Altocumulus Average Cloud Amount (%) June, July, August (1954 - 1997) Night, Ship Observations Only Global Average: 16.6 Zonal Averages 15 zones Lat.N Average 85 17.5 75 19.2 65 21.1 55 18.3 45 18.1 35 15.7 25 13.7 15 17.9 5 23.4 -5 16.0 -15 15.4 -25 15.4 -35 14.3 -45 13.8 -55 16.3 Grid Box Averages 343 filled boxes Box # Lat.N Lon.E Average 1 85 60 22.3 2 85 180 14.0 3 85 300 15.9 4 75 20 22.2 5 75 60 18.6 6 75 100 18.4 7 75 140 16.7 8 75 180 17.2 9 75 220 18.0 10 75 260 22.4 11 75 300 19.8 12 75 340 22.4 13 65 10 23.2 14 65 30 16.9 15 65 50 16.7 16 65 70 12.2 20 65 150 12.0 21 65 170 12.2 22 65 190 18.4 23 65 210 19.0 24 65 230 27.4 25 65 250 24.6 26 65 270 23.1 27 65 290 20.3 28 65 310 21.1 29 65 330 22.2 30 65 350 23.6 31 55 10 19.8 32 55 30 15.5 37 55 130 9.3 38 55 150 13.6 39 55 170 14.0 40 55 190 18.2 41 55 210 20.1 42 55 230 19.9 44 55 270 18.1 45 55 290 22.0 46 55 310 17.5 47 55 330 20.9 48 55 350 21.9 49 45 5 10.1 50 45 15 8.5 51 45 25 8.4 52 45 35 7.0 53 45 45 9.2 54 45 55 8.7 62 45 135 15.6 63 45 145 13.5 64 45 155 16.1 65 45 165 15.9 66 45 175 17.8 67 45 185 20.9 68 45 195 21.0 69 45 205 23.1 70 45 215 23.2 71 45 225 20.7 72 45 235 12.7 77 45 285 16.1 78 45 295 16.5 79 45 305 18.4 80 45 315 18.2 81 45 325 18.1 82 45 335 20.6 83 45 345 18.5 84 45 355 17.3 85 35 5 8.8 86 35 15 4.7 87 35 25 2.4 88 35 35 1.9 96 35 115 15.6 97 35 125 19.8 98 35 135 19.8 99 35 145 19.3 100 35 155 18.3 101 35 165 20.4 102 35 175 18.4 103 35 185 20.2 104 35 195 19.0 105 35 205 19.8 106 35 215 20.1 107 35 225 16.4 108 35 235 10.6 109 35 245 6.7 112 35 275 14.7 113 35 285 17.9 114 35 295 17.1 115 35 305 13.6 116 35 315 12.8 117 35 325 13.4 118 35 335 15.6 119 35 345 11.7 120 35 355 8.7 124 25 35 4.0 125 25 45 3.0 126 25 55 7.7 127 25 65 17.5 128 25 75 19.7 129 25 85 25.5 130 25 95 28.9 131 25 105 21.2 132 25 115 17.3 133 25 125 15.1 134 25 135 17.2 135 25 145 14.2 136 25 155 14.2 137 25 165 13.7 138 25 175 13.0 139 25 185 11.5 140 25 195 11.0 141 25 205 12.3 142 25 215 17.1 143 25 225 20.6 144 25 235 17.6 145 25 245 12.5 146 25 255 17.9 147 25 265 13.3 148 25 275 14.3 149 25 285 15.3 150 25 295 12.2 151 25 305 8.8 152 25 315 9.6 153 25 325 12.0 154 25 335 11.9 155 25 345 9.7 160 15 35 15.4 161 15 45 17.7 162 15 55 11.9 163 15 65 18.3 164 15 75 25.3 165 15 85 26.0 166 15 95 32.6 167 15 105 26.0 168 15 115 19.5 169 15 125 17.0 170 15 135 17.9 171 15 145 15.5 172 15 155 14.1 173 15 165 11.2 174 15 175 12.7 175 15 185 13.8 176 15 195 13.4 177 15 205 15.6 178 15 215 17.5 179 15 225 21.1 180 15 235 24.2 181 15 245 19.7 182 15 255 26.2 183 15 265 29.9 184 15 275 22.9 185 15 285 15.7 186 15 295 11.2 187 15 305 11.0 188 15 315 14.5 189 15 325 17.8 190 15 335 18.8 191 15 345 17.2 193 5 5 33.2 197 5 45 10.6 198 5 55 8.9 199 5 65 14.3 200 5 75 22.8 201 5 85 25.7 202 5 95 36.4 203 5 105 27.6 204 5 115 23.6 205 5 125 26.1 206 5 135 