High Level (Cirriform) Frequency of Occurrence (%) December (1953 - 1996) Day, Ship Observations Only Global Average: 40.0 Zonal Averages 17 zones Lat.N Average 85 48.1 75 44.3 65 31.0 55 36.1 45 36.8 35 37.2 25 32.0 15 35.5 5 48.9 -5 44.6 -15 40.4 -25 38.3 -35 39.4 -45 38.7 -55 39.8 -65 44.4 -75 50.1 Grid Box Averages 363 filled boxes Box # Lat.N Lon.E Average 2 85 180 48.1 4 75 20 21.2 5 75 60 24.6 8 75 180 47.1 9 75 220 81.7 13 65 10 30.0 14 65 30 29.0 15 65 50 22.2 21 65 170 26.5 22 65 190 18.4 23 65 210 28.7 27 65 290 35.4 28 65 310 35.1 29 65 330 36.3 30 65 350 33.8 31 55 10 36.8 32 55 30 30.2 38 55 150 29.4 39 55 170 34.5 40 55 190 36.8 41 55 210 35.7 42 55 230 42.5 46 55 310 31.6 47 55 330 37.1 48 55 350 45.4 49 45 5 44.0 50 45 15 36.4 51 45 25 33.7 52 45 35 33.4 53 45 45 34.4 54 45 55 34.8 62 45 135 25.6 63 45 145 27.7 64 45 155 30.8 65 45 165 32.2 66 45 175 32.6 67 45 185 35.6 68 45 195 35.3 69 45 205 39.9 70 45 215 42.3 71 45 225 43.4 72 45 235 46.3 77 45 285 37.3 78 45 295 33.2 79 45 305 36.6 80 45 315 39.8 81 45 325 40.2 82 45 335 40.0 83 45 345 37.0 84 45 355 37.8 85 35 5 39.7 86 35 15 34.1 87 35 25 32.3 88 35 35 34.9 90 35 55 37.6 96 35 115 17.5 97 35 125 20.8 98 35 135 26.0 99 35 145 27.3 100 35 155 30.8 101 35 165 33.0 102 35 175 32.9 103 35 185 37.9 104 35 195 37.7 105 35 205 43.9 106 35 215 45.3 107 35 225 42.9 108 35 235 38.9 109 35 245 39.5 112 35 275 45.3 113 35 285 40.4 114 35 295 38.5 115 35 305 40.9 116 35 315 44.8 117 35 325 45.0 118 35 335 41.9 119 35 345 34.6 120 35 355 36.3 124 25 35 28.3 125 25 45 31.0 126 25 55 29.2 127 25 65 26.4 128 25 75 21.8 129 25 85 26.3 132 25 115 25.4 133 25 125 24.2 134 25 135 24.6 135 25 145 28.5 136 25 155 26.7 137 25 165 24.5 138 25 175 24.3 139 25 185 25.9 140 25 195 30.7 141 25 205 32.8 142 25 215 37.4 143 25 225 38.0 144 25 235 37.6 145 25 245 41.9 146 25 255 49.5 147 25 265 43.4 148 25 275 38.7 149 25 285 35.0 150 25 295 31.4 151 25 305 31.4 152 25 315 35.8 153 25 325 36.1 154 25 335 31.4 155 25 345 33.4 160 15 35 20.6 161 15 45 18.4 162 15 55 19.3 163 15 65 29.0 164 15 75 38.4 165 15 85 40.9 166 15 95 45.8 167 15 105 38.8 168 15 115 39.5 169 15 125 44.0 170 15 135 43.1 171 15 145 39.6 172 15 155 31.5 173 15 165 22.4 174 15 175 22.9 175 15 185 24.4 176 15 195 28.3 177 15 205 31.3 178 15 215 37.9 179 15 225 39.5 180 15 235 41.5 181 15 245 48.3 182 15 255 48.6 183 15 265 37.9 184 15 275 39.1 185 15 285 37.9 186 15 295 33.3 187 15 305 30.1 188 15 315 31.6 189 15 325 36.0 190 15 335 40.2 191 15 345 46.7 193 5 5 37.0 197 5 45 27.4 198 5 55 27.6 199 5 65 41.3 200 5 75 49.5 201 5 85 57.6 202 5 95 62.8 203 5 105 62.6 204 5 115 65.3 205 5 125 66.4 206 5 135 68.8 207 5 145 65.4 208 5 155 65.5 209 5 165 58.2 210 5 175 54.8 211 5 185 59.4 212 5 195 50.6 213 5 205 41.9 214 5 215 43.8 215 5 225 42.9 216 5 235 42.3 217 5 245 42.3 218 5 255 34.5 219 5 265 33.0 220 5 275 40.3 221 5 285 52.0 223 5 305 45.8 224 5 315 47.2 225 5 325 42.4 226 5 335 44.5 227 5 345 41.9 228 5 355 36.7 229 -5 5 31.8 230 -5 15 46.3 232 -5 35 51.2 233 -5 45 36.5 234 -5 55 43.2 235 -5 65 