High Level (Cirriform) Amount-When-Present (%) September, October, November (1954 - 1997) Day, Ship Observations Only Global Average: 33.1 Zonal Averages 17 zones Lat.N Average 85 33.4 75 43.6 65 36.8 55 35.1 45 32.1 35 31.3 25 28.3 15 31.7 5 31.6 -5 32.0 -15 29.3 -25 30.0 -35 32.7 -45 36.7 -55 41.7 -65 36.2 -75 46.0 Grid Box Averages 336 filled boxes Box # Lat.N Lon.E Average 1 85 60 23.9 2 85 180 47.2 3 85 300 24.4 4 75 20 34.1 5 75 60 37.6 6 75 100 37.0 7 75 140 46.4 8 75 180 53.1 9 75 220 48.1 10 75 260 41.4 11 75 300 39.2 12 75 340 37.4 13 65 10 32.2 14 65 30 33.0 15 65 50 35.1 20 65 150 36.2 21 65 170 33.7 22 65 190 38.5 23 65 210 38.7 25 65 250 42.8 26 65 270 40.1 27 65 290 44.7 28 65 310 34.6 29 65 330 33.8 30 65 350 36.2 31 55 10 35.8 32 55 30 40.3 38 55 150 34.1 39 55 170 33.4 40 55 190 32.4 41 55 210 34.3 42 55 230 32.1 44 55 270 41.4 45 55 290 41.5 46 55 310 36.9 47 55 330 37.6 48 55 350 33.6 49 45 5 33.9 50 45 15 35.8 51 45 25 37.6 52 45 35 35.4 53 45 45 34.1 54 45 55 33.2 62 45 135 33.9 63 45 145 33.7 64 45 155 31.1 65 45 165 28.0 66 45 175 28.4 67 45 185 30.9 68 45 195 30.5 69 45 205 28.8 70 45 215 30.4 71 45 225 33.0 72 45 235 31.6 77 45 285 36.3 78 45 295 36.2 79 45 305 36.3 80 45 315 37.6 81 45 325 33.4 82 45 335 32.1 83 45 345 31.3 84 45 355 32.1 85 35 5 33.1 86 35 15 32.6 87 35 25 33.0 88 35 35 33.1 90 35 55 32.2 96 35 115 38.8 97 35 125 33.8 98 35 135 33.4 99 35 145 30.6 100 35 155 29.6 101 35 165 34.3 102 35 175 30.7 103 35 185 30.6 104 35 195 31.5 105 35 205 29.2 106 35 215 27.7 107 35 225 32.5 108 35 235 30.8 109 35 245 35.6 112 35 275 36.6 113 35 285 35.1 114 35 295 33.7 115 35 305 30.3 116 35 315 31.8 117 35 325 29.2 118 35 335 30.2 119 35 345 30.6 120 35 355 31.7 124 25 35 33.4 125 25 45 40.9 126 25 55 33.7 127 25 65 29.9 128 25 75 29.6 129 25 85 32.3 131 25 105 39.4 132 25 115 33.8 133 25 125 30.8 134 25 135 25.6 135 25 145 25.3 136 25 155 26.8 137 25 165 27.4 138 25 175 27.6 139 25 185 28.3 140 25 195 28.8 141 25 205 29.1 142 25 215 27.6 143 25 225 29.2 144 25 235 25.6 145 25 245 27.6 146 25 255 27.4 147 25 265 28.6 148 25 275 28.1 149 25 285 28.5 150 25 295 28.2 151 25 305 27.6 152 25 315 27.4 153 25 325 28.8 154 25 335 32.6 155 25 345 36.0 160 15 35 34.7 161 15 45 31.3 162 15 55 29.2 163 15 65 29.1 164 15 75 33.9 165 15 85 33.0 166 15 95 33.3 167 15 105 41.2 168 15 115 33.9 169 15 125 31.3 170 15 135 29.7 171 15 145 27.9 172 15 155 31.7 173 15 165 32.7 174 15 175 31.3 175 15 185 32.6 176 15 195 34.0 177 15 205 32.5 178 15 215 28.6 179 15 225 30.6 180 15 235 28.9 181 15 245 28.0 182 15 255 29.3 183 15 265 30.1 184 15 275 30.7 185 15 285 31.6 186 15 295 28.3 187 15 305 28.9 188 15 315 32.2 189 15 325 38.4 190 15 335 41.3 191 15 345 43.2 193 5 5 33.5 197 5 45 24.8 198 5 55 27.3 199 5 65 30.5 200 5 75 34.6 201 5 85 35.3 202 5 95 39.6 203 5 105 39.8 204 5 115 