Altocumulus Average Cloud Amount (%) April (1954 - 1997) Night, Ship Observations Only Global Average: 15.8 Zonal Averages 16 zones Lat.N Average 85 10.2 75 11.5 65 14.8 55 12.4 45 14.0 35 15.7 25 13.7 15 12.0 5 17.6 -5 16.6 -15 15.0 -25 16.4 -35 16.8 -45 15.7 -55 22.6 -65 16.5 Grid Box Averages 314 filled boxes Box # Lat.N Lon.E Average 1 85 60 9.9 2 85 180 10.9 3 85 300 9.8 4 75 20 15.6 5 75 60 12.5 7 75 140 12.9 8 75 180 8.1 9 75 220 9.4 12 75 340 10.6 13 65 10 19.3 14 65 30 15.2 15 65 50 10.3 21 65 170 6.7 22 65 190 7.3 23 65 210 10.8 29 65 330 16.2 30 65 350 18.0 31 55 10 15.9 32 55 30 17.8 38 55 150 6.0 39 55 170 9.5 40 55 190 11.6 41 55 210 12.8 42 55 230 11.8 46 55 310 12.0 47 55 330 15.5 48 55 350 17.3 49 45 5 15.4 50 45 15 15.7 51 45 25 14.6 52 45 35 12.2 54 45 55 7.8 62 45 135 8.5 63 45 145 8.6 64 45 155 9.1 65 45 165 11.6 66 45 175 13.1 67 45 185 16.7 68 45 195 16.3 69 45 205 15.2 70 45 215 14.7 71 45 225 13.7 72 45 235 13.4 77 45 285 12.1 78 45 295 13.0 79 45 305 13.2 80 45 315 15.3 81 45 325 17.6 82 45 335 17.1 83 45 345 15.4 84 45 355 15.1 85 35 5 15.6 86 35 15 13.4 87 35 25 10.7 88 35 35 8.7 97 35 125 12.2 98 35 135 13.4 99 35 145 12.2 100 35 155 14.1 101 35 165 16.3 102 35 175 19.4 103 35 185 22.9 104 35 195 20.1 105 35 205 21.1 106 35 215 18.6 107 35 225 14.4 108 35 235 9.9 109 35 245 7.6 112 35 275 11.6 113 35 285 14.5 114 35 295 15.2 115 35 305 15.2 116 35 315 17.9 117 35 325 16.7 118 35 335 15.9 119 35 345 13.6 120 35 355 13.8 124 25 35 4.8 125 25 45 13.3 126 25 55 8.0 127 25 65 4.3 129 25 85 12.3 132 25 115 18.9 133 25 125 16.4 134 25 135 14.7 135 25 145 14.6 136 25 155 14.0 137 25 165 14.9 138 25 175 13.8 139 25 185 14.7 140 25 195 14.8 141 25 205 15.0 142 25 215 17.5 143 25 225 21.0 144 25 235 16.0 145 25 245 10.9 146 25 255 9.5 147 25 265 14.4 148 25 275 10.9 149 25 285 12.0 150 25 295 11.3 151 25 305 11.4 152 25 315 13.8 153 25 325 12.3 154 25 335 12.2 155 25 345 8.1 160 15 35 5.1 161 15 45 7.7 162 15 55 4.0 163 15 65 2.8 164 15 75 7.7 165 15 85 7.9 166 15 95 5.4 167 15 105 11.4 168 15 115 6.0 169 15 125 8.2 170 15 135 8.3 171 15 145 9.4 172 15 155 9.9 173 15 165 12.8 174 15 175 12.8 175 15 185 13.2 176 15 195 17.0 177 15 205 21.4 178 15 215 20.4 179 15 225 24.2 180 15 235 23.9 181 15 245 15.4 182 15 255 8.8 183 15 265 10.3 184 15 275 11.6 185 15 285 10.4 186 15 295 10.1 187 15 305 11.2 188 15 315 14.0 189 15 325 12.1 190 15 335 10.6 191 15 345 7.6 193 5 5 24.7 197 5 45 7.7 198 5 55 5.9 199 5 65 5.6 200 5 75 13.1 201 5 85 18.9 202 5 95 25.4 203 5 105 12.4 204 5 115 12.2 205 5 125 12.4 206 5 135 17.8 207 5 145 16.2 208 5 155 23.0 209 5 165 21.1 210 5 175 