Altocumulus Frequency of Occurrence (%) July (1954 - 1997) Night, Ship Observations Only Global Average: 33.8 Zonal Averages 15 zones Lat.N Average 85 34.4 75 39.6 65 41.5 55 35.4 45 34.4 35 34.5 25 33.7 15 39.0 5 44.2 -5 34.2 -15 32.2 -25 32.1 -35 28.7 -45 26.0 -55 28.0 Grid Box Averages 314 filled boxes Box # Lat.N Lon.E Average 1 85 60 40.2 2 85 180 26.2 3 85 300 38.3 4 75 20 40.0 5 75 60 36.1 6 75 100 43.1 7 75 140 35.1 8 75 180 37.5 9 75 220 41.0 10 75 260 49.8 11 75 300 38.5 12 75 340 43.6 13 65 10 45.6 14 65 30 36.5 15 65 50 38.1 20 65 150 32.8 21 65 170 23.6 22 65 190 35.3 23 65 210 41.1 25 65 250 55.9 26 65 270 45.2 27 65 290 43.6 28 65 310 43.9 29 65 330 40.6 30 65 350 43.7 31 55 10 39.9 32 55 30 34.0 37 55 130 26.4 38 55 150 26.6 39 55 170 26.5 40 55 190 34.1 41 55 210 39.7 42 55 230 39.7 44 55 270 37.8 45 55 290 45.0 46 55 310 36.5 47 55 330 35.6 48 55 350 43.4 49 45 5 21.4 50 45 15 20.7 51 45 25 15.5 52 45 35 14.8 62 45 135 31.9 63 45 145 29.0 64 45 155 34.2 65 45 165 30.3 66 45 175 25.8 67 45 185 28.8 68 45 195 37.3 69 45 205 42.8 70 45 215 42.3 71 45 225 41.6 72 45 235 26.6 77 45 285 36.3 78 45 295 37.2 79 45 305 40.5 80 45 315 34.7 81 45 325 35.2 82 45 335 39.5 83 45 345 36.6 84 45 355 36.0 85 35 5 17.8 86 35 15 8.9 87 35 25 4.6 88 35 35 4.0 96 35 115 33.7 97 35 125 38.8 98 35 135 40.4 99 35 145 43.1 100 35 155 41.1 101 35 165 44.0 102 35 175 36.8 103 35 185 41.7 104 35 195 43.9 105 35 205 47.4 106 35 215 44.4 107 35 225 35.7 108 35 235 26.4 109 35 245 21.2 112 35 275 35.8 113 35 285 38.6 114 35 295 37.8 115 35 305 31.8 116 35 315 28.1 117 35 325 30.9 118 35 335 33.9 119 35 345 25.0 120 35 355 19.6 124 25 35 8.4 125 25 45 5.4 126 25 55 17.9 127 25 65 36.5 131 25 105 50.5 132 25 115 34.9 133 25 125 32.6 134 25 135 40.4 135 25 145 38.2 136 25 155 34.7 137 25 165 37.5 138 25 175 34.6 139 25 185 35.9 140 25 195 35.9 141 25 205 35.8 142 25 215 40.3 143 25 225 38.8 144 25 235 37.1 145 25 245 31.5 146 25 255 46.2 147 25 265 35.9 148 25 275 38.4 149 25 285 36.4 150 25 295 30.2 151 25 305 22.7 152 25 315 26.9 153 25 325 27.4 154 25 335 29.3 155 25 345 20.9 160 15 35 29.3 161 15 45 35.4 162 15 55 23.4 163 15 65 34.5 164 15 75 39.6 165 15 85 46.9 166 15 95 49.7 167 15 105 46.0 168 15 115 40.8 169 15 125 41.8 170 15 135 47.9 171 15 145 44.1 172 15 155 38.8 173 15 165 36.9 174 15 175 33.5 175 15 185 33.0 176 15 195 39.8 177 15 205 36.2 178 15 215 40.8 179 15 225 44.2 180 15 235 45.3 181 15 245 40.3 182 15 255 53.0 183 15 265 54.3 184 15 275 44.8 185 15 285 34.4 186 15 295 30.2 187 15 305 27.7 188 15 315 34.9 189 15 325 33.2 190 15 335 34.5 191 15 345 32.0 193 5 5 51.2 197 5 45 25.6 