49.5 236 -5 75 58.8 237 -5 85 65.1 238 -5 95 61.5 239 -5 105 72.8 240 -5 115 79.2 241 -5 125 73.6 242 -5 135 69.0 243 -5 145 71.6 244 -5 155 69.2 245 -5 165 64.7 246 -5 175 68.7 247 -5 185 64.3 248 -5 195 48.6 249 -5 205 40.9 250 -5 215 35.7 251 -5 225 30.9 252 -5 235 21.1 253 -5 245 17.2 254 -5 255 15.6 255 -5 265 15.1 256 -5 275 30.7 257 -5 285 37.4 260 -5 315 43.3 261 -5 325 38.6 262 -5 335 31.2 263 -5 345 19.4 264 -5 355 18.6 265 -15 5 17.5 266 -15 15 29.8 268 -15 35 50.0 269 -15 45 55.1 270 -15 55 50.4 271 -15 65 42.9 272 -15 75 49.0 273 -15 85 42.9 274 -15 95 44.2 275 -15 105 38.4 276 -15 115 40.5 277 -15 125 54.7 278 -15 135 64.0 279 -15 145 51.6 280 -15 155 47.4 281 -15 165 49.7 282 -15 175 52.5 283 -15 185 56.5 284 -15 195 54.0 285 -15 205 53.1 286 -15 215 53.1 287 -15 225 39.8 288 -15 235 30.2 289 -15 245 29.8 290 -15 255 20.8 291 -15 265 21.8 292 -15 275 22.5 293 -15 285 39.7 297 -15 325 49.7 298 -15 335 31.3 299 -15 345 27.0 300 -15 355 17.5 301 -25 5 15.8 302 -25 15 16.9 304 -25 35 38.6 305 -25 45 40.8 306 -25 55 50.8 307 -25 65 37.4 308 -25 75 31.5 309 -25 85 32.3 310 -25 95 28.0 311 -25 105 24.1 312 -25 115 23.1 315 -25 145 31.6 316 -25 155 35.5 317 -25 165 39.7 318 -25 175 40.1 319 -25 185 42.4 320 -25 195 45.8 321 -25 205 47.9 322 -25 215 56.9 323 -25 225 58.1 324 -25 235 49.0 325 -25 245 41.7 326 -25 255 42.1 327 -25 265 36.7 328 -25 275 22.0 329 -25 285 24.6 332 -25 315 51.4 333 -25 325 52.1 334 -25 335 47.3 335 -25 345 38.9 336 -25 355 23.6 337 -35 5 34.7 338 -35 15 28.4 339 -35 25 33.5 340 -35 35 36.9 341 -35 45 35.7 342 -35 55 37.5 343 -35 65 36.4 344 -35 75 37.5 345 -35 85 40.3 346 -35 95 32.8 347 -35 105 30.8 348 -35 115 31.6 349 -35 125 39.3 350 -35 135 40.3 351 -35 145 40.8 352 -35 155 38.6 353 -35 165 39.7 354 -35 175 44.2 355 -35 185 46.3 356 -35 195 40.8 357 -35 205 44.9 358 -35 215 43.4 359 -35 225 42.8 360 -35 235 44.6 361 -35 245 47.5 362 -35 255 56.6 363 -35 265 41.1 364 -35 275 25.5 365 -35 285 22.6 367 -35 305 40.1 368 -35 315 38.9 369 -35 325 36.1 370 -35 335 46.0 371 -35 345 50.1 372 -35 355 45.8 373 -45 5 38.9 374 -45 15 40.8 375 -45 25 41.6 376 -45 35 39.3 377 -45 45 34.0 378 -45 55 31.6 379 -45 65 31.3 380 -45 75 44.2 381 -45 85 50.1 382 -45 95 37.5 383 -45 105 32.6 384 -45 115 40.1 385 -45 125 43.1 386 -45 135 39.5 387 -45 145 47.0 388 -45 155 44.4 389 -45 165 43.1 390 -45 175 49.1 391 -45 185 47.4 392 -45 195 41.6 393 -45 205 39.9 394 -45 215 34.5 400 -45 275 25.1 401 -45 285 36.9 402 -45 295 44.8 403 -45 305 45.3 404 -45 315 39.5 405 -45 325 32.0 406 -45 335 30.4 407 -45 345 29.7 408 -45 355 29.0 409 -55 10 36.8 410 -55 30 37.0 411 -55 50 40.5 412 -55 70 33.2 413 -55 90 38.5 414 -55 110 37.0 415 -55 130 45.7 416 -55 150 39.1 417 -55 170 35.4 421 -55 250 43.2 422 -55 270 46.6 423 -55 290 54.9 424 -55 310 46.0 425 -55 330 33.3 426 -55 350 31.9 428 -65 30 44.7 429 -65 50 43.1 430 -65 70 39.2 431 -65 90 35.5 432 -65 110 45.3 433 -65 130 54.3 434 -65 150 36.5 435 -65 170 38.0 436 -65 190 42.8 441 -65 290 59.9 442 -65 310 45.1 444 -65 350 48.6 449 -75 180 42.2 453 -75 340 62.7