Altocumulus Average Cloud Amount (%) September (1954 - 1997) Day, Ship Observations Only Global Average: 17.2 Zonal Averages 15 zones Lat.N Average 85 18.5 75 17.4 65 19.6 55 18.5 45 17.5 35 15.2 25 13.1 15 18.0 5 22.4 -5 15.9 -15 15.0 -25 15.7 -35 16.8 -45 16.5 -55 21.3 Grid Box Averages 346 filled boxes Box # Lat.N Lon.E Average 1 85 60 16.4 2 85 180 18.6 3 85 300 21.1 4 75 20 22.2 5 75 60 19.1 6 75 100 17.5 7 75 140 15.7 8 75 180 14.4 9 75 220 13.7 10 75 260 19.5 11 75 300 18.3 12 75 340 19.1 13 65 10 22.2 14 65 30 17.0 15 65 50 14.8 16 65 70 23.1 20 65 150 9.8 21 65 170 13.5 22 65 190 17.5 23 65 210 14.4 25 65 250 27.5 26 65 270 21.6 27 65 290 21.1 28 65 310 18.5 29 65 330 19.6 30 65 350 20.5 31 55 10 20.0 32 55 30 21.1 37 55 130 9.6 38 55 150 13.0 39 55 170 15.8 40 55 190 18.1 41 55 210 18.9 42 55 230 18.2 44 55 270 31.1 45 55 290 20.8 46 55 310 18.4 47 55 330 19.2 48 55 350 20.7 49 45 5 13.0 50 45 15 12.6 51 45 25 10.1 52 45 35 6.6 53 45 45 7.9 54 45 55 6.5 62 45 135 11.4 63 45 145 12.7 64 45 155 15.8 65 45 165 17.9 66 45 175 18.9 67 45 185 19.7 68 45 195 20.6 69 45 205 20.3 70 45 215 20.6 71 45 225 17.8 72 45 235 13.8 77 45 285 15.6 78 45 295 14.9 79 45 305 17.6 80 45 315 18.8 81 45 325 19.0 82 45 335 19.2 83 45 345 18.1 84 45 355 17.1 85 35 5 10.8 86 35 15 8.2 87 35 25 3.6 88 35 35 2.2 90 35 55 4.7 96 35 115 14.7 97 35 125 18.8 98 35 135 20.6 99 35 145 19.3 100 35 155 17.3 101 35 165 15.6 102 35 175 16.2 103 35 185 18.4 104 35 195 17.3 105 35 205 17.1 106 35 215 17.4 107 35 225 15.5 108 35 235 11.4 109 35 245 7.7 112 35 275 16.6 113 35 285 17.2 114 35 295 16.4 115 35 305 16.0 116 35 315 14.7 117 35 325 13.9 118 35 335 14.3 119 35 345 11.4 120 35 355 9.5 124 25 35 3.8 125 25 45 1.0 126 25 55 2.4 127 25 65 7.5 128 25 75 12.3 129 25 85 22.3 130 25 95 32.9 131 25 105 23.2 132 25 115 19.8 133 25 125 15.6 134 25 135 13.9 135 25 145 12.9 136 25 155 12.6 137 25 165 13.1 138 25 175 12.1 139 25 185 11.8 140 25 195 10.2 141 25 205 11.3 142 25 215 14.3 143 25 225 18.2 144 25 235 16.6 145 25 245 10.8 146 25 255 17.1 147 25 265 18.3 148 25 275 19.8 149 25 285 15.6 150 25 295 13.2 151 25 305 12.1 152 25 315 11.2 153 25 325 10.8 154 25 335 10.4 155 25 345 8.8 160 15 35 6.4 161 15 45 7.3 162 15 55 7.4 163 15 65 13.8 164 15 75 21.9 165 15 85 18.8 166 15 95 30.2 167 15 105 24.7 168 15 115 22.9 169 15 125 21.1 170 15 135 21.6 171 15 145 20.1 172 15 155 18.9 173 15 165 16.5 174 15 175 15.4 175 15 185 14.7 176 15 195 14.9 177 15 205 15.4 178 15 215 16.2 179 15 225 18.8 180 15 235 19.2 181 15 245 20.7 182 15 255 26.8 183 15 265 31.9 184 15 275 23.7 185 15 285 16.4 186 15 295 12.7 187 15 305 13.3 188 15 315 13.8 189 15 325 15.6 190 15 335 15.6 191 15 345 18.2 193 5 5 29.4 197 5 45 7.8 198 5 55 7.6 199 5 65 15.8 200 5 75 21.4 201 5 85 26.4 202 5 95 36.9 203 5 105 30.2 204 5 115 31.5 205 5 125 23.9 206 5 135 24.5 207 5 145 22.6 208 5 155 