High Level (Cirriform) Amount-When-Present (%) December, January, February (1954 - 1997) Night, Ship Observations Only Global Average: 37.0 Zonal Averages 17 zones Lat.N Average 85 39.6 75 59.0 65 44.1 55 44.4 45 42.1 35 41.0 25 34.3 15 33.8 5 38.6 -5 38.4 -15 33.5 -25 32.3 -35 32.8 -45 33.3 -55 41.2 -65 38.8 -75 34.4 Grid Box Averages 309 filled boxes Box # Lat.N Lon.E Average 1 85 60 34.6 2 85 180 49.3 3 85 300 34.0 4 75 20 37.4 7 75 140 67.4 8 75 180 62.7 9 75 220 56.8 13 65 10 40.4 21 65 170 43.2 29 65 330 51.3 30 65 350 37.6 31 55 10 38.9 32 55 30 41.4 38 55 150 39.8 39 55 170 39.4 40 55 190 36.5 41 55 210 45.1 42 55 230 42.0 46 55 310 58.0 47 55 330 51.3 48 55 350 42.0 49 45 5 36.9 50 45 15 42.3 51 45 25 42.6 52 45 35 45.1 62 45 135 40.2 63 45 145 39.4 64 45 155 39.5 65 45 165 34.1 66 45 175 42.2 67 45 185 39.3 68 45 195 40.4 69 45 205 35.9 70 45 215 40.8 71 45 225 44.2 72 45 235 40.6 77 45 285 43.3 78 45 295 50.0 79 45 305 50.0 80 45 315 51.6 81 45 325 44.0 82 45 335 42.7 83 45 345 42.1 84 45 355 43.2 85 35 5 36.8 86 35 15 41.0 87 35 25 40.8 88 35 35 43.4 97 35 125 42.6 98 35 135 41.4 99 35 145 34.8 100 35 155 38.5 101 35 165 48.4 102 35 175 35.7 103 35 185 36.3 104 35 195 35.7 105 35 205 38.6 106 35 215 40.0 107 35 225 46.4 108 35 235 42.4 109 35 245 44.8 112 35 275 37.8 113 35 285 43.0 114 35 295 45.0 115 35 305 43.9 116 35 315 43.3 117 35 325 40.4 118 35 335 41.4 119 35 345 41.5 120 35 355 39.6 124 25 35 38.1 126 25 55 37.6 127 25 65 35.8 132 25 115 35.7 133 25 125 30.3 134 25 135 27.0 135 25 145 25.4 136 25 155 28.8 137 25 165 30.1 138 25 175 29.0 139 25 185 31.7 140 25 195 34.8 141 25 205 38.1 142 25 215 39.3 143 25 225 41.7 144 25 235 39.1 145 25 245 39.6 146 25 255 39.9 147 25 265 35.6 148 25 275 29.2 149 25 285 32.8 150 25 295 30.1 151 25 305 31.9 152 25 315 34.2 153 25 325 32.7 154 25 335 36.1 155 25 345 40.0 160 15 35 35.2 161 15 45 33.3 162 15 55 31.3 163 15 65 29.0 164 15 75 34.4 165 15 85 31.3 166 15 95 29.2 167 15 105 37.3 168 15 115 32.3 169 15 125 34.2 170 15 135 32.5 171 15 145 30.8 172 15 155 32.7 173 15 165 40.7 174 15 175 33.2 175 15 185 32.7 176 15 195 34.2 177 15 205 35.4 178 15 215 29.9 179 15 225 40.3 180 15 235 38.2 181 15 245 36.0 182 15 255 33.1 183 15 265 26.9 184 15 275 25.6 185 15 285 30.6 186 15 295 26.3 187 15 305 27.9 188 15 315 36.3 189 15 325 37.1 190 15 335 45.8 191 15 345 45.8 193 5 5 50.7 197 5 45 31.3 198 5 55 31.4 199 5 65 31.6 200 5 75 36.4 201 5 85 33.7 202 5 95 35.2 203 5 105 39.1 204 5 115 39.5 205 5 125 41.5 206 5 135 37.8 207 5 145 39.5 208 5 155 39.5 209 5 165 53.2 211 5 185 36.3 212 5 195 34.4 213 5 205 41.1 219 5 265 25.8 220 5 275 27.3 221 