High Level (Cirriform) Amount-When-Present (%) December, January, February (1954 - 1997) , Ship Observations Only Global Average: 35.3 Zonal Averages 17 zones Lat.N Average 85 37.6 75 53.9 65 39.5 55 40.0 45 37.5 35 37.2 25 31.3 15 31.5 5 35.7 -5 35.0 -15 31.7 -25 30.5 -35 32.6 -45 36.9 -55 40.7 -65 41.2 -75 36.3 Grid Box Averages 372 filled boxes Box # Lat.N Lon.E Average 1 85 60 30.4 2 85 180 47.6 3 85 300 36.5 4 75 20 34.8 5 75 60 41.1 7 75 140 57.1 8 75 180 59.0 9 75 220 56.2 13 65 10 36.5 14 65 30 35.5 15 65 50 33.1 21 65 170 39.5 22 65 190 38.7 23 65 210 45.6 29 65 330 43.5 30 65 350 38.6 31 55 10 37.5 32 55 30 40.5 38 55 150 37.2 39 55 170 36.4 40 55 190 34.5 41 55 210 39.1 42 55 230 37.4 46 55 310 50.8 47 55 330 45.5 48 55 350 37.7 49 45 5 37.5 50 45 15 40.1 51 45 25 41.3 52 45 35 45.1 53 45 45 42.0 54 45 55 40.3 62 45 135 36.6 63 45 145 36.7 64 45 155 36.3 65 45 165 30.2 66 45 175 32.5 67 45 185 35.8 68 45 195 35.6 69 45 205 32.5 70 45 215 35.4 71 45 225 38.8 72 45 235 37.5 77 45 285 40.5 78 45 295 44.1 79 45 305 44.5 80 45 315 46.5 81 45 325 39.0 82 45 335 37.7 83 45 345 36.9 84 45 355 37.4 85 35 5 36.1 86 35 15 37.6 87 35 25 37.5 88 35 35 38.6 90 35 55 42.5 96 35 115 32.7 97 35 125 40.4 98 35 135 38.4 99 35 145 32.8 100 35 155 33.3 101 35 165 41.0 102 35 175 32.6 103 35 185 34.3 104 35 195 34.6 105 35 205 34.8 106 35 215 36.1 107 35 225 43.3 108 35 235 38.2 109 35 245 42.2 112 35 275 40.6 113 35 285 39.3 114 35 295 39.8 115 35 305 38.4 116 35 315 39.5 117 35 325 36.3 118 35 335 37.0 119 35 345 36.3 120 35 355 35.2 124 25 35 34.7 125 25 45 36.0 126 25 55 34.8 127 25 65 32.8 128 25 75 37.5 129 25 85 26.9 130 25 95 32.3 132 25 115 35.3 133 25 125 29.8 134 25 135 25.0 135 25 145 23.9 136 25 155 26.4 137 25 165 26.5 138 25 175 26.8 139 25 185 29.1 140 25 195 31.0 141 25 205 33.3 142 25 215 35.1 143 25 225 36.8 144 25 235 34.5 145 25 245 36.0 146 25 255 35.9 147 25 265 33.7 148 25 275 29.2 149 25 285 29.6 150 25 295 28.5 151 25 305 28.9 152 25 315 30.3 153 25 325 30.8 154 25 335 32.6 155 25 345 36.6 160 15 35 31.5 161 15 45 32.4 162 15 55 28.8 163 15 65 28.3 164 15 75 32.4 165 15 85 29.5 166 15 95 30.3 167 15 105 37.5 168 15 115 30.9 169 15 125 31.4 170 15 135 30.0 171 15 145 28.7 172 15 155 32.1 173 15 165 36.1 174 15 175 31.8 175 15 185 32.2 176 15 195 31.6 177 15 205 30.5 178 15 215 30.5 179 15 225 33.8 180 15 235 33.4 181 15 245 32.3 182 15 255 29.8 183 15 265 25.7 184 15 275 25.4 185 15 285 28.8 186 15 295 26.4 187 15 305 26.9 188 15 315 31.1 189 15 325 34.7 190 15 335 42.0 191 15 345 43.5 193 5 5 51.0 197 5 45 29.3 198 5 55 29.2 199 5 65 30.0 200 5 75 34.0 201 5 85 33.2 202 5 95 35.9 203 5 105 38.6 204 5 115 37.3 205 5 125 36.8 206 5 135 37.4 207 5 145 34.9 208 5 155 36.9 209 5 165 48.0 210 5 175 39.0 211 5 185 35.6 212 5 195 35.1 213 5 205 36.4 214 5 215 29.6 215 5 225 25.9 216 5 235 22.3 217 5 245 33.4 218 5 255 30.9 219 5 265 25.5 220 5 275 27.8 221 5 285 33.3 223 5 305 31.7 224 5 315 34.7 225 5 325 37.9 226 5 335 43.5 227 5 345 47.5 228 5 355 46.5 229 -5 5 36.3 230 -5 15 36.2 232 -5 35 31.6 233 -5 45 30.5 234 -5 55 29.8 235 -5 65 33.9 236 -5 75 32.6 237 -5 85 32.6 238 -5 