High Level (Cirriform) Frequency of Occurrence (%) January (1954 - 1997) Day, Ship Observations Only Global Average: 39.1 Zonal Averages 17 zones Lat.N Average 85 48.2 75 45.4 65 31.9 55 36.1 45 36.8 35 36.7 25 30.2 15 30.6 5 44.7 -5 45.3 -15 43.3 -25 37.4 -35 36.6 -45 38.9 -55 41.2 -65 43.1 -75 55.1 Grid Box Averages 365 filled boxes Box # Lat.N Lon.E Average 2 85 180 48.2 4 75 20 27.3 5 75 60 16.8 8 75 180 54.0 9 75 220 79.6 13 65 10 31.4 14 65 30 29.3 15 65 50 22.0 21 65 170 23.2 22 65 190 18.9 23 65 210 38.5 29 65 330 45.2 30 65 350 33.5 31 55 10 35.6 32 55 30 29.1 38 55 150 32.1 39 55 170 33.9 40 55 190 32.0 41 55 210 38.0 42 55 230 42.9 46 55 310 33.5 47 55 330 36.5 48 55 350 46.1 49 45 5 43.6 50 45 15 35.7 51 45 25 27.6 52 45 35 27.1 53 45 45 30.1 54 45 55 30.6 62 45 135 24.2 63 45 145 26.6 64 45 155 29.6 65 45 165 31.2 66 45 175 34.6 67 45 185 37.8 68 45 195 35.9 69 45 205 41.7 70 45 215 41.6 71 45 225 43.9 72 45 235 47.7 77 45 285 36.7 78 45 295 34.8 79 45 305 36.9 80 45 315 38.4 81 45 325 38.9 82 45 335 40.6 83 45 345 38.7 84 45 355 37.6 85 35 5 38.9 86 35 15 33.0 87 35 25 31.3 88 35 35 31.2 90 35 55 41.3 96 35 115 32.2 97 35 125 22.2 98 35 135 27.4 99 35 145 26.0 100 35 155 27.3 101 35 165 29.8 102 35 175 31.0 103 35 185 33.7 104 35 195 35.4 105 35 205 41.7 106 35 215 46.3 107 35 225 44.4 108 35 235 41.8 109 35 245 43.5 112 35 275 42.8 113 35 285 38.9 114 35 295 38.5 115 35 305 42.2 116 35 315 44.6 117 35 325 43.6 118 35 335 42.5 119 35 345 38.9 120 35 355 39.8 124 25 35 24.0 125 25 45 32.7 126 25 55 26.6 127 25 65 22.9 128 25 75 15.9 129 25 85 28.7 132 25 115 22.8 133 25 125 24.0 134 25 135 22.3 135 25 145 23.4 136 25 155 23.6 137 25 165 22.8 138 25 175 22.1 139 25 185 24.2 140 25 195 26.5 141 25 205 29.7 142 25 215 37.5 143 25 225 41.0 144 25 235 43.3 145 25 245 43.0 146 25 255 46.8 147 25 265 42.4 148 25 275 37.4 149 25 285 32.8 150 25 295 27.8 151 25 305 28.6 152 25 315 31.3 153 25 325 30.4 154 25 335 30.1 155 25 345 32.1 160 15 35 22.9 161 15 45 19.7 162 15 55 18.3 163 15 65 22.8 164 15 75 31.9 165 15 85 32.4 166 15 95 38.5 167 15 105 37.8 168 15 115 35.9 169 15 125 39.7 170 15 135 40.7 171 15 145 39.5 172 15 155 33.5 173 15 165 22.9 174 15 175 19.6 175 15 185 20.1 176 15 195 22.3 177 15 205 28.2 178 15 215 32.3 179 15 225 35.3 180 15 235 40.9 181 15 245 42.8 182 15 255 40.4 183 15 265 27.6 184 15 275 30.7 185 15 285 27.2 186 15 295 23.1 187 15 305 21.9 188 15 315 24.3 189 15 325 28.7 190 15 335 34.8 191 15 345 38.9 193 5 5 39.5 197 5 45 28.9 198 5 55 27.3 199 5 65 36.2 200 5 75 44.8 201 5 85 56.4 202 5 95 60.7 203 5 105 58.8 204 5 115 61.0 205 5 125 64.8 206 5 135 71.7 207 5 145 62.6 208 5 155 63.3 209 5 165 55.9 210 5 175 56.8 211 5 185 52.9 212 5 195 41.1 213 5 205 39.9 214 5 215 29.5 215 5 225 33.7 216 5 235 27.4 217 5 245 31.4 218 5 255 30.0 219 5 265 29.2 220 5 275 35.6 221 5 285 39.8 223 5 305 38.4 224 5 315 47.9 225 5 325 44.4 226 5 335 40.7 227 5 345 34.3 228 5 355 35.3 229 -5 5 34.4 230 -5 15 42.8 232 -5 35 46.6 233 -5 45 43.1 234 -5 55 49.5 235 -5 65 57.4 236 -5 75 64.3 237 -5 85 64.2 238 -5 95 67.4 