Altocumulus Average Cloud Amount (%) May (1954 - 1997) Night, Ship Observations Only Global Average: 16.3 Zonal Averages 16 zones Lat.N Average 85 11.4 75 12.9 65 17.8 55 15.8 45 16.2 35 16.7 25 14.4 15 14.7 5 21.7 -5 15.2 -15 14.6 -25 15.9 -35 15.5 -45 11.5 -55 15.8 -65 30.4 Grid Box Averages 316 filled boxes Box # Lat.N Lon.E Average 1 85 60 19.0 2 85 180 6.9 3 85 300 7.7 4 75 20 20.2 5 75 60 17.8 7 75 140 9.8 8 75 180 5.0 9 75 220 7.8 11 75 300 17.4 12 75 340 18.5 13 65 10 20.7 14 65 30 16.2 15 65 50 14.7 20 65 150 10.1 21 65 170 11.1 22 65 190 14.5 23 65 210 13.5 28 65 310 14.8 29 65 330 20.0 30 65 350 20.2 31 55 10 16.0 32 55 30 16.2 38 55 150 10.8 39 55 170 14.0 40 55 190 16.6 41 55 210 16.5 42 55 230 15.4 46 55 310 15.7 47 55 330 18.4 48 55 350 18.3 49 45 5 15.3 50 45 15 15.0 51 45 25 11.9 52 45 35 7.2 53 45 45 11.8 54 45 55 9.5 62 45 135 11.4 63 45 145 12.1 64 45 155 11.9 65 45 165 14.1 66 45 175 17.7 67 45 185 19.2 68 45 195 18.3 69 45 205 18.1 70 45 215 18.1 71 45 225 15.7 72 45 235 12.0 77 45 285 16.9 78 45 295 15.8 79 45 305 15.7 80 45 315 17.3 81 45 325 17.6 82 45 335 20.0 83 45 345 17.9 84 45 355 17.4 85 35 5 14.4 86 35 15 12.0 87 35 25 8.9 88 35 35 7.4 97 35 125 16.6 98 35 135 17.1 99 35 145 13.9 100 35 155 15.2 101 35 165 20.1 102 35 175 19.1 103 35 185 23.2 104 35 195 22.0 105 35 205 20.3 106 35 215 20.6 107 35 225 17.2 108 35 235 10.4 109 35 245 7.2 112 35 275 12.7 113 35 285 16.1 114 35 295 16.1 115 35 305 16.1 116 35 315 16.7 117 35 325 16.2 118 35 335 17.6 119 35 345 14.8 120 35 355 13.1 124 25 35 4.3 125 25 45 9.4 126 25 55 3.4 127 25 65 3.7 129 25 85 17.8 132 25 115 18.9 133 25 125 19.5 134 25 135 18.6 135 25 145 15.9 136 25 155 13.4 137 25 165 12.7 138 25 175 13.4 139 25 185 12.9 140 25 195 13.1 141 25 205 13.3 142 25 215 17.1 143 25 225 22.4 144 25 235 19.0 145 25 245 12.7 146 25 255 10.3 147 25 265 14.2 148 25 275 12.0 149 25 285 15.6 150 25 295 15.0 151 25 305 14.4 152 25 315 13.9 153 25 325 12.8 154 25 335 11.7 155 25 345 9.3 160 15 35 6.2 161 15 45 8.2 162 15 55 4.3 163 15 65 4.8 164 15 75 11.0 165 15 85 15.6 166 15 95 19.5 167 15 105 18.6 168 15 115 10.1 169 15 125 10.1 170 15 135 9.1 171 15 145 8.0 172 15 155 9.8 173 15 165 12.4 174 15 175 14.4 175 15 185 16.1 176 15 195 16.8 177 15 205 16.2 178 15 215 25.6 179 15 225 30.7 180 15 235 26.0 181 15 245 15.7 182 15 255 13.2 183 15 265 18.9 184 15 275 18.1 185 15 285 16.8 186 15 295 15.2 187 15 305 12.9 188 15 315 16.1 189 15 325 13.4 190 15 335 12.0 191 15 345 11.6 193 5 5 29.1 197 5 45 9.6 198 5 55 10.2 199 5 65 12.7 200 5 75 18.5 201 5 85 23.4 202 5 95 33.9 203 5 105 17.5 204 5 115 18.1 205 5 125 19.0 206 5 135 24.4 