Altocumulus Average Cloud Amount (%) September (1954 - 1997) , Ship Observations Only Global Average: 17.0 Zonal Averages 15 zones Lat.N Average 85 17.5 75 16.5 65 18.7 55 17.4 45 16.8 35 14.6 25 12.9 15 17.4 5 22.3 -5 16.0 -15 15.7 -25 16.2 -35 16.4 -45 16.4 -55 20.1 Grid Box Averages 350 filled boxes Box # Lat.N Lon.E Average 1 85 60 17.0 2 85 180 16.4 3 85 300 19.9 4 75 20 21.2 5 75 60 18.1 6 75 100 16.9 7 75 140 13.2 8 75 180 13.6 9 75 220 14.5 10 75 260 19.0 11 75 300 16.7 12 75 340 17.4 13 65 10 21.3 14 65 30 16.2 15 65 50 14.9 16 65 70 20.6 20 65 150 11.2 21 65 170 12.5 22 65 190 17.8 23 65 210 16.2 25 65 250 26.8 26 65 270 20.1 27 65 290 20.1 28 65 310 17.5 29 65 330 18.4 30 65 350 19.1 31 55 10 19.7 32 55 30 21.4 37 55 130 10.2 38 55 150 11.7 39 55 170 14.6 40 55 190 18.1 41 55 210 17.4 42 55 230 16.7 44 55 270 27.8 45 55 290 20.0 46 55 310 17.7 47 55 330 17.9 48 55 350 19.1 49 45 5 12.6 50 45 15 11.3 51 45 25 11.9 52 45 35 6.5 53 45 45 12.4 54 45 55 6.7 62 45 135 10.3 63 45 145 11.6 64 45 155 15.0 65 45 165 17.5 66 45 175 18.8 67 45 185 20.3 68 45 195 20.2 69 45 205 19.9 70 45 215 19.4 71 45 225 16.6 72 45 235 13.0 77 45 285 14.8 78 45 295 14.4 79 45 305 16.6 80 45 315 18.3 81 45 325 18.3 82 45 335 17.8 83 45 345 17.0 84 45 355 16.5 85 35 5 11.0 86 35 15 7.6 87 35 25 3.2 88 35 35 1.9 90 35 55 3.8 96 35 115 13.5 97 35 125 17.8 98 35 135 20.5 99 35 145 19.1 100 35 155 16.8 101 35 165 14.7 102 35 175 15.8 103 35 185 18.9 104 35 195 16.5 105 35 205 16.7 106 35 215 17.2 107 35 225 14.7 108 35 235 10.8 109 35 245 8.7 112 35 275 15.9 113 35 285 16.7 114 35 295 15.3 115 35 305 13.9 116 35 315 13.9 117 35 325 13.2 118 35 335 13.7 119 35 345 11.2 120 35 355 9.6 124 25 35 5.3 125 25 45 0.9 126 25 55 2.7 127 25 65 7.2 128 25 75 10.8 129 25 85 27.8 130 25 95 33.8 131 25 105 22.9 132 25 115 18.4 133 25 125 14.6 134 25 135 14.5 135 25 145 12.6 136 25 155 11.8 137 25 165 12.1 138 25 175 11.6 139 25 185 11.4 140 25 195 10.2 141 25 205 11.2 142 25 215 15.0 143 25 225 18.3 144 25 235 17.9 145 25 245 10.1 146 25 255 16.3 147 25 265 16.5 148 25 275 18.3 149 25 285 15.5 150 25 295 11.8 151 25 305 11.1 152 25 315 10.8 153 25 325 11.2 154 25 335 11.2 155 25 345 9.0 160 15 35 12.1 161 15 45 10.9 162 15 55 7.9 163 15 65 13.6 164 15 75 21.1 165 15 85 19.6 166 15 95 31.5 167 15 105 24.0 168 15 115 20.2 169 15 125 18.6 170 15 135 20.0 171 15 145 19.4 172 15 155 16.5 173 15 165 14.7 174 15 175 14.0 175 15 185 13.9 176 15 195 14.0 177 15 205 14.2 178 15 215 16.9 179 15 225 20.5 180 15 235 17.9 181 15 245 19.4 182 15 255 25.6 183 15 265 30.9 184 15 275 24.1 185 15 285 15.8 186 15 295 11.5 187 15 305 12.7 188 15 315 14.0 189 15 325 16.5 190 15 335 15.8 191 15 345 18.6 193 5 5 32.4 197 5 45 7.0 198 5 55 7.3 199 5 65 14.7 200 5 75 20.8 201 5 85 26.1 202 5 95 37.1 203 5 105 27.8 204 5 115 27.6 205 5 125 23.6 206 5 135 24.6 207 5 145 22.6 208 5 155 21.5 209 5 165 21.1 210 5 175 