Altocumulus Average Cloud Amount (%) March, April, May (1954 - 1997) Day, Ship Observations Only Global Average: 17.1 Zonal Averages 17 zones Lat.N Average 85 11.4 75 12.2 65 15.6 55 14.9 45 15.3 35 16.7 25 13.9 15 12.0 5 19.1 -5 17.3 -15 15.6 -25 17.4 -35 18.6 -45 19.8 -55 22.0 -65 22.3 -75 16.8 Grid Box Averages 392 filled boxes Box # Lat.N Lon.E Average 1 85 60 15.2 2 85 180 8.7 3 85 300 10.0 4 75 20 17.2 5 75 60 12.9 6 75 100 5.1 7 75 140 13.5 8 75 180 8.3 9 75 220 10.8 11 75 300 16.9 12 75 340 12.7 13 65 10 20.3 14 65 30 13.4 15 65 50 13.9 16 65 70 9.0 21 65 170 8.6 22 65 190 9.0 23 65 210 14.6 27 65 290 14.6 29 65 330 17.8 30 65 350 18.2 31 55 10 16.0 32 55 30 16.9 37 55 130 12.4 38 55 150 9.9 39 55 170 12.0 40 55 190 13.4 41 55 210 15.5 42 55 230 15.6 45 55 290 14.6 46 55 310 14.6 47 55 330 18.8 48 55 350 18.6 49 45 5 14.9 50 45 15 14.8 51 45 25 12.0 52 45 35 9.2 53 45 45 12.4 54 45 55 9.8 61 45 125 10.3 62 45 135 9.4 63 45 145 9.6 64 45 155 11.1 65 45 165 12.7 66 45 175 14.2 67 45 185 15.6 68 45 195 16.3 69 45 205 17.2 70 45 215 17.2 71 45 225 17.0 72 45 235 15.5 77 45 285 12.6 78 45 295 13.4 79 45 305 15.3 80 45 315 17.6 81 45 325 19.1 82 45 335 19.3 83 45 345 17.1 84 45 355 16.3 85 35 5 14.5 86 35 15 12.8 87 35 25 11.4 88 35 35 9.8 89 35 45 10.2 90 35 55 9.4 96 35 115 8.4 97 35 125 14.7 98 35 135 15.3 99 35 145 14.2 100 35 155 15.9 101 35 165 16.7 102 35 175 17.4 103 35 185 19.1 104 35 195 19.7 105 35 205 20.6 106 35 215 20.6 107 35 225 17.8 108 35 235 12.6 109 35 245 8.9 112 35 275 13.0 113 35 285 16.1 114 35 295 17.0 115 35 305 17.7 116 35 315 18.5 117 35 325 18.6 118 35 335 18.7 119 35 345 14.2 120 35 355 12.8 124 25 35 5.1 125 25 45 10.0 126 25 55 7.3 127 25 65 3.9 128 25 75 4.3 129 25 85 8.5 130 25 95 8.1 131 25 105 22.4 132 25 115 20.2 133 25 125 18.2 134 25 135 15.6 135 25 145 14.2 136 25 155 14.0 137 25 165 13.4 138 25 175 12.7 139 25 185 13.0 140 25 195 13.3 141 25 205 14.0 142 25 215 17.4 143 25 225 20.1 144 25 235 18.5 145 25 245 12.5 146 25 255 10.2 147 25 265 15.0 148 25 275 12.5 149 25 285 12.8 150 25 295 13.3 151 25 305 13.5 152 25 315 13.7 153 25 325 13.7 154 25 335 11.6 155 25 345 7.5 156 25 355 11.7 160 15 35 5.8 161 15 45 6.1 162 15 55 3.9 163 15 65 4.0 164 15 75 6.6 165 15 85 8.2 166 15 95 9.3 167 15 105 14.8 168 15 115 9.5 169 15 125 9.9 170 15 135 9.2 171 15 145 9.2 172 15 155 10.1 173 15 165 12.0 174 15 175 11.6 175 15 185 12.4 176 15 195 15.4 177 15 205 15.7 178 15 215 19.1 179 15 225 23.5 180 15 235 23.7 181 15 245 15.2 182 15 255 8.7 183 15 265 9.3 184 15 275 11.6 185 15 285 11.6 186 15 295 11.6 187 15 305 12.0 188 15 315 13.3 189 15 325 13.3 190 15 335 10.1 191 15 345 7.5 193 5 5 22.9 197 5 45 7.4 198 5 55 8.2 199 5 65 9.4 200 5 75 14.6 201 5 85 21.6 202 5 95 27.5 203 5 105 17.8 204 5 115 17.4 205 5 125 17.5 206 5 135 18.7 207 5 145 19.5 208 5 155 21.8 209 5 165 25.1 210 5 175 21.6 211 5 185 20.4 212 5 195 19.4 213 5 205 20.9 214 5 215 20.8 215 5 225 18.2 216 5 235 17.9 217 5 245 17.9 218 5 255 15.1 219 5 265 17.3 220 5 275 23.1 221 5 285 23.8 222 5 295 14.0 223 5 305 17.6 224 5 315 22.7 225 5 325 21.7 226 5 335 18.1 227 5 345 19.2 228 5 355 23.0 229 -5 5 18.3 230 -5 15 20.6 232 -5 35 16.2 233 -5 45 12.0 234 -5 55 11.7 235 -5 65 17.1 236 -5 75 19.3 237 -5 85 24.9 238 -5 95 26.3 