 219 5 265 24.4 220 5 275 33.2 221 5 285 29.6 223 5 305 19.3 224 5 315 23.3 225 5 325 21.4 226 5 335 21.5 227 5 345 23.5 228 5 355 26.9 229 -5 5 17.3 230 -5 15 14.6 232 -5 35 21.1 233 -5 45 12.8 234 -5 55 12.6 235 -5 65 15.4 236 -5 75 19.0 237 -5 85 24.7 238 -5 95 24.5 239 -5 105 22.4 240 -5 115 19.3 241 -5 125 17.6 242 -5 135 22.8 243 -5 145 26.5 244 -5 155 23.2 245 -5 165 19.5 246 -5 175 14.7 247 -5 185 13.8 248 -5 195 10.2 249 -5 205 9.1 250 -5 215 9.9 251 -5 225 6.6 252 -5 235 7.8 253 -5 245 7.7 254 -5 255 11.0 255 -5 265 13.7 256 -5 275 19.6 257 -5 285 23.5 260 -5 315 23.2 261 -5 325 17.6 262 -5 335 11.4 263 -5 345 11.0 264 -5 355 12.9 265 -15 5 11.1 266 -15 15 27.0 268 -15 35 8.6 269 -15 45 9.8 270 -15 55 13.1 271 -15 65 13.4 272 -15 75 13.2 273 -15 85 16.7 274 -15 95 19.0 275 -15 105 16.8 276 -15 115 11.2 277 -15 125 8.0 278 -15 135 15.9 279 -15 145 17.3 280 -15 155 17.4 281 -15 165 19.2 282 -15 175 19.4 283 -15 185 20.0 284 -15 195 20.6 285 -15 205 16.2 286 -15 215 9.8 287 -15 225 10.0 288 -15 235 11.0 289 -15 245 10.4 290 -15 255 13.0 291 -15 265 15.5 292 -15 275 18.5 293 -15 285 21.3 297 -15 325 15.3 298 -15 335 9.5 299 -15 345 12.2 300 -15 355 13.0 301 -25 5 10.2 302 -25 15 9.6 304 -25 35 8.8 305 -25 45 11.8 306 -25 55 15.8 307 -25 65 13.4 308 -25 75 14.0 309 -25 85 16.6 310 -25 95 17.6 311 -25 105 16.8 312 -25 115 12.2 315 -25 145 15.8 316 -25 155 14.5 317 -25 165 17.6 318 -25 175 19.7 319 -25 185 20.2 320 -25 195 22.3 321 -25 205 23.0 322 -25 215 20.1 323 -25 225 18.6 324 -25 235 17.9 325 -25 245 16.5 326 -25 255 19.0 327 -25 265 13.4 328 -25 275 11.2 329 -25 285 17.9 332 -25 315 20.5 333 -25 325 17.9 334 -25 335 18.2 335 -25 345 16.6 336 -25 355 16.3 337 -35 5 19.4 338 -35 15 12.1 339 -35 25 13.3 340 -35 35 11.7 341 -35 45 15.2 342 -35 55 18.1 343 -35 65 17.5 344 -35 75 15.0 345 -35 85 15.9 346 -35 95 15.4 347 -35 105 15.7 348 -35 115 16.8 349 -35 125 18.4 350 -35 135 19.6 351 -35 145 20.2 352 -35 155 16.3 353 -35 165 15.4 354 -35 175 15.5 355 -35 185 17.0 356 -35 195 14.9 357 -35 205 18.0 358 -35 215 21.9 359 -35 225 20.1 360 -35 235 24.4 361 -35 245 19.6 362 -35 255 16.0 363 -35 265 21.8 364 -35 275 13.2 365 -35 285 12.2 367 -35 305 15.1 368 -35 315 19.0 369 -35 325 19.1 370 -35 335 15.9 371 -35 345 18.5 372 -35 355 20.2 374 -45 15 23.2 375 -45 25 35.5 376 -45 35 14.4 377 -45 45 18.4 378 -45 55 18.1 379 -45 65 25.1 380 -45 75 11.2 384 -45 115 8.9 385 -45 125 16.8 386 -45 135 23.2 387 -45 145 19.6 388 -45 155 15.0 389 -45 165 17.4 390 -45 175 13.2 391 -45 185 13.5 392 -45 195 13.1 393 -45 205 11.9 394 -45 215 11.7 395 -45 225 16.4 396 -45 235 13.0 397 -45 245 9.3 398 -45 255 8.5 399 -45 265 8.6 400 -45 275 9.5 401 -45 285 11.9 402 -45 295 17.0 403 -45 305 14.6 404 -45 315 16.8 405 -45 325 23.0 406 -45 335 15.9 407 -45 345 24.1 411 -55 50 18.6 412 -55 70 27.8 417 -55 170 24.6 419 -55 210 5.6 420 -55 230 15.3 421 -55 250 15.4 422 -55 270 11.8 423 -55 290 15.3 424 -55 310 22.8 425 -55 330 17.8 442 -65 310 36.5