Altocumulus Frequency of Occurrence (%) December, January, February (1954 - 1997) , Ship Observations Only Global Average: 36.9 Zonal Averages 17 zones Lat.N Average 85 23.2 75 23.3 65 25.4 55 26.4 45 29.7 35 34.7 25 33.8 15 31.2 5 42.0 -5 40.9 -15 41.6 -25 41.3 -35 38.4 -45 37.6 -55 39.9 -65 35.5 -75 33.0 Grid Box Averages 394 filled boxes Box # Lat.N Lon.E Average 1 85 60 27.6 2 85 180 17.2 3 85 300 25.8 4 75 20 27.9 5 75 60 18.9 6 75 100 6.2 7 75 140 21.2 8 75 180 23.7 9 75 220 25.1 11 75 300 26.4 12 75 340 31.7 13 65 10 35.4 14 65 30 26.9 15 65 50 22.4 21 65 170 10.3 22 65 190 8.0 23 65 210 17.9 27 65 290 23.7 29 65 330 27.4 30 65 350 33.4 31 55 10 27.7 32 55 30 27.8 37 55 130 23.9 38 55 150 17.5 39 55 170 26.2 40 55 190 26.5 41 55 210 28.4 42 55 230 29.5 45 55 290 34.7 46 55 310 20.3 47 55 330 30.6 48 55 350 31.7 49 45 5 33.8 50 45 15 30.2 51 45 25 23.7 52 45 35 21.0 53 45 45 23.2 54 45 55 23.1 61 45 125 23.7 62 45 135 15.3 63 45 145 20.6 64 45 155 26.5 65 45 165 30.8 66 45 175 31.6 67 45 185 31.1 68 45 195 32.8 69 45 205 32.6 70 45 215 35.1 71 45 225 32.8 72 45 235 31.9 77 45 285 19.9 78 45 295 22.0 79 45 305 25.1 80 45 315 27.4 81 45 325 32.4 82 45 335 34.3 83 45 345 32.0 84 45 355 31.4 85 35 5 33.8 86 35 15 32.1 87 35 25 32.2 88 35 35 32.0 89 35 45 34.6 90 35 55 27.5 96 35 115 11.8 97 35 125 26.3 98 35 135 28.1 99 35 145 28.3 100 35 155 36.8 101 35 165 34.6 102 35 175 35.3 103 35 185 36.0 104 35 195 35.8 105 35 205 37.6 106 35 215 40.0 107 35 225 35.6 108 35 235 30.0 109 35 245 22.2 112 35 275 33.0 113 35 285 33.5 114 35 295 36.2 115 35 305 38.0 116 35 315 38.3 117 35 325 38.6 118 35 335 39.5 119 35 345 33.4 120 35 355 31.4 124 25 35 15.9 125 25 45 26.7 126 25 55 19.0 127 25 65 13.2 128 25 75 7.4 129 25 85 16.4 130 25 95 15.9 131 25 105 38.3 132 25 115 32.9 133 25 125 35.6 134 25 135 38.4 135 25 145 40.0 136 25 155 36.2 137 25 165 35.0 138 25 175 34.0 139 25 185 33.8 140 25 195 32.8 141 25 205 33.4 142 25 215 38.7 143 25 225 42.4 144 25 235 41.3 145 25 245 31.1 146 25 255 32.5 147 25 265 37.4 148 25 275 36.4 149 25 285 33.5 150 25 295 31.3 151 25 305 31.4 152 25 315 33.3 153 25 325 33.2 154 25 335 27.0 155 25 345 20.6 156 25 355 22.7 160 15 35 20.3 161 15 45 15.6 162 15 55 15.9 163 15 65 15.4 164 15 75 14.6 165 15 85 21.8 166 15 95 22.2 167 15 105 28.7 168 15 115 33.3 169 15 125 36.7 170 15 135 39.4 171 15 145 38.1 172 15 155 29.2 173 15 165 24.4 174 15 175 27.1 175 15 185 31.8 176 15 195 33.5 177 15 205 34.6 178 15 215 41.1 179 15 225 45.0 180 15 235 46.4 181 15 245 41.9 182 15 255 29.3 183 15 265 22.2 184 15 275 33.8 185 15 285 28.0 186 15 295 29.3 187 15 305 30.2 188 15 315 33.1 189 15 325 33.6 190 15 335 28.1 191 15 345 22.0 193 5 5 33.4 197 5 45 20.7 198 5 55 25.6 199 5 65 26.3 200 5 75 30.3 201 5 85 43.0 202 5 95 49.2 203 5 105 43.8 204 5 115 46.2 205 5 125 50.6 206 5 135 55.3 207 5 145 51.6 208 5 155 50.4 209 5 165 44.8 210 5 175 48.7 211 5 185 45.4 212 5 195 40.9 213 5 205 40.4 214 5 215 40.7 215 5 225 45.8 216 5 235 47.7 217 5 245 45.5 218 5 255 39.5 219 5 265 39.5 220 5 275 43.4 221 5 285 42.0 222 5 295 46.3 223 5 305 40.5 224 5 315 46.7 225 5 325 44.7 226 5 335 38.8 227 5 345 27.4 228 5 355 31.5 229 -5 5 43.2 230 -5 15 40.8 232 -5 35 30.8 233 -5 45 29.8 234 -5 55 39.1 235 -5 65 45.8 236 -5 75 50.5 237 -5 85 52.3 238 -5 95 54.5 239 -5 