Altocumulus Average Cloud Amount (%) March (1954 - 1997) Night, Ship Observations Only Global Average: 16.5 Zonal Averages 17 zones Lat.N Average 85 13.4 75 12.0 65 12.6 55 11.1 45 12.3 35 14.6 25 13.4 15 10.8 5 17.4 -5 18.8 -15 16.6 -25 17.9 -35 17.7 -45 20.3 -55 21.7 -65 19.2 -75 15.5 Grid Box Averages 342 filled boxes Box # Lat.N Lon.E Average 1 85 60 18.1 2 85 180 11.8 3 85 300 9.3 4 75 20 15.3 5 75 60 7.8 7 75 140 12.7 8 75 180 8.0 9 75 220 17.3 12 75 340 10.1 13 65 10 18.5 14 65 30 17.3 15 65 50 5.1 21 65 170 4.0 22 65 190 5.6 29 65 330 13.0 30 65 350 15.6 31 55 10 14.5 32 55 30 15.4 38 55 150 6.3 39 55 170 8.6 40 55 190 9.8 41 55 210 11.2 42 55 230 9.6 46 55 310 9.6 47 55 330 16.1 48 55 350 13.9 49 45 5 15.4 50 45 15 11.9 51 45 25 11.9 52 45 35 13.4 62 45 135 6.3 63 45 145 6.0 64 45 155 8.6 65 45 165 10.4 66 45 175 10.4 67 45 185 13.5 68 45 195 12.1 69 45 205 12.8 70 45 215 13.6 71 45 225 13.1 72 45 235 13.6 77 45 285 10.2 78 45 295 11.1 79 45 305 11.4 80 45 315 14.2 81 45 325 15.6 82 45 335 15.7 83 45 345 13.7 84 45 355 14.1 85 35 5 14.8 86 35 15 11.7 87 35 25 11.9 88 35 35 10.0 97 35 125 12.2 98 35 135 12.1 99 35 145 11.4 100 35 155 12.9 101 35 165 14.1 102 35 175 14.5 103 35 185 18.0 104 35 195 16.9 105 35 205 15.5 106 35 215 18.1 107 35 225 13.8 108 35 235 11.0 109 35 245 8.3 112 35 275 15.5 113 35 285 15.8 114 35 295 15.9 115 35 305 16.8 116 35 315 16.9 117 35 325 17.1 118 35 335 15.8 119 35 345 13.6 120 35 355 12.0 124 25 35 6.7 125 25 45 14.8 126 25 55 9.0 127 25 65 5.3 129 25 85 4.3 132 25 115 18.6 133 25 125 14.2 134 25 135 13.1 135 25 145 14.5 136 25 155 12.8 137 25 165 13.8 138 25 175 12.8 139 25 185 13.9 140 25 195 12.5 141 25 205 13.8 142 25 215 17.1 143 25 225 21.1 144 25 235 17.7 145 25 245 11.9 146 25 255 11.7 147 25 265 18.1 148 25 275 13.8 149 25 285 12.3 150 25 295 10.8 151 25 305 10.8 152 25 315 13.6 153 25 325 11.8 154 25 335 10.5 155 25 345 7.1 160 15 35 6.5 161 15 45 6.9 162 15 55 3.8 163 15 65 2.6 164 15 75 3.9 165 15 85 5.3 166 15 95 5.1 167 15 105 8.4 168 15 115 6.8 169 15 125 10.1 170 15 135 9.3 171 15 145 9.6 172 15 155 11.0 173 15 165 8.9 174 15 175 9.4 175 15 185 9.5 176 15 195 13.6 177 15 205 15.1 178 15 215 16.5 179 15 225 26.2 180 15 235 25.9 181 15 245 17.9 182 15 255 7.8 183 15 265 6.7 184 15 275 9.0 185 15 285 7.5 186 15 295 8.1 187 15 305 8.7 188 15 315 12.1 189 15 325 12.2 190 15 335 11.5 191 15 345 7.6 193 5 5 20.7 197 5 45 3.6 198 5 55 6.0 199 5 65 5.4 200 5 75 8.1 201 5 85 14.9 202 5 95 22.7 203 5 105 14.7 204 5 115 15.0 205 5 125 17.9 206 5 135 19.9 207 5 145 19.1 208 5 155 20.5 209 5 165 21.4 210 5 175 20.0 211 5 185 20.3 212 5 195 20.9 213 5 205 25.3 214 5 215 20.3 215 5 225 21.5 216 5 235 18.5 217 5 245 12.6 218 5 255 13.3 219 5 265 15.1 220 5 275 16.8 221 5 285 15.4 223 5 305 13.5 224 5 315 25.5 225 5 325 20.6 226 5 335 18.6 227 5 345 15.8 228 5 355 17.5 229 -5 5 22.6 230 -5 15 19.9 233 -5 45 10.9 234 -5 55 8.3 235 -5 65 12.8 236 -5 75 17.0 237 -5 85 20.7 238 -5 95 26.4 239 -5 105 28.4 240 -5 115 31.3 241 -5 125 23.8 242 -5 135 26.1 243 -5 145 30.4 244 -5 155 24.9 245 -5 165 26.8 246 -5 175 22.4 247 -5 185 21.3 248 -5 195 21.4 249 -5 205 9.2 250 -5 215 9.9 251 -5 225 12.9 252 -5 235 15.0 253 -5 245 18.3 254 -5 255 20.2 255 -5 265 16.9 256 -5 275 29.6 257 -5 285 24.2 260 -5 315 35.9 261 -5 325 20.2 262 -5 335 12.7 263 -5 345 10.6 264 -5 355 11.0 265 -15 5 18.1 266 -15 15 29.0 268 -15 35 10.0 269 -15 45 13.7 270 -15 55 13.3 271 -15 65 13.5 272 -15 75 17.8 273 -15 85 15.7 274 -15 95 17.2 275 -15 105 14.0 276 -15 115 13.2 277 -15 125 18.8 278 -15 135 22.0 279 -15 145 24.0 280 -15 155 18.4 281 -15 165 19.3 282 -15 175 23.9 283 -15 185 25.6 284 -15 195 20.9 285 -15 205 12.5 286 -15 215 12.7 287 -15 225 10.1 288 -15 235 11.8 289 -15 245 17.1 290 -15 255 17.8 291 -15 265 16.3 292 -15 275 20.8 293 -15 285 20.0 297 -15 325 15.1 298 -15 335 12.0 299 -15 345 12.4 300 -15 355 14.6 301 -25 5 16.9 302 -25 15 12.0 304 -25 35 11.0 305 -25 45 13.5 306 -25 55 17.7 307 -25 65 17.7 308 -25 75 19.3 309 -25 85 18.9 310 -25 95 21.0 311 -25 105 16.2 312 -25 115 12.4 316 -25 155 12.9 317 -25 165 16.5 318 -25 175 19.3 319 -25 185 24.4 320 -25 195 27.9 321 -25 205 19.4 322 -25 215 15.4 323 -25 225 14.4 324 -25 235 15.6 325 -25 245 14.9 326 -25 255 17.7 327 -25 265 20.8 328 -25 275 19.8 329 -25 285 25.7 332 -25 315 22.2 333 -25 325 18.6 334 -25 335 13.8 335 -25 345 14.7 336 -25 355 16.8 337 -35 5 18.4 338 -35 15 10.8 339 -35 25 12.7 340 -35 35 13.2 341 -35 45 14.9 342 -35 55 18.8 343 -35 65 21.3 344 -35 75 17.4 345 -35 85 19.6 346 -35 95 23.1 347 -35 105 18.3 348 -35 115 15.1 349 -35 125 20.5 350 -35 135 19.7 351 -35 145 15.8 352 -35 155 15.1 353 -35 165 16.6 354 -35 175 16.2 355 -35 185 21.1 356 -35 195 21.3 357 -35 205 21.6 358 -35 215 20.4 359 -35 225 25.1 360 -35 235 22.4 363 -35 265 14.5 364 -35 275 17.4 365 -35 285 11.8 367 -35 305 10.6 368 -35 315 12.0 369 -35 325 13.8 370 -35 335 15.6 371 -35 345 21.7 372 -35 355 19.6 374 -45 15 25.9 376 -45 35 26.1 377 -45 45 32.2 378 -45 55 14.9 380 -45 75 17.9 381 -45 85 25.9 386 -45 135 19.7 387 -45 145 15.2 388 -45 155 20.4 389 -45 165 13.8 390 -45 175 15.9 391 -45 185 22.9 392 -45 195 22.7 399 -45 265 31.2 400 -45 275 12.5 401 -45 285 13.2 402 -45 295 11.5 403 -45 305 13.3 404 -45 315 21.1 409 -55 10 25.9 410 -55 30 22.6 411 -55 50 21.3 412 -55 70 18.4 413 -55 90 14.0 417 -55 170 26.2 418 -55 190 23.4 422 -55 270 19.4 423 -55 290 19.6 424 -55 310 22.3 425 -55 330 22.0 426 -55 350 24.5 427 -65 10 19.3 428 -65 30 18.7 429 -65 50 21.1 430 -65 70 10.3 431 -65 90 17.3 432 -65 110 18.0 433 -65 130 24.4 434 -65 150 14.6 435 -65 170 16.3 437 -65 210 19.1 441 -65 290 16.2 442 -65 310 25.9 444 -65 350 26.9 449 -75 180 14.3 450 -75 220 11.9 453 -75 340 21.9