High Level (Cirriform) Frequency of Occurrence (%) June, July, August (1954 - 1997) Day, Ship Observations Only Global Average: 38.7 Zonal Averages 15 zones Lat.N Average 85 54.7 75 49.0 65 49.8 55 49.4 45 46.9 35 39.7 25 39.5 15 48.9 5 54.0 -5 39.4 -15 27.2 -25 27.5 -35 32.1 -45 32.9 -55 30.6 Grid Box Averages 368 filled boxes Box # Lat.N Lon.E Average 1 85 60 49.2 2 85 180 58.3 3 85 300 57.3 4 75 20 42.8 5 75 60 44.3 6 75 100 44.1 7 75 140 48.7 8 75 180 51.8 9 75 220 56.2 10 75 260 54.3 11 75 300 55.1 12 75 340 45.2 13 65 10 44.8 14 65 30 43.9 15 65 50 42.4 16 65 70 43.7 20 65 150 47.0 21 65 170 42.5 22 65 190 49.0 23 65 210 54.7 24 65 230 41.2 25 65 250 57.9 26 65 270 56.4 27 65 290 59.5 28 65 310 57.2 29 65 330 49.5 30 65 350 45.8 31 55 10 46.1 32 55 30 44.4 37 55 130 43.9 38 55 150 44.5 39 55 170 46.2 40 55 190 50.5 41 55 210 50.7 42 55 230 50.6 44 55 270 57.1 45 55 290 61.2 46 55 310 52.5 47 55 330 47.3 48 55 350 51.3 49 45 5 37.7 50 45 15 25.8 51 45 25 15.8 52 45 35 15.4 53 45 45 24.9 54 45 55 22.9 61 45 125 36.3 62 45 135 48.1 63 45 145 47.3 64 45 155 52.8 65 45 165 52.1 66 45 175 52.0 67 45 185 54.3 68 45 195 53.2 69 45 205 51.1 70 45 215 50.5 71 45 225 43.4 72 45 235 37.6 77 45 285 47.2 78 45 295 52.1 79 45 305 50.8 80 45 315 49.3 81 45 325 44.9 82 45 335 42.0 83 45 345 40.0 84 45 355 40.8 85 35 5 26.2 86 35 15 16.8 87 35 25 9.2 88 35 35 7.6 89 35 45 25.7 90 35 55 25.8 96 35 115 38.9 97 35 125 46.1 98 35 135 57.6 99 35 145 55.0 100 35 155 54.1 101 35 165 56.4 102 35 175 50.8 103 35 185 49.3 104 35 195 45.1 105 35 205 42.9 106 35 215 38.1 107 35 225 30.8 108 35 235 25.2 109 35 245 20.3 112 35 275 58.3 113 35 285 50.8 114 35 295 47.6 115 35 305 43.7 116 35 315 38.6 117 35 325 32.4 118 35 335 29.0 119 35 345 19.8 120 35 355 23.3 124 25 35 14.7 125 25 45 6.8 126 25 55 17.8 127 25 65 30.3 128 25 75 40.0 129 25 85 63.9 130 25 95 65.9 131 25 105 57.3 132 25 115 57.5 133 25 125 56.6 134 25 135 60.3 135 25 145 56.9 136 25 155 52.7 137 25 165 50.5 138 25 175 46.8 139 25 185 42.3 140 25 195 34.9 141 25 205 31.3 142 25 215 28.9 143 25 225 29.4 144 25 235 28.8 145 25 245 36.0 146 25 255 51.3 147 25 265 52.1 148 25 275 57.0 149 25 285 50.4 150 25 295 42.4 151 25 305 34.1 152 25 315 26.0 153 25 325 20.5 154 25 335 18.0 155 25 345 18.7 156 25 355 29.3 160 15 35 26.4 161 15 45 30.6 162 15 55 32.9 163 15 65 44.5 164 15 75 56.6 165 15 85 63.0 166 15 95 64.4 167 15 105 69.6 168 15 115 64.3 169 15 125 65.0 170 15 135 65.8 171 15 145 62.4 172 15 155 56.8 173 15 165 49.4 174 15 175 46.4 175 15 185 44.6 176 15 195 39.6 177 15 205 37.0 178 15 215 40.7 179 15 225 41.1 180 15 235 42.3 181 15 245 49.2 182 15 255 64.0 183 15 265 70.9 184 15 275 64.8 185 15 285 53.3 186 15 295 46.1 187 15 305 38.5 188 15 315 33.6 189 15 325 31.3 190 15 335 33.5 191 15 345 41.0 193 5 5 44.6 197 5 45 42.4 198 5 55 43.6 199 5 65 58.3 200 5 75 64.9 201 5 85 68.1 202 5 