35.3 207 5 145 21.6 208 5 155 20.9 209 5 165 17.0 210 5 175 21.5 211 5 185 22.8 212 5 195 22.0 213 5 205 20.9 214 5 215 17.6 215 5 225 18.3 216 5 235 22.2 217 5 245 24.2 218 5 255 25.1 219 5 265 30.8 220 5 275 37.7 221 5 285 34.7 223 5 305 19.6 224 5 315 21.4 225 5 325 18.7 226 5 335 23.8 227 5 345 26.6 228 5 355 26.4 229 -5 5 20.8 230 -5 15 14.3 232 -5 35 11.6 233 -5 45 11.7 234 -5 55 14.7 235 -5 65 20.9 236 -5 75 21.0 237 -5 85 25.8 238 -5 95 25.8 239 -5 105 20.8 240 -5 115 15.4 241 -5 125 17.6 242 -5 135 22.4 243 -5 145 25.9 244 -5 155 22.7 245 -5 165 20.5 246 -5 175 14.2 247 -5 185 14.5 248 -5 195 10.7 249 -5 205 7.3 250 -5 215 7.4 251 -5 225 7.2 252 -5 235 8.0 253 -5 245 10.2 254 -5 255 17.3 255 -5 265 21.7 256 -5 275 23.4 257 -5 285 17.4 260 -5 315 14.8 261 -5 325 11.9 262 -5 335 11.1 263 -5 345 10.5 264 -5 355 12.5 265 -15 5 16.4 266 -15 15 30.3 268 -15 35 8.1 269 -15 45 10.9 270 -15 55 14.8 271 -15 65 15.7 272 -15 75 17.5 273 -15 85 17.2 274 -15 95 21.0 275 -15 105 15.2 276 -15 115 9.3 277 -15 125 4.4 278 -15 135 12.4 279 -15 145 14.0 280 -15 155 17.6 281 -15 165 20.2 282 -15 175 20.6 283 -15 185 17.5 284 -15 195 13.7 285 -15 205 15.0 286 -15 215 11.6 287 -15 225 11.8 288 -15 235 10.5 289 -15 245 11.6 290 -15 255 14.6 291 -15 265 18.2 292 -15 275 16.9 293 -15 285 20.3 297 -15 325 13.8 298 -15 335 12.6 299 -15 345 18.0 300 -15 355 18.2 301 -25 5 12.5 302 -25 15 9.0 304 -25 35 7.0 305 -25 45 11.0 306 -25 55 13.3 307 -25 65 16.2 308 -25 75 15.3 309 -25 85 15.9 310 -25 95 16.0 311 -25 105 16.8 312 -25 115 10.7 315 -25 145 8.2 316 -25 155 11.5 317 -25 165 15.7 318 -25 175 18.3 319 -25 185 18.3 320 -25 195 17.3 321 -25 205 22.9 322 -25 215 16.1 323 -25 225 15.2 324 -25 235 14.5 325 -25 245 14.6 326 -25 255 16.1 327 -25 265 17.5 328 -25 275 10.3 329 -25 285 14.8 332 -25 315 17.3 333 -25 325 16.4 334 -25 335 16.6 335 -25 345 16.8 336 -25 355 18.9 337 -35 5 18.7 338 -35 15 10.5 339 -35 25 9.7 340 -35 35 9.0 341 -35 45 13.5 342 -35 55 16.5 343 -35 65 14.9 344 -35 75 14.8 345 -35 85 12.9 346 -35 95 12.2 347 -35 105 13.1 348 -35 115 13.6 349 -35 125 15.7 350 -35 135 15.7 351 -35 145 15.8 352 -35 155 13.2 353 -35 165 13.2 354 -35 175 11.9 355 -35 185 13.7 356 -35 195 14.1 357 -35 205 15.8 358 -35 215 14.2 359 -35 225 15.5 360 -35 235 20.7 363 -35 265 8.8 364 -35 275 7.5 365 -35 285 12.9 367 -35 305 13.5 368 -35 315 15.1 369 -35 325 19.3 370 -35 335 14.7 371 -35 345 18.9 372 -35 355 20.4 377 -45 45 17.3 379 -45 65 18.0 380 -45 75 16.4 386 -45 135 14.4 387 -45 145 16.6 388 -45 155 15.9 389 -45 165 15.3 390 -45 175 12.5 391 -45 185 8.5 392 -45 195 20.4 393 -45 205 14.4 394 -45 215 14.1 396 -45 235 10.3 397 -45 245 8.6 398 -45 255 4.4 400 -45 275 9.5 401 -45 285 15.7 402 -45 295 13.8 403 -45 305 14.0 404 -45 315 11.3 405 -45 325 18.9 417 -55 170 19.3 422 -55 270 14.0 423 -55 290 12.3 424 -55 310 19.6 425 -55 330 15.6