22.6 209 5 165 21.8 210 5 175 23.1 211 5 185 16.6 212 5 195 19.8 213 5 205 21.6 214 5 215 18.7 215 5 225 18.4 216 5 235 18.6 217 5 245 22.1 218 5 255 27.9 219 5 265 27.9 220 5 275 34.5 221 5 285 36.5 223 5 305 15.0 224 5 315 15.4 225 5 325 14.1 226 5 335 21.6 227 5 345 28.3 228 5 355 25.5 229 -5 5 23.2 230 -5 15 34.2 232 -5 35 9.0 233 -5 45 8.8 234 -5 55 12.7 235 -5 65 24.4 236 -5 75 26.2 237 -5 85 33.4 238 -5 95 29.5 239 -5 105 22.0 240 -5 115 13.1 241 -5 125 12.4 242 -5 135 15.9 243 -5 145 24.9 244 -5 155 23.0 245 -5 165 20.6 246 -5 175 17.1 247 -5 185 10.4 248 -5 195 9.1 249 -5 205 6.3 250 -5 215 5.3 251 -5 225 5.8 252 -5 235 7.2 253 -5 245 10.6 254 -5 255 17.2 255 -5 265 17.7 256 -5 275 17.7 260 -5 315 7.5 261 -5 325 8.6 262 -5 335 8.8 263 -5 345 13.4 264 -5 355 16.9 265 -15 5 21.5 266 -15 15 34.9 268 -15 35 5.7 269 -15 45 7.3 270 -15 55 12.9 271 -15 65 15.1 272 -15 75 17.7 273 -15 85 20.6 274 -15 95 18.6 275 -15 105 12.6 276 -15 115 6.0 277 -15 125 4.3 278 -15 135 6.9 279 -15 145 9.4 280 -15 155 13.5 281 -15 165 18.1 282 -15 175 20.4 283 -15 185 17.2 284 -15 195 16.1 285 -15 205 13.1 286 -15 215 11.7 287 -15 225 10.4 288 -15 235 11.8 289 -15 245 13.1 290 -15 255 17.0 291 -15 265 15.2 292 -15 275 16.3 293 -15 285 15.8 297 -15 325 14.7 298 -15 335 14.2 299 -15 345 18.6 300 -15 355 22.9 301 -25 5 13.2 302 -25 15 16.3 304 -25 35 9.4 305 -25 45 9.2 306 -25 55 11.4 307 -25 65 14.0 308 -25 75 14.4 309 -25 85 14.1 310 -25 95 16.2 311 -25 105 15.6 312 -25 115 7.8 315 -25 145 6.2 316 -25 155 9.2 317 -25 165 12.8 318 -25 175 17.0 319 -25 185 17.2 320 -25 195 20.1 321 -25 205 21.6 322 -25 215 18.6 323 -25 225 17.5 324 -25 235 17.3 325 -25 245 16.9 326 -25 255 13.4 327 -25 265 17.8 328 -25 275 14.1 329 -25 285 10.1 332 -25 315 24.0 333 -25 325 19.9 334 -25 335 17.7 335 -25 345 19.8 336 -25 355 19.1 337 -35 5 19.1 338 -35 15 13.5 339 -35 25 14.8 340 -35 35 14.2 341 -35 45 14.4 342 -35 55 15.5 343 -35 65 15.3 344 -35 75 16.1 345 -35 85 18.1 346 -35 95 15.8 347 -35 105 17.8 348 -35 115 16.1 349 -35 125 18.3 350 -35 135 17.9 351 -35 145 18.1 352 -35 155 14.3 353 -35 165 17.2 354 -35 175 16.8 355 -35 185 16.6 356 -35 195 18.5 357 -35 205 18.4 358 -35 215 21.7 359 -35 225 19.7 360 -35 235 14.6 361 -35 245 18.5 363 -35 265 15.4 364 -35 275 10.9 365 -35 285 10.4 367 -35 305 16.2 368 -35 315 18.2 369 -35 325 19.1 370 -35 335 18.1 371 -35 345 18.4 372 -35 355 22.3 376 -45 35 17.6 378 -45 55 19.2 379 -45 65 16.0 380 -45 75 7.6 384 -45 115 15.7 385 -45 125 16.2 386 -45 135 17.7 387 -45 145 14.0 388 -45 155 17.7 389 -45 165 19.6 390 -45 175 17.5 391 -45 185 14.7 392 -45 195 18.2 393 -45 205 18.5 394 -45 215 13.7 400 -45 275 4.3 401 -45 285 14.3 402 -45 295 16.1 403 -45 305 20.0 404 -45 315 24.5 405 -45 325 11.5 408 -45 355 26.6 411 -55 50 18.4 412 -55 70 15.3 417 -55 170 23.5 422 -55 270 11.5 423 -55 290 21.1 424 -55 310 26.6 425 -55 330 32.9