Altocumulus Average Cloud Amount (%) March (1954 - 1997) Day, Ship Observations Only Global Average: 17.3 Zonal Averages 17 zones Lat.N Average 85 12.9 75 12.9 65 14.9 55 13.6 45 13.8 35 16.4 25 13.8 15 10.6 5 17.2 -5 19.4 -15 16.6 -25 17.4 -35 18.8 -45 21.8 -55 23.7 -65 22.1 -75 16.8 Grid Box Averages 382 filled boxes Box # Lat.N Lon.E Average 1 85 60 17.2 2 85 180 10.9 3 85 300 9.8 4 75 20 16.2 5 75 60 10.2 6 75 100 3.2 7 75 140 21.1 8 75 180 9.3 9 75 220 13.7 12 75 340 12.0 13 65 10 20.6 14 65 30 11.8 15 65 50 12.9 21 65 170 6.3 22 65 190 6.7 23 65 210 8.3 29 65 330 16.6 30 65 350 17.8 31 55 10 16.6 32 55 30 16.0 38 55 150 8.9 39 55 170 10.1 40 55 190 11.3 41 55 210 13.9 42 55 230 14.4 46 55 310 12.4 47 55 330 17.7 48 55 350 18.5 49 45 5 14.9 50 45 15 14.8 51 45 25 12.1 52 45 35 9.8 53 45 45 13.4 54 45 55 11.0 62 45 135 7.3 63 45 145 7.7 64 45 155 8.9 65 45 165 10.7 66 45 175 11.3 67 45 185 12.7 68 45 195 13.3 69 45 205 14.6 70 45 215 15.2 71 45 225 16.1 72 45 235 15.7 77 45 285 11.9 78 45 295 12.1 79 45 305 13.8 80 45 315 16.4 81 45 325 17.8 82 45 335 18.5 83 45 345 16.9 84 45 355 16.7 85 35 5 15.1 86 35 15 14.1 87 35 25 13.9 88 35 35 11.9 89 35 45 12.0 90 35 55 16.5 96 35 115 3.1 97 35 125 13.5 98 35 135 13.9 99 35 145 13.1 100 35 155 14.7 101 35 165 15.3 102 35 175 15.4 103 35 185 17.3 104 35 195 18.1 105 35 205 18.9 106 35 215 19.7 107 35 225 17.4 108 35 235 13.3 109 35 245 9.8 112 35 275 14.5 113 35 285 17.1 114 35 295 18.1 115 35 305 18.6 116 35 315 18.9 117 35 325 18.8 118 35 335 18.6 119 35 345 15.1 120 35 355 13.4 124 25 35 6.1 125 25 45 16.2 126 25 55 10.0 127 25 65 4.5 128 25 75 3.6 129 25 85 6.2 130 25 95 3.8 131 25 105 25.8 132 25 115 18.4 133 25 125 15.7 134 25 135 13.8 135 25 145 13.5 136 25 155 14.4 137 25 165 13.7 138 25 175 13.0 139 25 185 12.7 140 25 195 12.7 141 25 205 14.8 142 25 215 17.5 143 25 225 18.8 144 25 235 19.6 145 25 245 13.1 146 25 255 11.8 147 25 265 18.8 148 25 275 13.6 149 25 285 12.8 150 25 295 12.0 151 25 305 12.3 152 25 315 13.6 153 25 325 13.7 154 25 335 11.2 155 25 345 7.4 160 15 35 8.0 161 15 45 6.7 162 15 55 3.4 163 15 65 2.8 164 15 75 3.5 165 15 85 4.3 166 15 95 5.0 167 15 105 11.1 168 15 115 8.6 169 15 125 10.1 170 15 135 9.7 171 15 145 9.8 172 15 155 9.7 173 15 165 10.0 174 15 175 9.1 175 15 185 9.9 176 15 195 14.2 177 15 205 13.6 178 15 215 17.9 179 15 225 22.1 180 15 235 21.7 181 15 245 15.3 182 15 255 7.7 183 15 265 5.1 184 15 275 7.7 185 15 285 8.5 186 15 295 9.1 187 15 305 10.6 188 15 315 12.6 189 15 325 13.1 190 15 335 9.6 191 15 345 7.1 193 5 5 19.8 197 5 45 4.3 198 5 55 5.0 199 5 65 5.5 200 5 75 8.9 201 5 85 18.1 202 5 95 23.3 203 5 105 16.9 204 5 115 16.6 205 5 125 18.1 206 5 135 21.1 207 5 145 19.3 208 5 155 22.9 209 5 165 23.7 210 5 175 19.8 211 5 185 19.3 212 5 195 17.5 213 5 205 21.6 214 5 215 21.3 215 5 225 16.5 216 5 235 19.6 217 5 245 15.8 218 5 255 9.8 219 5 265 13.7 220 5 275 14.8 221 5 285 17.1 223 5 305 16.8 224 5 315 23.3 225 5 325 22.0 226 5 335 16.3 227 5 345 14.9 228 5 355 18.9 229 -5 5 20.1 230 -5 15 22.7 232 -5 35 14.4 233 -5 45 10.8 234 -5 55 12.0 235 -5 65 17.4 236 -5 75 19.5 237 -5 85 25.5 238 -5 95 28.0 239 -5 105 31.5 240 -5 115 30.4 241 -5 125 26.0 