207 5 145 22.5 208 5 155 21.6 209 5 165 21.0 210 5 175 24.1 211 5 185 20.5 212 5 195 26.7 213 5 205 22.5 214 5 215 17.1 215 5 225 21.8 216 5 235 13.6 217 5 245 28.3 218 5 255 17.0 219 5 265 25.9 220 5 275 33.3 221 5 285 27.9 223 5 305 19.3 224 5 315 24.1 225 5 325 21.4 226 5 335 22.0 227 5 345 22.1 228 5 355 26.3 229 -5 5 19.7 230 -5 15 13.2 233 -5 45 12.3 234 -5 55 11.8 235 -5 65 12.3 236 -5 75 18.2 237 -5 85 23.4 238 -5 95 23.6 239 -5 105 22.0 240 -5 115 18.7 241 -5 125 16.7 242 -5 135 22.1 243 -5 145 27.6 244 -5 155 22.1 245 -5 165 19.0 246 -5 175 13.8 247 -5 185 11.8 248 -5 195 8.2 249 -5 205 8.7 250 -5 215 13.7 251 -5 225 6.6 252 -5 235 8.3 253 -5 245 7.8 254 -5 255 12.5 255 -5 265 15.4 256 -5 275 24.3 260 -5 315 23.2 261 -5 325 17.2 262 -5 335 11.2 263 -5 345 12.0 264 -5 355 13.3 265 -15 5 11.7 266 -15 15 26.4 268 -15 35 9.3 269 -15 45 9.6 270 -15 55 12.8 271 -15 65 13.5 272 -15 75 12.9 273 -15 85 16.5 274 -15 95 19.9 275 -15 105 17.2 276 -15 115 10.0 277 -15 125 8.1 278 -15 135 16.5 279 -15 145 17.6 280 -15 155 17.2 281 -15 165 17.5 282 -15 175 18.5 283 -15 185 19.9 284 -15 195 20.7 285 -15 205 14.0 286 -15 215 8.8 287 -15 225 9.2 288 -15 235 11.6 289 -15 245 9.4 290 -15 255 13.9 291 -15 265 17.9 292 -15 275 20.1 293 -15 285 21.3 297 -15 325 15.1 298 -15 335 9.0 299 -15 345 12.9 300 -15 355 13.9 301 -25 5 10.9 302 -25 15 9.4 304 -25 35 8.1 305 -25 45 11.7 306 -25 55 17.1 307 -25 65 12.5 308 -25 75 13.5 309 -25 85 17.3 310 -25 95 18.4 311 -25 105 16.2 312 -25 115 11.2 316 -25 155 13.0 317 -25 165 17.4 318 -25 175 17.9 319 -25 185 20.3 320 -25 195 21.6 321 -25 205 22.9 322 -25 215 18.1 323 -25 225 16.4 324 -25 235 17.1 325 -25 245 14.7 326 -25 255 15.6 327 -25 265 11.4 328 -25 275 10.1 329 -25 285 16.3 332 -25 315 20.5 333 -25 325 18.1 334 -25 335 18.9 335 -25 345 17.6 336 -25 355 14.6 337 -35 5 19.5 338 -35 15 11.0 339 -35 25 12.0 340 -35 35 10.3 341 -35 45 15.7 342 -35 55 19.0 343 -35 65 18.3 344 -35 75 14.5 345 -35 85 14.2 346 -35 95 13.5 347 -35 105 15.6 348 -35 115 14.5 349 -35 125 16.4 350 -35 135 18.3 351 -35 145 19.8 352 -35 155 14.8 353 -35 165 13.5 354 -35 175 13.6 355 -35 185 15.7 356 -35 195 13.8 357 -35 205 15.3 358 -35 215 20.2 359 -35 225 16.7 364 -35 275 13.8 365 -35 285 8.6 367 -35 305 14.8 368 -35 315 19.3 369 -35 325 18.8 370 -35 335 13.4 371 -35 345 16.5 372 -35 355 19.3 387 -45 145 20.7 388 -45 155 10.2 389 -45 165 14.2 390 -45 175 10.0 391 -45 185 12.3 397 -45 245 8.5 398 -45 255 7.2 399 -45 265 8.1 400 -45 275 9.0 401 -45 285 11.7 402 -45 295 16.0 403 -45 305 13.6 404 -45 315 10.7 417 -55 170 20.4 423 -55 290 12.4 424 -55 310 16.5 425 -55 330 13.3 442 -65 310 30.4