239 -5 105 72.8 240 -5 115 75.3 241 -5 125 72.6 242 -5 135 74.2 243 -5 145 75.3 244 -5 155 71.0 245 -5 165 70.5 246 -5 175 66.4 247 -5 185 56.6 248 -5 195 44.5 249 -5 205 34.5 250 -5 215 28.3 251 -5 225 22.7 252 -5 235 22.0 253 -5 245 16.5 254 -5 255 14.3 255 -5 265 14.7 256 -5 275 35.9 257 -5 285 36.9 260 -5 315 56.9 261 -5 325 42.4 262 -5 335 30.5 263 -5 345 22.3 264 -5 355 22.0 265 -15 5 25.1 266 -15 15 36.5 268 -15 35 52.5 269 -15 45 64.4 270 -15 55 54.2 271 -15 65 49.6 272 -15 75 48.7 273 -15 85 46.4 274 -15 95 43.7 275 -15 105 45.1 276 -15 115 44.4 277 -15 125 60.8 278 -15 135 67.8 279 -15 145 59.5 280 -15 155 54.6 281 -15 165 55.2 282 -15 175 60.5 283 -15 185 62.2 284 -15 195 59.4 285 -15 205 58.7 286 -15 215 50.9 287 -15 225 36.9 288 -15 235 36.7 289 -15 245 29.6 290 -15 255 24.0 291 -15 265 22.2 292 -15 275 23.3 293 -15 285 41.1 297 -15 325 44.8 298 -15 335 24.1 299 -15 345 22.8 300 -15 355 21.8 301 -25 5 15.2 302 -25 15 16.9 304 -25 35 37.5 305 -25 45 41.1 306 -25 55 46.2 307 -25 65 41.6 308 -25 75 37.4 309 -25 85 27.5 310 -25 95 22.5 311 -25 105 26.8 312 -25 115 28.7 315 -25 145 44.2 316 -25 155 39.6 317 -25 165 38.4 318 -25 175 43.4 319 -25 185 44.4 320 -25 195 50.7 321 -25 205 56.9 322 -25 215 55.3 323 -25 225 54.1 324 -25 235 43.3 325 -25 245 39.0 326 -25 255 38.3 327 -25 265 24.9 328 -25 275 23.2 329 -25 285 25.9 332 -25 315 50.8 333 -25 325 49.2 334 -25 335 41.6 335 -25 345 31.1 336 -25 355 20.3 337 -35 5 29.8 338 -35 15 21.3 339 -35 25 28.8 340 -35 35 33.0 341 -35 45 34.2 342 -35 55 34.8 343 -35 65 36.0 344 -35 75 36.8 345 -35 85 34.0 346 -35 95 31.7 347 -35 105 31.3 348 -35 115 28.6 349 -35 125 34.4 350 -35 135 35.8 351 -35 145 35.7 352 -35 155 36.3 353 -35 165 36.6 354 -35 175 40.8 355 -35 185 43.6 356 -35 195 40.8 357 -35 205 44.6 358 -35 215 46.7 359 -35 225 50.8 360 -35 235 51.6 361 -35 245 35.5 362 -35 255 33.6 363 -35 265 31.4 364 -35 275 22.6 365 -35 285 18.0 367 -35 305 41.2 368 -35 315 37.8 369 -35 325 43.1 370 -35 335 45.0 371 -35 345 44.5 372 -35 355 38.9 373 -45 5 31.0 374 -45 15 33.7 375 -45 25 31.7 376 -45 35 42.2 377 -45 45 32.4 378 -45 55 39.2 379 -45 65 39.3 380 -45 75 41.3 381 -45 85 32.8 382 -45 95 42.2 383 -45 105 38.5 384 -45 115 35.1 385 -45 125 32.2 386 -45 135 39.0 387 -45 145 44.5 388 -45 155 42.7 389 -45 165 46.7 390 -45 175 48.6 391 -45 185 42.6 392 -45 195 42.8 393 -45 205 44.9 394 -45 215 45.7 395 -45 225 42.4 397 -45 245 30.8 400 -45 275 24.7 401 -45 285 25.8 402 -45 295 47.3 403 -45 305 47.6 404 -45 315 43.0 405 -45 325 43.3 406 -45 335 36.0 408 -45 355 36.1 409 -55 10 41.7 410 -55 30 37.0 411 -55 50 37.4 412 -55 70 41.1 413 -55 90 48.3 414 -55 110 38.9 415 -55 130 42.1 416 -55 150 37.1 417 -55 170 34.6 418 -55 190 42.1 422 -55 270 35.4 423 -55 290 58.5 424 -55 310 44.6 425 -55 330 36.1 426 -55 350 45.6 427 -65 10 34.6 428 -65 30 50.3 429 -65 50 47.6 430 -65 70 37.9 431 -65 90 39.6 432 -65 110 47.9 433 -65 130 50.4 434 -65 150 45.3 435 -65 170 35.5 436 -65 190 38.5 437 -65 210 39.1 441 -65 290 60.0 442 -65 310 47.2 444 -65 350 35.7 449 -75 180 51.2 452 -75 300 63.4 453 -75 340 53.7