198 5 55 20.9 199 5 65 30.7 200 5 75 39.3 201 5 85 46.4 202 5 95 55.8 203 5 105 49.3 204 5 115 43.8 205 5 125 50.6 206 5 135 60.1 207 5 145 51.6 208 5 155 51.6 209 5 165 38.7 210 5 175 51.0 211 5 185 47.3 212 5 195 44.0 213 5 205 42.4 214 5 215 33.6 215 5 225 33.3 216 5 235 47.3 217 5 245 46.1 218 5 255 44.1 219 5 265 54.3 220 5 275 62.7 221 5 285 54.7 223 5 305 42.7 224 5 315 42.9 225 5 325 32.3 226 5 335 37.5 227 5 345 42.3 228 5 355 42.0 229 -5 5 33.5 230 -5 15 13.3 233 -5 45 26.9 234 -5 55 30.4 235 -5 65 41.6 236 -5 75 42.4 237 -5 85 46.0 238 -5 95 54.0 239 -5 105 34.3 240 -5 115 35.1 241 -5 125 39.1 242 -5 135 40.4 243 -5 145 48.1 244 -5 155 48.6 245 -5 165 40.9 246 -5 175 45.0 247 -5 185 40.0 248 -5 195 33.4 249 -5 205 23.8 250 -5 215 28.2 251 -5 225 21.8 252 -5 235 15.2 253 -5 245 20.7 254 -5 255 36.2 255 -5 265 44.2 256 -5 275 38.1 260 -5 315 38.4 261 -5 325 28.3 262 -5 335 23.5 263 -5 345 21.2 264 -5 355 23.5 265 -15 5 26.3 266 -15 15 39.4 268 -15 35 18.6 269 -15 45 26.5 270 -15 55 30.7 271 -15 65 29.2 272 -15 75 34.6 273 -15 85 39.1 274 -15 95 47.9 275 -15 105 36.0 276 -15 115 22.3 277 -15 125 10.3 278 -15 135 27.5 279 -15 145 29.4 280 -15 155 38.0 281 -15 165 39.8 282 -15 175 47.3 283 -15 185 39.4 284 -15 195 34.2 285 -15 205 28.9 286 -15 215 24.9 287 -15 225 24.3 288 -15 235 27.0 289 -15 245 29.3 290 -15 255 37.4 292 -15 275 32.1 293 -15 285 24.6 297 -15 325 35.3 298 -15 335 25.4 299 -15 345 36.0 300 -15 355 31.2 301 -25 5 24.6 302 -25 15 15.5 304 -25 35 16.7 305 -25 45 27.9 306 -25 55 32.0 307 -25 65 31.5 308 -25 75 26.6 309 -25 85 23.9 310 -25 95 31.4 311 -25 105 34.8 312 -25 115 22.6 316 -25 155 27.8 317 -25 165 34.4 318 -25 175 39.1 319 -25 185 36.8 320 -25 195 31.4 321 -25 205 40.3 322 -25 215 32.0 323 -25 225 32.9 324 -25 235 32.1 325 -25 245 41.1 328 -25 275 25.0 329 -25 285 27.7 332 -25 315 30.7 333 -25 325 37.3 334 -25 335 41.9 335 -25 345 36.9 336 -25 355 39.8 337 -35 5 34.5 338 -35 15 21.6 339 -35 25 18.5 340 -35 35 19.0 341 -35 45 24.8 342 -35 55 35.4 343 -35 65 29.6 344 -35 75 32.6 345 -35 85 25.4 346 -35 95 30.4 347 -35 105 24.1 348 -35 115 29.4 349 -35 125 35.3 350 -35 135 34.0 351 -35 145 30.6 352 -35 155 29.5 353 -35 165 31.8 354 -35 175 25.7 355 -35 185 28.9 356 -35 195 26.7 357 -35 205 30.4 358 -35 215 28.5 364 -35 275 16.9 365 -35 285 22.5 367 -35 305 26.0 368 -35 315 27.3 369 -35 325 35.4 370 -35 335 28.1 371 -35 345 37.4 372 -35 355 39.8 387 -45 145 32.5 388 -45 155 31.4 389 -45 165 30.9 390 -45 175 20.7 391 -45 185 20.7 400 -45 275 18.6 401 -45 285 30.0 402 -45 295 30.1 403 -45 305 25.0 404 -45 315 24.6 423 -55 290 30.8 424 -55 310 29.2 425 -55 330 24.4