5 285 33.3 223 5 305 32.0 224 5 315 37.0 225 5 325 41.6 226 5 335 47.0 227 5 345 48.2 228 5 355 45.8 229 -5 5 36.3 230 -5 15 34.8 233 -5 45 33.8 234 -5 55 31.2 235 -5 65 42.5 236 -5 75 35.7 237 -5 85 33.9 238 -5 95 35.7 239 -5 105 46.6 240 -5 115 44.0 241 -5 125 47.1 242 -5 135 46.4 243 -5 145 43.7 244 -5 155 43.7 245 -5 165 42.3 246 -5 175 36.6 247 -5 185 37.5 248 -5 195 36.0 252 -5 235 28.8 255 -5 265 27.8 256 -5 275 35.0 257 -5 285 36.5 260 -5 315 30.9 261 -5 325 32.6 262 -5 335 33.3 263 -5 345 35.5 264 -5 355 33.8 265 -15 5 30.7 266 -15 15 33.7 268 -15 35 30.1 269 -15 45 35.5 270 -15 55 33.4 271 -15 65 36.5 272 -15 75 33.9 273 -15 85 31.7 274 -15 95 30.1 275 -15 105 32.2 276 -15 115 33.0 277 -15 125 43.4 278 -15 135 43.8 279 -15 145 41.6 280 -15 155 34.5 281 -15 165 31.3 282 -15 175 30.9 283 -15 185 34.8 284 -15 195 36.6 285 -15 205 30.4 286 -15 215 29.5 287 -15 225 33.4 288 -15 235 32.3 289 -15 245 33.8 292 -15 275 31.4 293 -15 285 39.3 297 -15 325 31.9 298 -15 335 29.7 299 -15 345 25.5 300 -15 355 27.8 301 -25 5 29.6 302 -25 15 26.7 304 -25 35 32.6 305 -25 45 34.6 306 -25 55 31.9 307 -25 65 32.5 308 -25 75 27.1 309 -25 85 29.1 310 -25 95 29.6 311 -25 105 33.4 312 -25 115 29.4 316 -25 155 31.9 317 -25 165 28.6 318 -25 175 31.7 319 -25 185 30.1 320 -25 195 38.7 321 -25 205 39.2 322 -25 215 39.3 323 -25 225 37.3 324 -25 235 31.8 325 -25 245 27.4 329 -25 285 26.4 332 -25 315 33.9 333 -25 325 30.4 334 -25 335 28.9 335 -25 345 27.4 336 -25 355 31.4 337 -35 5 30.6 338 -35 15 28.6 339 -35 25 29.5 340 -35 35 36.0 341 -35 45 27.9 342 -35 55 38.2 343 -35 65 31.4 344 -35 75 31.2 345 -35 85 32.5 346 -35 95 33.7 347 -35 105 30.3 348 -35 115 29.6 349 -35 125 36.5 350 -35 135 31.8 351 -35 145 31.1 352 -35 155 34.9 353 -35 165 31.7 354 -35 175 30.4 355 -35 185 30.9 356 -35 195 32.9 357 -35 205 27.3 358 -35 215 42.4 363 -35 265 30.1 364 -35 275 34.8 365 -35 285 30.4 367 -35 305 32.6 368 -35 315 36.6 369 -35 325 42.8 370 -35 335 34.0 371 -35 345 31.5 372 -35 355 31.8 374 -45 15 33.6 380 -45 75 33.8 387 -45 145 33.5 388 -45 155 30.8 389 -45 165 32.2 390 -45 175 33.3 391 -45 185 33.3 392 -45 195 34.0 400 -45 275 36.5 401 -45 285 33.6 402 -45 295 30.9 403 -45 305 29.7 404 -45 315 37.3 409 -55 10 44.9 411 -55 50 39.3 412 -55 70 42.7 413 -55 90 55.0 415 -55 130 38.9 416 -55 150 44.9 417 -55 170 39.1 423 -55 290 34.1 424 -55 310 35.2 425 -55 330 36.3 427 -65 10 35.5 428 -65 30 38.7 429 -65 50 38.6 430 -65 70 33.6 431 -65 90 39.3 432 -65 110 38.9 433 -65 130 39.4 434 -65 150 38.1 435 -65 170 44.5 437 -65 210 45.6 441 -65 290 38.8 442 -65 310 38.2 444 -65 350 33.9 449 -75 180 39.7 452 -75 300 31.0 453 -75 340 30.3