Altostratus Amount-When-Present (%) September, October, November (1954 - 1997) Night, Ship Observations Only Global Average: 61.7 Zonal Averages 16 zones Lat.N Average 85 81.5 75 67.7 65 68.5 55 66.0 45 62.4 35 59.2 25 48.6 15 53.1 5 61.6 -5 62.8 -15 61.0 -25 60.0 -35 64.2 -45 60.9 -55 63.4 -65 85.6 Grid Box Averages 255 filled boxes Box # Lat.N Lon.E Average 1 85 60 75.8 2 85 180 87.9 4 75 20 66.7 5 75 60 57.8 6 75 100 54.9 8 75 180 83.6 9 75 220 70.1 10 75 260 73.5 11 75 300 72.3 12 75 340 66.2 13 65 10 65.7 14 65 30 58.1 15 65 50 56.4 21 65 170 64.2 22 65 190 66.9 26 65 270 78.7 27 65 290 74.5 28 65 310 70.2 29 65 330 76.7 30 65 350 64.1 31 55 10 70.2 32 55 30 59.1 38 55 150 60.9 39 55 170 57.3 40 55 190 60.1 41 55 210 61.2 42 55 230 60.0 46 55 310 76.6 47 55 330 76.9 48 55 350 71.6 49 45 5 51.2 50 45 15 53.5 52 45 35 54.6 62 45 135 53.7 63 45 145 49.6 64 45 155 55.7 65 45 165 54.4 66 45 175 58.3 67 45 185 61.2 68 45 195 63.4 69 45 205 58.4 70 45 215 56.5 71 45 225 63.7 72 45 235 62.5 77 45 285 70.1 78 45 295 69.2 79 45 305 73.4 80 45 315 76.8 81 45 325 71.3 82 45 335 69.3 83 45 345 69.0 84 45 355 63.4 85 35 5 51.2 86 35 15 53.1 87 35 25 51.4 88 35 35 39.9 97 35 125 66.2 98 35 135 64.0 99 35 145 58.5 100 35 155 59.1 101 35 165 64.0 102 35 175 54.5 103 35 185 58.9 104 35 195 59.5 105 35 205 57.7 106 35 215 56.4 107 35 225 58.6 108 35 235 57.1 109 35 245 56.4 112 35 275 50.9 113 35 285 63.1 114 35 295 64.6 115 35 305 61.7 116 35 315 63.6 117 35 325 60.8 118 35 335 56.5 119 35 345 54.5 120 35 355 47.4 124 25 35 40.7 126 25 55 41.4 127 25 65 38.2 132 25 115 61.3 133 25 125 50.2 134 25 135 45.4 135 25 145 44.0 136 25 155 47.0 137 25 165 44.7 138 25 175 44.5 139 25 185 45.0 140 25 195 44.7 141 25 205 50.0 142 25 215 48.4 143 25 225 58.2 144 25 235 55.5 145 25 245 46.9 146 25 255 42.8 147 25 265 48.1 148 25 275 44.7 149 25 285 49.5 150 25 295 53.0 151 25 305 52.4 152 25 315 51.2 153 25 325 45.8 154 25 335 45.5 155 25 345 53.2 160 15 35 53.3 161 15 45 44.3 162 15 55 39.8 163 15 65 38.6 164 15 75 52.5 165 15 85 48.9 166 15 95 58.2 167 15 105 74.8 168 15 115 55.4 169 15 125 51.0 170 15 135 48.8 171 15 145 47.3 172 15 155 49.4 173 15 165 56.8 174 15 175 50.0 175 15 185 50.2 176 15 195 53.0 177 15 205 49.3 178 15 215 48.7 179 15 225 53.9 180 15 235 66.6 181 15 245 59.2 182 15 255 53.5 183 15 265 56.0 184 15 275 56.0 185 15 285 53.8 186 15 295 44.4 187 15 305 48.1 188 15 315 54.8 189 15 325 60.2 190 15 335 59.6 191 15 345 61.3 193 5 5 65.3 198 5 55 37.6 199 5 65 53.4 200 5 75 60.9 201 5 85 64.5 202 5 95 75.3 203 5 105 66.3 204 5 115 65.9 205 5 125 59.4 206 5 135 59.0 207 5 145 54.3 208 5 155 56.2 218 5 255 63.6 219 5 265 69.0 220 5 275 69.9 221 5 285 71.8 223 5 305 46.0 224 5 315 41.6 225 5 325 61.6 226 5 335 64.3 227 5 345 62.5 228 5 355 61.5 229 -5 5 69.9 230 -5 15 56.0 233 -5 45 41.3 235 -5 65 64.6 236 -5 75 67.7 237 -5 85 69.4 238 -5 95 67.6 239 -5 105 67.0 240 -5 115 57.2 241 -5 125 42.9 242 -5 135 53.7 243 -5 145 52.2 244 -5 155 55.5 245 -5 165 56.3 254 -5 255 53.6 255 -5 265 70.8 256 -5 275 81.2 261 -5 325 33.3 262 -5 335 36.8 263 -5 345 54.9 264 -5 355 69.2 265 -15 5 79.8 266 -15 15 54.8 269 -15 45 28.2 270 -15 55 45.2 271 -15 65 51.7 272 -15 75 65.4 273 -15 85 59.1 274 -15 95 54.0 275 -15 105 31.2 277 -15 125 41.6 279 -15 145 45.1 280 -15 155 43.1 281 -15 165 54.9 282 -15 175 62.2 283 -15 185 58.1 285 -15 205 55.1 286 -15 215 53.8 290 -15 255 55.1 292 -15 275 74.6 293 -15 285 67.8 297 -15 325 48.5 299 -15 345 61.3 300 -15 355 81.2 301 -25 5 65.3 302 -25 15 60.1 304 -25 35 64.1 305 -25 45 61.6 306 -25 55 49.2 310 -25 95 52.2 311 -25 105 52.6 312 -25 115 39.9 316 -25 155 47.5 317 -25 165 51.9 318 -25 175 61.6 319 -25 185 57.3 320 -25 195 76.5 322 -25 215 70.7 323 -25 225 67.6 329 -25 285 58.2 332 -25 315 61.6 333 -25 325 59.1 336 -25 355 56.9 337 -35 5 65.3 338 -35 15 51.2 339 -35 25 63.5 340 -35 35 66.5 344 -35 75 72.8 345 -35 85 68.3 346 -35 95 65.8 348 -35 115 57.7 349 -35 125 66.8 350 -35 135 63.7 351 -35 145 64.8 352 -35 155 61.1 353 -35 165 67.2 354 -35 175 62.0 355 -35 185 68.8 356 -35 195 73.2 364 -35 275 49.7 365 -35 285 58.9 367 -35 305 58.9 368 -35 315 66.8 371 -35 345 71.1 372 -35 355 67.5 379 -45 65 67.5 387 -45 145 64.1 389 -45 165 67.3 390 -45 175 54.1 402 -45 295 44.5 403 -45 305 59.8 417 -55 170 71.1 423 -55 290 62.4 424 -55 310 71.8 425 -55 330 49.8 433 -65 130 85.6