Altostratus Amount-When-Present (%) June, July, August (1954 - 1997) , Ship Observations Only Global Average: 58.0 Zonal Averages 15 zones Lat.N Average 85 78.8 75 67.1 65 69.8 55 71.3 45 68.6 35 57.3 25 47.7 15 56.8 5 61.3 -5 53.4 -15 52.1 -25 52.5 -35 59.1 -45 59.0 -55 64.8 Grid Box Averages 324 filled boxes Box # Lat.N Lon.E Average 1 85 60 76.7 2 85 180 84.8 3 85 300 74.5 4 75 20 65.9 5 75 60 58.4 6 75 100 62.1 7 75 140 66.9 8 75 180 81.6 9 75 220 72.4 10 75 260 73.0 11 75 300 62.6 12 75 340 69.8 13 65 10 64.8 14 65 30 55.2 15 65 50 53.3 20 65 150 54.7 21 65 170 66.7 22 65 190 70.7 23 65 210 56.8 25 65 250 66.8 26 65 270 71.2 27 65 290 71.5 28 65 310 73.5 29 65 330 80.2 30 65 350 67.4 31 55 10 70.7 32 55 30 52.0 37 55 130 55.8 38 55 150 62.0 39 55 170 73.9 40 55 190 75.0 41 55 210 68.3 42 55 230 65.2 45 55 290 66.4 46 55 310 73.0 47 55 330 77.7 48 55 350 73.2 49 45 5 45.7 50 45 15 43.9 51 45 25 39.1 52 45 35 41.9 53 45 45 23.5 54 45 55 29.0 62 45 135 63.6 63 45 145 64.5 64 45 155 67.8 65 45 165 72.8 66 45 175 74.2 67 45 185 74.9 68 45 195 72.3 69 45 205 69.3 70 45 215 67.3 71 45 225 65.1 72 45 235 53.6 77 45 285 59.2 78 45 295 62.8 79 45 305 66.2 80 45 315 70.4 81 45 325 70.2 82 45 335 70.9 83 45 345 69.2 84 45 355 62.1 85 35 5 52.0 86 35 15 42.1 87 35 25 36.0 88 35 35 31.8 96 35 115 56.2 97 35 125 63.5 98 35 135 61.2 99 35 145 57.6 100 35 155 59.6 101 35 165 65.8 102 35 175 58.4 103 35 185 59.6 104 35 195 57.1 105 35 205 51.9 106 35 215 54.5 107 35 225 56.1 108 35 235 57.0 109 35 245 59.7 112 35 275 44.6 113 35 285 58.2 114 35 295 61.5 115 35 305 55.8 116 35 315 53.9 117 35 325 49.8 118 35 335 51.5 119 35 345 55.5 120 35 355 49.5 124 25 35 48.3 126 25 55 61.8 127 25 65 63.7 128 25 75 65.9 129 25 85 71.7 132 25 115 57.0 133 25 125 47.4 134 25 135 45.5 135 25 145 43.9 136 25 155 46.9 137 25 165 41.1 138 25 175 41.8 139 25 185 40.8 140 25 195 35.4 141 25 205 34.8 142 25 215 47.2 143 25 225 53.9 144 25 235 62.1 145 25 245 46.7 146 25 255 45.6 147 25 265 44.3 148 25 275 44.3 149 25 285 47.0 150 25 295 48.0 151 25 305 45.9 152 25 315 38.7 153 25 325 40.1 154 25 335 54.7 155 25 345 61.4 160 15 35 62.3 161 15 45 66.7 162 15 55 60.0 163 15 65 65.6 164 15 75 71.6 165 15 85 66.3 166 15 95 72.8 167 15 105 64.9 168 15 115 58.9 169 15 125 52.9 170 15 135 58.7 171 15 145 48.8 172 15 155 51.3 173 15 165 52.6 174 15 175 45.8 175 15 185 42.0 176 15 195 44.7 177 15 205 44.6 178 15 215 48.3 179 15 225 50.7 180 15 235 61.3 181 15 245 51.4 182 15 255 57.8 183 15 265 63.5 184 15 275 58.1 185 15 285 52.5 186 15 295 48.3 187 15 305 51.7 188 15 315 53.3 189 15 325 55.0 190 15 335 64.0 191 15 345 69.6 193 5 5 71.7 197 5 45 41.9 198 5 55 48.4 199 5 65 62.6 200 5 75 68.3 201 5 85 67.2 202 5 95 