38.3 205 5 125 34.4 206 5 135 33.3 207 5 145 28.2 208 5 155 28.3 209 5 165 35.8 210 5 175 32.3 211 5 185 29.3 212 5 195 30.6 213 5 205 28.3 214 5 215 29.3 215 5 225 25.0 216 5 235 22.4 217 5 245 27.1 218 5 255 30.8 219 5 265 28.5 220 5 275 36.1 221 5 285 41.6 223 5 305 26.4 224 5 315 25.6 225 5 325 28.2 226 5 335 31.4 227 5 345 35.0 228 5 355 31.4 229 -5 5 36.6 230 -5 15 35.8 232 -5 35 27.8 233 -5 45 23.4 234 -5 55 29.3 235 -5 65 32.4 236 -5 75 32.3 237 -5 85 36.2 238 -5 95 39.4 239 -5 105 42.2 240 -5 115 35.8 241 -5 125 33.8 242 -5 135 33.9 243 -5 145 35.2 244 -5 155 33.1 245 -5 165 31.8 246 -5 175 31.1 247 -5 185 29.2 248 -5 195 30.4 249 -5 205 31.2 250 -5 215 25.4 251 -5 225 21.1 252 -5 235 18.7 253 -5 245 21.4 254 -5 255 23.7 255 -5 265 24.9 256 -5 275 36.8 257 -5 285 44.4 260 -5 315 27.0 261 -5 325 25.4 262 -5 335 25.8 263 -5 345 26.3 264 -5 355 28.9 265 -15 5 33.2 266 -15 15 33.8 268 -15 35 29.9 269 -15 45 24.5 270 -15 55 24.8 271 -15 65 28.0 272 -15 75 29.3 273 -15 85 30.0 274 -15 95 31.2 275 -15 105 27.5 276 -15 115 28.3 277 -15 125 32.0 278 -15 135 34.9 279 -15 145 31.1 280 -15 155 28.6 281 -15 165 32.3 282 -15 175 29.7 283 -15 185 32.8 284 -15 195 31.0 285 -15 205 29.1 286 -15 215 24.9 287 -15 225 24.7 288 -15 235 24.6 289 -15 245 25.3 290 -15 255 23.4 292 -15 275 36.9 293 -15 285 41.5 297 -15 325 27.7 298 -15 335 27.2 299 -15 345 27.8 300 -15 355 31.4 301 -25 5 29.1 302 -25 15 30.9 304 -25 35 30.6 305 -25 45 27.9 306 -25 55 24.9 307 -25 65 26.4 308 -25 75 21.4 309 -25 85 26.7 310 -25 95 26.9 311 -25 105 27.3 312 -25 115 26.7 315 -25 145 22.3 316 -25 155 26.0 317 -25 165 27.2 318 -25 175 29.1 319 -25 185 33.4 320 -25 195 34.2 321 -25 205 35.4 322 -25 215 30.2 323 -25 225 31.2 324 -25 235 33.0 325 -25 245 29.3 326 -25 255 28.4 328 -25 275 29.9 329 -25 285 32.4 332 -25 315 37.2 333 -25 325 34.5 334 -25 335 30.0 335 -25 345 28.8 336 -25 355 29.1 337 -35 5 32.3 338 -35 15 30.6 339 -35 25 33.7 340 -35 35 32.8 341 -35 45 29.0 342 -35 55 29.6 343 -35 65 31.0 344 -35 75 30.6 345 -35 85 28.2 346 -35 95 29.3 347 -35 105 32.3 348 -35 115 33.3 349 -35 125 33.3 350 -35 135 34.9 351 -35 145 34.2 352 -35 155 32.4 353 -35 165 30.6 354 -35 175 29.8 355 -35 185 33.0 356 -35 195 34.4 357 -35 205 34.4 358 -35 215 37.9 359 -35 225 36.8 360 -35 235 35.8 364 -35 275 34.9 365 -35 285 31.5 366 -35 295 38.5 367 -35 305 32.8 368 -35 315 34.5 369 -35 325 31.3 370 -35 335 34.4 371 -35 345 31.3 372 -35 355 33.8 379 -45 65 40.4 380 -45 75 37.1 386 -45 135 39.3 387 -45 145 38.0 388 -45 155 37.1 389 -45 165 33.0 390 -45 175 31.9 391 -45 185 34.3 392 -45 195 36.4 400 -45 275 33.9 401 -45 285 36.0 402 -45 295 34.5 403 -45 305 39.5 404 -45 315 37.1 405 -45 325 40.7 416 -55 150 54.1 417 -55 170 39.8 423 -55 290 38.8 424 -55 310 40.1 425 -55 330 37.0 430 -65 70 35.1 432 -65 110 32.1 442 -65 310 40.1 449 -75 180 46.0