16.0 211 5 185 24.6 212 5 195 24.9 213 5 205 24.5 214 5 215 18.9 215 5 225 19.3 216 5 235 13.5 217 5 245 13.0 218 5 255 13.4 219 5 265 17.4 220 5 275 24.4 221 5 285 20.2 223 5 305 16.9 224 5 315 23.1 225 5 325 19.7 226 5 335 16.7 227 5 345 15.4 228 5 355 21.2 229 -5 5 22.9 230 -5 15 12.6 233 -5 45 11.7 234 -5 55 8.4 235 -5 65 12.8 236 -5 75 15.2 237 -5 85 19.9 238 -5 95 22.5 239 -5 105 24.1 240 -5 115 20.2 241 -5 125 19.0 242 -5 135 22.9 243 -5 145 29.1 244 -5 155 22.6 245 -5 165 21.4 246 -5 175 17.5 247 -5 185 16.9 248 -5 195 11.5 249 -5 205 10.2 250 -5 215 13.6 251 -5 225 7.3 252 -5 235 13.3 253 -5 245 15.2 254 -5 255 16.9 255 -5 265 16.1 256 -5 275 26.8 260 -5 315 28.6 261 -5 325 19.0 262 -5 335 13.8 263 -5 345 10.7 264 -5 355 14.0 265 -15 5 14.4 266 -15 15 26.2 268 -15 35 9.2 269 -15 45 13.9 270 -15 55 13.4 271 -15 65 14.6 272 -15 75 12.3 273 -15 85 16.2 274 -15 95 20.2 275 -15 105 14.2 276 -15 115 8.6 277 -15 125 9.8 278 -15 135 17.4 279 -15 145 17.6 280 -15 155 17.5 281 -15 165 17.6 282 -15 175 20.9 283 -15 185 22.6 284 -15 195 13.2 285 -15 205 12.3 286 -15 215 10.9 287 -15 225 11.6 288 -15 235 11.0 289 -15 245 13.2 290 -15 255 18.4 291 -15 265 18.6 292 -15 275 16.7 293 -15 285 17.0 297 -15 325 15.1 298 -15 335 11.1 299 -15 345 12.4 300 -15 355 15.3 301 -25 5 14.3 302 -25 15 11.8 304 -25 35 10.6 305 -25 45 13.8 306 -25 55 14.9 307 -25 65 15.5 308 -25 75 14.7 309 -25 85 14.4 310 -25 95 16.8 311 -25 105 16.9 312 -25 115 12.3 316 -25 155 12.9 317 -25 165 15.2 318 -25 175 19.5 319 -25 185 19.1 320 -25 195 20.8 321 -25 205 23.5 322 -25 215 21.4 323 -25 225 13.5 324 -25 235 15.7 325 -25 245 11.0 326 -25 255 22.0 327 -25 265 19.8 328 -25 275 17.7 329 -25 285 22.0 332 -25 315 20.5 333 -25 325 15.6 334 -25 335 14.0 335 -25 345 9.1 336 -25 355 17.6 337 -35 5 19.0 338 -35 15 11.9 339 -35 25 13.6 340 -35 35 12.9 341 -35 45 14.2 342 -35 55 21.1 343 -35 65 21.3 344 -35 75 22.3 345 -35 85 19.4 346 -35 95 19.0 347 -35 105 15.9 348 -35 115 16.1 349 -35 125 17.9 350 -35 135 19.0 351 -35 145 16.2 352 -35 155 14.9 353 -35 165 15.4 354 -35 175 16.4 355 -35 185 16.5 356 -35 195 17.8 357 -35 205 19.1 358 -35 215 19.1 359 -35 225 17.0 360 -35 235 10.9 364 -35 275 14.4 365 -35 285 9.3 367 -35 305 13.4 368 -35 315 20.7 369 -35 325 14.1 370 -35 335 14.5 371 -35 345 22.6 372 -35 355 17.7 387 -45 145 17.1 388 -45 155 12.6 389 -45 165 15.0 390 -45 175 17.4 391 -45 185 19.6 392 -45 195 17.1 400 -45 275 13.4 401 -45 285 10.0 402 -45 295 12.0 403 -45 305 18.2 404 -45 315 16.1 417 -55 170 22.7 423 -55 290 16.4 424 -55 310 21.1 425 -55 330 29.2 429 -65 50 16.0 430 -65 70 13.4 431 -65 90 12.5 442 -65 310 22.2