74.7 203 5 105 66.0 204 5 115 64.6 205 5 125 61.5 206 5 135 64.4 207 5 145 53.9 208 5 155 54.4 209 5 165 55.2 210 5 175 53.1 211 5 185 50.6 212 5 195 56.3 213 5 205 58.8 214 5 215 56.8 215 5 225 48.4 216 5 235 46.4 217 5 245 66.7 218 5 255 67.0 219 5 265 67.1 220 5 275 72.4 221 5 285 78.5 223 5 305 53.1 224 5 315 46.8 225 5 325 47.0 226 5 335 62.1 227 5 345 72.4 228 5 355 68.3 229 -5 5 58.7 230 -5 15 64.0 233 -5 45 43.2 234 -5 55 47.7 235 -5 65 64.8 236 -5 75 61.7 237 -5 85 72.9 238 -5 95 68.3 239 -5 105 50.5 240 -5 115 42.7 241 -5 125 43.6 242 -5 135 52.9 243 -5 145 59.3 244 -5 155 55.3 245 -5 165 56.2 246 -5 175 47.2 247 -5 185 56.3 248 -5 195 36.2 249 -5 205 31.6 250 -5 215 32.4 252 -5 235 26.1 253 -5 245 33.7 254 -5 255 47.9 255 -5 265 51.1 256 -5 275 68.3 257 -5 285 81.6 260 -5 315 28.9 261 -5 325 42.2 262 -5 335 34.8 263 -5 345 40.0 264 -5 355 50.9 265 -15 5 63.1 266 -15 15 72.8 268 -15 35 30.3 269 -15 45 33.1 270 -15 55 45.7 271 -15 65 44.6 272 -15 75 48.8 273 -15 85 57.0 274 -15 95 57.4 275 -15 105 46.5 276 -15 115 29.6 277 -15 125 30.1 278 -15 135 38.9 279 -15 145 49.0 280 -15 155 47.6 281 -15 165 58.2 282 -15 175 53.3 283 -15 185 50.0 284 -15 195 52.8 285 -15 205 50.4 286 -15 215 45.0 287 -15 225 35.4 288 -15 235 51.8 289 -15 245 47.1 290 -15 255 47.9 291 -15 265 48.4 292 -15 275 67.8 293 -15 285 74.7 297 -15 325 42.2 298 -15 335 33.4 299 -15 345 47.1 300 -15 355 59.1 301 -25 5 52.9 302 -25 15 54.3 304 -25 35 45.1 305 -25 45 42.2 306 -25 55 47.9 307 -25 65 44.1 308 -25 75 51.0 309 -25 85 47.6 310 -25 95 53.5 311 -25 105 56.2 312 -25 115 46.0 316 -25 155 50.8 317 -25 165 51.7 318 -25 175 57.0 319 -25 185 61.2 320 -25 195 67.2 321 -25 205 68.2 322 -25 215 63.4 323 -25 225 59.1 324 -25 235 60.8 325 -25 245 46.8 326 -25 255 53.9 328 -25 275 37.5 329 -25 285 60.4 332 -25 315 51.0 333 -25 325 41.0 334 -25 335 46.3 335 -25 345 36.6 336 -25 355 53.9 337 -35 5 51.8 338 -35 15 54.5 339 -35 25 55.0 340 -35 35 49.7 341 -35 45 48.8 342 -35 55 57.7 343 -35 65 52.1 344 -35 75 51.7 345 -35 85 62.1 346 -35 95 54.5 347 -35 105 58.5 348 -35 115 56.6 349 -35 125 59.3 350 -35 135 62.4 351 -35 145 55.3 352 -35 155 58.2 353 -35 165 60.1 354 -35 175 62.8 355 -35 185 63.5 356 -35 195 62.3 357 -35 205 73.0 358 -35 215 72.7 359 -35 225 73.4 364 -35 275 46.3 365 -35 285 54.4 367 -35 305 56.7 368 -35 315 62.4 369 -35 325 61.0 370 -35 335 60.3 371 -35 345 64.1 372 -35 355 55.9 387 -45 145 49.4 388 -45 155 69.4 389 -45 165 65.7 390 -45 175 59.8 391 -45 185 50.4 392 -45 195 58.3 393 -45 205 67.9 397 -45 245 48.6 398 -45 255 47.9 400 -45 275 56.5 401 -45 285 59.7 402 -45 295 58.2 403 -45 305 57.9 404 -45 315 62.7 405 -45 325 63.6 417 -55 170 83.7 423 -55 290 66.1 424 -55 310 66.9 425 -55 330 52.0