239 -5 105 27.0 240 -5 115 25.1 241 -5 125 21.1 242 -5 135 25.8 243 -5 145 29.0 244 -5 155 26.2 245 -5 165 24.1 246 -5 175 20.9 247 -5 185 16.8 248 -5 195 15.1 249 -5 205 11.0 250 -5 215 10.2 251 -5 225 9.3 252 -5 235 10.5 253 -5 245 12.4 254 -5 255 13.5 255 -5 265 15.4 256 -5 275 17.1 257 -5 285 24.3 260 -5 315 28.7 261 -5 325 19.7 262 -5 335 14.0 263 -5 345 10.3 264 -5 355 12.7 265 -15 5 12.6 266 -15 15 28.3 268 -15 35 10.3 269 -15 45 14.4 270 -15 55 13.8 271 -15 65 13.8 272 -15 75 16.0 273 -15 85 17.6 274 -15 95 18.7 275 -15 105 14.8 276 -15 115 11.6 277 -15 125 11.8 278 -15 135 20.9 279 -15 145 19.6 280 -15 155 18.6 281 -15 165 20.7 282 -15 175 23.0 283 -15 185 23.2 284 -15 195 20.2 285 -15 205 18.2 286 -15 215 12.4 287 -15 225 10.9 288 -15 235 11.4 289 -15 245 12.6 290 -15 255 14.6 291 -15 265 15.2 292 -15 275 15.5 293 -15 285 19.3 297 -15 325 16.2 298 -15 335 10.0 299 -15 345 10.6 300 -15 355 12.5 301 -25 5 11.2 302 -25 15 11.7 304 -25 35 11.4 305 -25 45 13.3 306 -25 55 16.4 307 -25 65 15.2 308 -25 75 16.7 309 -25 85 15.2 310 -25 95 18.5 311 -25 105 17.5 312 -25 115 12.8 315 -25 145 16.3 316 -25 155 15.0 317 -25 165 16.6 318 -25 175 20.3 319 -25 185 21.3 320 -25 195 24.2 321 -25 205 23.4 322 -25 215 21.6 323 -25 225 20.3 324 -25 235 17.1 325 -25 245 17.2 326 -25 255 17.6 327 -25 265 16.2 328 -25 275 14.6 329 -25 285 20.0 332 -25 315 21.5 333 -25 325 18.5 334 -25 335 17.6 335 -25 345 15.4 336 -25 355 16.4 337 -35 5 18.8 338 -35 15 12.5 339 -35 25 15.0 340 -35 35 14.7 341 -35 45 16.6 342 -35 55 17.9 343 -35 65 18.5 344 -35 75 17.7 345 -35 85 19.3 346 -35 95 21.2 347 -35 105 19.1 348 -35 115 18.0 349 -35 125 20.9 350 -35 135 20.9 351 -35 145 19.0 352 -35 155 17.0 353 -35 165 17.9 354 -35 175 18.2 355 -35 185 18.9 356 -35 195 19.2 357 -35 205 20.9 358 -35 215 22.6 359 -35 225 22.8 360 -35 235 22.8 361 -35 245 21.2 362 -35 255 18.8 363 -35 265 17.5 364 -35 275 13.7 365 -35 285 14.6 366 -35 295 18.1 367 -35 305 14.1 368 -35 315 18.2 369 -35 325 19.0 370 -35 335 19.5 371 -35 345 19.5 372 -35 355 20.5 373 -45 5 20.7 374 -45 15 25.5 375 -45 25 26.2 376 -45 35 23.6 377 -45 45 23.6 378 -45 55 21.3 379 -45 65 19.9 380 -45 75 20.0 381 -45 85 27.7 382 -45 95 25.2 383 -45 105 21.4 384 -45 115 17.5 385 -45 125 19.4 386 -45 135 22.9 387 -45 145 19.6 388 -45 155 20.1 389 -45 165 18.1 390 -45 175 17.6 391 -45 185 19.4 392 -45 195 18.0 393 -45 205 15.6 394 -45 215 17.2 395 -45 225 22.0 396 -45 235 20.8 397 -45 245 11.6 398 -45 255 11.7 399 -45 265 13.8 400 -45 275 12.3 401 -45 285 13.4 402 -45 295 14.6 403 -45 305 17.0 404 -45 315 20.3 405 -45 325 23.4 406 -45 335 17.6 407 -45 345 26.9 408 -45 355 21.7 409 -55 10 25.5 410 -55 30 22.1 411 -55 50 25.3 412 -55 70 22.4 413 -55 90 20.3 414 -55 110 23.9 415 -55 130 24.1 416 -55 150 20.1 417 -55 170 24.9 418 -55 190 22.0 419 -55 210 13.3 420 -55 230 16.1 421 -55 250 19.4 422 -55 270 16.9 423 -55 290 20.0 424 -55 310 28.9 425 -55 330 24.9 426 -55 350 26.3 427 -65 10 24.0 428 -65 30 24.4 429 -65 50 22.8 430 -65 70 16.9 431 -65 90 23.4 432 -65 110 27.5 433 -65 130 19.4 434 -65 150 20.4 435 -65 170 26.6 436 -65 190 17.2 437 -65 210 17.9 438 -65 230 22.1 440 -65 270 21.8 441 -65 290 17.3 442 -65 310 36.6 443 -65 330 17.2 444 -65 350 22.7 449 -75 180 14.4 450 -75 220 16.7 453 -75 340 20.9