95 34.9 239 -5 105 43.5 240 -5 115 41.5 241 -5 125 41.9 242 -5 135 42.1 243 -5 145 40.1 244 -5 155 38.4 245 -5 165 42.3 246 -5 175 37.0 247 -5 185 34.9 248 -5 195 32.5 249 -5 205 30.2 250 -5 215 26.0 251 -5 225 24.2 252 -5 235 25.5 253 -5 245 24.3 254 -5 255 24.5 255 -5 265 26.4 256 -5 275 34.9 257 -5 285 35.9 260 -5 315 31.6 261 -5 325 30.1 262 -5 335 30.9 263 -5 345 32.6 264 -5 355 33.5 265 -15 5 29.0 266 -15 15 35.1 268 -15 35 30.0 269 -15 45 33.4 270 -15 55 31.7 271 -15 65 31.7 272 -15 75 31.0 273 -15 85 30.7 274 -15 95 30.0 275 -15 105 31.0 276 -15 115 32.1 277 -15 125 40.7 278 -15 135 39.7 279 -15 145 37.0 280 -15 155 31.9 281 -15 165 31.8 282 -15 175 31.0 283 -15 185 35.0 284 -15 195 34.7 285 -15 205 30.3 286 -15 215 28.3 287 -15 225 30.7 288 -15 235 28.7 289 -15 245 29.7 290 -15 255 28.8 291 -15 265 22.3 292 -15 275 30.8 293 -15 285 36.8 297 -15 325 30.1 298 -15 335 29.9 299 -15 345 26.6 300 -15 355 26.4 301 -25 5 27.3 302 -25 15 27.0 304 -25 35 29.6 305 -25 45 30.4 306 -25 55 29.7 307 -25 65 29.8 308 -25 75 28.3 309 -25 85 27.8 310 -25 95 27.6 311 -25 105 31.9 312 -25 115 29.3 315 -25 145 32.3 316 -25 155 29.2 317 -25 165 28.5 318 -25 175 30.9 319 -25 185 31.8 320 -25 195 35.2 321 -25 205 35.9 322 -25 215 36.5 323 -25 225 32.4 324 -25 235 30.4 325 -25 245 28.2 326 -25 255 27.3 327 -25 265 27.9 328 -25 275 29.9 329 -25 285 29.0 332 -25 315 32.2 333 -25 325 30.6 334 -25 335 28.8 335 -25 345 26.2 336 -25 355 26.8 337 -35 5 27.8 338 -35 15 27.9 339 -35 25 28.5 340 -35 35 31.6 341 -35 45 28.1 342 -35 55 32.5 343 -35 65 29.5 344 -35 75 30.9 345 -35 85 30.8 346 -35 95 32.8 347 -35 105 29.8 348 -35 115 29.4 349 -35 125 33.9 350 -35 135 31.5 351 -35 145 30.7 352 -35 155 32.3 353 -35 165 31.2 354 -35 175 30.0 355 -35 185 32.5 356 -35 195 32.9 357 -35 205 29.4 358 -35 215 37.5 359 -35 225 37.8 360 -35 235 35.5 361 -35 245 35.5 362 -35 255 45.3 363 -35 265 28.8 364 -35 275 33.6 365 -35 285 31.8 367 -35 305 31.7 368 -35 315 33.9 369 -35 325 39.1 370 -35 335 33.7 371 -35 345 31.9 372 -35 355 29.5 373 -45 5 44.7 374 -45 15 36.1 375 -45 25 39.9 376 -45 35 35.7 377 -45 45 34.4 378 -45 55 42.6 379 -45 65 36.9 380 -45 75 36.8 381 -45 85 36.7 382 -45 95 35.9 383 -45 105 41.7 384 -45 115 41.6 385 -45 125 40.1 386 -45 135 42.6 387 -45 145 34.2 388 -45 155 33.0 389 -45 165 34.4 390 -45 175 34.1 391 -45 185 34.4 392 -45 195 34.7 393 -45 205 32.7 394 -45 215 34.8 395 -45 225 41.5 400 -45 275 35.7 401 -45 285 32.6 402 -45 295 32.3 403 -45 305 32.0 404 -45 315 35.0 405 -45 325 33.5 406 -45 335 35.1 407 -45 345 43.7 408 -45 355 42.0 409 -55 10 41.6 410 -55 30 47.2 411 -55 50 40.0 412 -55 70 41.5 413 -55 90 50.8 414 -55 110 39.3 415 -55 130 37.9 416 -55 150 42.4 417 -55 170 39.3 418 -55 190 39.8 422 -55 270 36.5 423 -55 290 36.2 424 -55 310 36.7 425 -55 330 37.3 426 -55 350 43.2 427 -65 10 37.3 428 -65 30 38.9 429 -65 50 39.3 430 -65 70 34.8 431 -65 90 38.0 432 -65 110 36.9 433 -65 130 39.6 434 -65 150 37.7 435 -65 170 41.6 436 -65 190 48.0 437 -65 210 43.2 438 -65 230 56.4 441 -65 290 39.8 442 -65 310 39.9 443 -65 330 46.3 444 -65 350 33.9 449 -75 180 39.4 450 -75 220 43.0 452 -75 300 31.0 453 -75 340 30.4