105 57.3 240 -5 115 57.1 241 -5 125 53.9 242 -5 135 51.8 243 -5 145 56.7 244 -5 155 54.4 245 -5 165 50.3 246 -5 175 50.0 247 -5 185 43.9 248 -5 195 37.8 249 -5 205 31.8 250 -5 215 28.4 251 -5 225 23.1 252 -5 235 24.1 253 -5 245 30.1 254 -5 255 36.8 255 -5 265 39.4 256 -5 275 48.8 257 -5 285 40.7 260 -5 315 45.2 261 -5 325 34.7 262 -5 335 28.3 263 -5 345 28.1 264 -5 355 29.4 265 -15 5 39.5 266 -15 15 34.8 268 -15 35 38.0 269 -15 45 43.1 270 -15 55 39.7 271 -15 65 40.2 272 -15 75 43.3 273 -15 85 44.3 274 -15 95 48.2 275 -15 105 40.0 276 -15 115 34.7 277 -15 125 38.2 278 -15 135 46.3 279 -15 145 46.2 280 -15 155 42.6 281 -15 165 43.6 282 -15 175 49.4 283 -15 185 51.5 284 -15 195 51.4 285 -15 205 45.8 286 -15 215 38.6 287 -15 225 35.8 288 -15 235 36.6 289 -15 245 39.7 290 -15 255 42.9 291 -15 265 46.2 292 -15 275 41.1 293 -15 285 42.1 297 -15 325 38.9 298 -15 335 30.6 299 -15 345 35.3 300 -15 355 37.9 301 -25 5 32.9 302 -25 15 27.4 304 -25 35 33.1 305 -25 45 37.5 306 -25 55 41.4 307 -25 65 41.2 308 -25 75 42.0 309 -25 85 45.0 310 -25 95 47.6 311 -25 105 39.9 312 -25 115 29.4 315 -25 145 33.0 316 -25 155 37.1 317 -25 165 43.5 318 -25 175 47.2 319 -25 185 44.5 320 -25 195 46.9 321 -25 205 44.8 322 -25 215 41.3 323 -25 225 37.8 324 -25 235 41.7 325 -25 245 39.1 326 -25 255 45.2 327 -25 265 50.2 328 -25 275 38.1 329 -25 285 37.2 332 -25 315 47.6 333 -25 325 43.3 334 -25 335 40.4 335 -25 345 39.6 336 -25 355 40.4 337 -35 5 39.9 338 -35 15 27.6 339 -35 25 35.8 340 -35 35 37.8 341 -35 45 39.1 342 -35 55 35.7 343 -35 65 39.4 344 -35 75 41.3 345 -35 85 42.1 346 -35 95 45.4 347 -35 105 41.0 348 -35 115 32.8 349 -35 125 40.5 350 -35 135 39.7 351 -35 145 36.3 352 -35 155 37.7 353 -35 165 41.4 354 -35 175 43.0 355 -35 185 45.0 356 -35 195 44.2 357 -35 205 45.0 358 -35 215 41.3 359 -35 225 38.0 360 -35 235 40.9 361 -35 245 37.4 362 -35 255 41.3 363 -35 265 27.6 364 -35 275 26.8 365 -35 285 23.2 366 -35 295 32.9 367 -35 305 32.8 368 -35 315 34.4 369 -35 325 36.7 370 -35 335 38.8 371 -35 345 41.9 372 -35 355 43.3 373 -45 5 40.7 374 -45 15 38.0 375 -45 25 40.3 376 -45 35 41.3 377 -45 45 33.3 378 -45 55 35.5 379 -45 65 40.2 380 -45 75 39.0 381 -45 85 37.6 382 -45 95 37.6 383 -45 105 41.8 384 -45 115 39.7 385 -45 125 41.5 386 -45 135 41.5 387 -45 145 42.8 388 -45 155 41.5 389 -45 165 38.6 390 -45 175 40.5 391 -45 185 39.8 392 -45 195 42.2 393 -45 205 36.9 394 -45 215 36.4 395 -45 225 38.7 396 -45 235 36.8 397 -45 245 36.9 398 -45 255 35.7 399 -45 265 28.3 400 -45 275 25.3 401 -45 285 31.5 402 -45 295 30.5 403 -45 305 35.8 404 -45 315 37.3 405 -45 325 35.7 406 -45 335 33.9 407 -45 345 37.8 408 -45 355 38.7 409 -55 10 41.3 410 -55 30 37.7 411 -55 50 42.8 412 -55 70 39.3 413 -55 90 40.4 414 -55 110 39.4 415 -55 130 37.2 416 -55 150 32.5 417 -55 170 37.0 418 -55 190 45.0 419 -55 210 43.0 420 -55 230 36.1 421 -55 250 41.8 422 -55 270 38.4 423 -55 290 43.0 424 -55 310 41.8 425 -55 330 39.3 426 -55 350 43.8 427 -65 10 36.7 428 -65 30 53.7 429 -65 50 39.6 430 -65 70 31.0 431 -65 90 34.8 432 -65 110 28.0 433 -65 130 29.3 434 -65 150 32.0 435 -65 170 31.4 436 -65 190 35.2 437 -65 210 33.4 438 -65 230 26.0 439 -65 250 33.2 440 -65 270 38.1 441 -65 290 38.4 442 -65 310 46.6 443 -65 330 32.6 444 -65 350 34.0 449 -75 180 35.9 450 -75 220 27.4 451 -75 260 30.3 452 -75 300 37.7 453 -75 340 33.3