21.9 211 5 185 15.9 212 5 195 19.8 213 5 205 18.2 214 5 215 17.0 215 5 225 19.8 216 5 235 19.0 217 5 245 22.8 218 5 255 27.3 219 5 265 28.7 220 5 275 35.4 221 5 285 33.1 223 5 305 15.5 224 5 315 16.1 225 5 325 16.3 226 5 335 23.6 227 5 345 29.3 228 5 355 27.4 229 -5 5 27.7 230 -5 15 29.6 232 -5 35 10.3 233 -5 45 9.2 234 -5 55 14.5 235 -5 65 23.6 236 -5 75 24.2 237 -5 85 31.3 238 -5 95 28.1 239 -5 105 19.8 240 -5 115 11.1 241 -5 125 12.3 242 -5 135 16.1 243 -5 145 23.7 244 -5 155 22.6 245 -5 165 19.6 246 -5 175 15.4 247 -5 185 10.3 248 -5 195 9.1 249 -5 205 5.9 250 -5 215 6.3 251 -5 225 6.8 252 -5 235 6.8 253 -5 245 10.7 254 -5 255 18.8 255 -5 265 19.1 256 -5 275 20.8 257 -5 285 20.1 260 -5 315 8.5 261 -5 325 8.6 262 -5 335 9.4 263 -5 345 13.3 264 -5 355 17.8 265 -15 5 23.6 266 -15 15 34.8 268 -15 35 4.9 269 -15 45 6.2 270 -15 55 13.8 271 -15 65 18.1 272 -15 75 18.9 273 -15 85 21.4 274 -15 95 20.0 275 -15 105 11.7 276 -15 115 5.2 277 -15 125 4.2 278 -15 135 6.4 279 -15 145 10.6 280 -15 155 13.9 281 -15 165 18.8 282 -15 175 21.8 283 -15 185 18.4 284 -15 195 14.6 285 -15 205 12.5 286 -15 215 11.4 287 -15 225 8.8 288 -15 235 12.4 289 -15 245 15.7 290 -15 255 19.8 291 -15 265 17.9 292 -15 275 16.1 293 -15 285 14.4 297 -15 325 15.0 298 -15 335 16.2 299 -15 345 20.4 300 -15 355 23.1 301 -25 5 14.4 302 -25 15 14.7 304 -25 35 8.6 305 -25 45 9.4 306 -25 55 11.9 307 -25 65 17.6 308 -25 75 17.1 309 -25 85 16.3 310 -25 95 16.5 311 -25 105 15.2 312 -25 115 7.7 315 -25 145 4.1 316 -25 155 9.5 317 -25 165 13.2 318 -25 175 16.6 319 -25 185 17.1 320 -25 195 18.6 321 -25 205 23.3 322 -25 215 17.6 323 -25 225 15.7 324 -25 235 17.3 325 -25 245 17.7 326 -25 255 15.9 327 -25 265 19.8 328 -25 275 12.5 329 -25 285 9.4 332 -25 315 24.3 333 -25 325 19.6 334 -25 335 17.5 335 -25 345 19.4 336 -25 355 21.5 337 -35 5 19.8 338 -35 15 13.2 339 -35 25 13.8 340 -35 35 14.0 341 -35 45 14.4 342 -35 55 14.8 343 -35 65 15.4 344 -35 75 14.9 345 -35 85 17.1 346 -35 95 17.2 347 -35 105 18.3 348 -35 115 14.7 349 -35 125 16.9 350 -35 135 16.8 351 -35 145 17.3 352 -35 155 14.2 353 -35 165 14.6 354 -35 175 15.9 355 -35 185 16.6 356 -35 195 16.8 357 -35 205 16.9 358 -35 215 17.7 359 -35 225 21.3 360 -35 235 15.1 361 -35 245 17.9 362 -35 255 18.3 363 -35 265 16.7 364 -35 275 11.2 365 -35 285 10.1 367 -35 305 16.0 368 -35 315 17.6 369 -35 325 15.9 370 -35 335 18.1 371 -35 345 19.7 372 -35 355 20.6 373 -45 5 25.8 376 -45 35 17.0 377 -45 45 20.9 378 -45 55 16.8 379 -45 65 14.0 380 -45 75 8.6 384 -45 115 15.2 385 -45 125 15.6 386 -45 135 16.0 387 -45 145 11.8 388 -45 155 17.9 389 -45 165 18.6 390 -45 175 15.6 391 -45 185 18.2 392 -45 195 18.6 393 -45 205 20.1 394 -45 215 13.2 400 -45 275 7.5 401 -45 285 14.2 402 -45 295 17.2 403 -45 305 16.9 404 -45 315 19.6 405 -45 325 11.0 408 -45 355 23.3 411 -55 50 21.1 412 -55 70 14.0 417 -55 170 23.9 422 -55 270 15.7 423 -55 290 16.6 424 -55 310 25.5 425 -55 330 23.6