242 -5 135 30.3 243 -5 145 33.6 244 -5 155 28.3 245 -5 165 29.4 246 -5 175 25.4 247 -5 185 18.1 248 -5 195 17.1 249 -5 205 13.7 250 -5 215 12.4 251 -5 225 11.2 252 -5 235 12.8 253 -5 245 17.0 254 -5 255 17.1 255 -5 265 17.9 256 -5 275 18.6 257 -5 285 27.0 260 -5 315 30.1 261 -5 325 20.4 262 -5 335 15.2 263 -5 345 9.8 264 -5 355 11.4 265 -15 5 15.1 266 -15 15 28.8 268 -15 35 13.4 269 -15 45 19.9 270 -15 55 14.5 271 -15 65 14.4 272 -15 75 16.4 273 -15 85 16.1 274 -15 95 18.7 275 -15 105 13.2 276 -15 115 11.7 277 -15 125 18.4 278 -15 135 27.1 279 -15 145 23.0 280 -15 155 20.0 281 -15 165 22.3 282 -15 175 25.7 283 -15 185 26.1 284 -15 195 20.0 285 -15 205 18.6 286 -15 215 14.3 287 -15 225 11.1 288 -15 235 12.7 289 -15 245 14.0 290 -15 255 16.3 291 -15 265 16.0 292 -15 275 13.5 293 -15 285 20.6 297 -15 325 16.5 298 -15 335 10.0 299 -15 345 10.4 300 -15 355 13.0 301 -25 5 12.5 302 -25 15 12.5 304 -25 35 13.4 305 -25 45 14.3 306 -25 55 17.6 307 -25 65 14.7 308 -25 75 18.4 309 -25 85 14.4 310 -25 95 19.5 311 -25 105 16.4 312 -25 115 11.0 315 -25 145 18.1 316 -25 155 14.8 317 -25 165 15.9 318 -25 175 20.6 319 -25 185 23.0 320 -25 195 24.8 321 -25 205 21.5 322 -25 215 21.5 323 -25 225 21.0 324 -25 235 16.5 325 -25 245 17.6 326 -25 255 13.5 327 -25 265 14.1 328 -25 275 14.9 329 -25 285 21.3 332 -25 315 22.4 333 -25 325 18.6 334 -25 335 17.3 335 -25 345 14.0 336 -25 355 16.5 337 -35 5 17.6 338 -35 15 10.5 339 -35 25 14.8 340 -35 35 15.9 341 -35 45 18.7 342 -35 55 19.0 343 -35 65 18.7 344 -35 75 19.2 345 -35 85 20.3 346 -35 95 24.3 347 -35 105 20.9 348 -35 115 16.1 349 -35 125 21.7 350 -35 135 20.8 351 -35 145 17.7 352 -35 155 17.2 353 -35 165 18.4 354 -35 175 19.4 355 -35 185 21.4 356 -35 195 21.2 357 -35 205 21.6 358 -35 215 22.1 359 -35 225 22.2 360 -35 235 22.9 361 -35 245 20.8 362 -35 255 17.5 363 -35 265 16.4 364 -35 275 14.1 365 -35 285 13.4 367 -35 305 13.0 368 -35 315 17.7 369 -35 325 18.1 370 -35 335 20.2 371 -35 345 18.2 372 -35 355 19.6 373 -45 5 21.2 374 -45 15 25.2 375 -45 25 24.4 376 -45 35 27.0 377 -45 45 23.8 378 -45 55 22.5 379 -45 65 18.1 380 -45 75 24.6 381 -45 85 28.2 382 -45 95 27.1 383 -45 105 24.9 384 -45 115 16.4 385 -45 125 20.0 386 -45 135 22.1 387 -45 145 20.6 388 -45 155 21.1 389 -45 165 18.0 390 -45 175 18.6 391 -45 185 20.7 392 -45 195 19.6 393 -45 205 19.0 394 -45 215 19.9 395 -45 225 22.1 396 -45 235 26.5 398 -45 255 34.3 399 -45 265 23.7 400 -45 275 13.8 401 -45 285 13.3 402 -45 295 13.6 403 -45 305 16.5 404 -45 315 18.1 405 -45 325 22.3 406 -45 335 17.9 407 -45 345 28.0 408 -45 355 22.8 409 -55 10 26.6 410 -55 30 23.8 411 -55 50 28.6 412 -55 70 21.9 413 -55 90 18.1 414 -55 110 25.5 415 -55 130 26.8 416 -55 150 20.9 417 -55 170 24.3 418 -55 190 20.6 419 -55 210 19.8 420 -55 230 15.7 421 -55 250 23.2 422 -55 270 19.0 423 -55 290 20.9 424 -55 310 29.0 425 -55 330 28.9 426 -55 350 32.0 427 -65 10 22.7 428 -65 30 24.4 429 -65 50 21.9 430 -65 70 16.3 431 -65 90 22.2 432 -65 110 26.9 433 -65 130 17.7 434 -65 150 17.3 435 -65 170 24.9 436 -65 190 14.6 437 -65 210 18.4 438 -65 230 22.8 440 -65 270 25.0 441 -65 290 18.4 442 -65 310 33.0 443 -65 330 23.3 444 -65 350 23.9 449 -75 180 14.1 450 -75 220 17.0 453 -75 340 20.9