95 72.8 203 5 105 65.5 204 5 115 69.8 205 5 125 67.7 206 5 135 72.8 207 5 145 68.5 208 5 155 66.7 209 5 165 62.0 210 5 175 63.6 211 5 185 55.3 212 5 195 51.9 213 5 205 45.3 214 5 215 45.4 215 5 225 39.7 216 5 235 41.5 217 5 245 44.3 218 5 255 49.1 219 5 265 56.0 220 5 275 67.4 221 5 285 67.5 222 5 295 51.9 223 5 305 47.1 224 5 315 40.0 225 5 325 31.4 226 5 335 39.4 227 5 345 42.4 228 5 355 33.1 229 -5 5 26.0 230 -5 15 19.9 232 -5 35 21.8 233 -5 45 35.8 234 -5 55 50.8 235 -5 65 61.8 236 -5 75 61.8 237 -5 85 68.7 238 -5 95 64.5 239 -5 105 54.4 240 -5 115 47.0 241 -5 125 46.7 242 -5 135 45.0 243 -5 145 60.8 244 -5 155 62.6 245 -5 165 58.0 246 -5 175 55.9 247 -5 185 49.5 248 -5 195 40.5 249 -5 205 34.6 250 -5 215 28.5 251 -5 225 16.9 252 -5 235 14.7 253 -5 245 17.9 254 -5 255 23.8 255 -5 265 26.1 256 -5 275 30.7 257 -5 285 36.7 260 -5 315 30.4 261 -5 325 25.4 262 -5 335 20.3 263 -5 345 17.9 264 -5 355 21.0 265 -15 5 15.7 266 -15 15 15.4 268 -15 35 11.3 269 -15 45 16.9 270 -15 55 22.0 271 -15 65 24.3 272 -15 75 36.4 273 -15 85 33.5 274 -15 95 40.1 275 -15 105 33.1 276 -15 115 24.5 277 -15 125 26.0 278 -15 135 34.9 279 -15 145 30.7 280 -15 155 34.5 281 -15 165 37.8 282 -15 175 34.3 283 -15 185 38.6 284 -15 195 33.6 285 -15 205 26.6 286 -15 215 24.9 287 -15 225 20.0 288 -15 235 18.7 289 -15 245 18.9 290 -15 255 19.8 291 -15 265 23.7 292 -15 275 24.3 293 -15 285 29.4 297 -15 325 31.9 298 -15 335 27.5 299 -15 345 24.1 300 -15 355 19.0 301 -25 5 18.5 302 -25 15 16.7 304 -25 35 14.8 305 -25 45 17.1 306 -25 55 18.0 307 -25 65 19.5 308 -25 75 16.4 309 -25 85 17.2 310 -25 95 18.2 311 -25 105 20.8 312 -25 115 18.1 315 -25 145 19.5 316 -25 155 21.9 317 -25 165 26.2 318 -25 175 30.0 319 -25 185 30.1 320 -25 195 32.8 321 -25 205 38.9 322 -25 215 40.1 323 -25 225 40.7 324 -25 235 35.6 325 -25 245 33.7 326 -25 255 36.2 327 -25 265 29.6 328 -25 275 22.6 329 -25 285 27.4 332 -25 315 39.5 333 -25 325 35.0 334 -25 335 33.0 335 -25 345 32.6 336 -25 355 27.9 337 -35 5 34.3 338 -35 15 27.4 339 -35 25 31.2 340 -35 35 24.5 341 -35 45 26.6 342 -35 55 24.8 343 -35 65 25.2 344 -35 75 24.0 345 -35 85 19.0 346 -35 95 22.6 347 -35 105 23.9 348 -35 115 28.3 349 -35 125 33.0 350 -35 135 36.6 351 -35 145 40.4 352 -35 155 32.1 353 -35 165 31.3 354 -35 175 31.3 355 -35 185 31.4 356 -35 195 29.6 357 -35 205 35.0 358 -35 215 34.6 359 -35 225 40.9 360 -35 235 44.5 361 -35 245 38.6 362 -35 255 44.7 363 -35 265 35.9 364 -35 275 23.8 365 -35 285 29.6 366 -35 295 49.0 367 -35 305 41.7 368 -35 315 38.5 369 -35 325 37.6 370 -35 335 35.1 371 -35 345 38.5 372 -35 355 37.3 374 -45 15 32.8 375 -45 25 42.6 376 -45 35 30.1 377 -45 45 30.9 378 -45 55 28.9 379 -45 65 24.1 380 -45 75 36.5 383 -45 105 29.4 384 -45 115 39.8 385 -45 125 41.6 386 -45 135 47.3 387 -45 145 43.3 388 -45 155 40.7 389 -45 165 39.7 390 -45 175 38.0 391 -45 185 32.4 392 -45 195 26.7 393 -45 205 27.0 394 -45 215 27.4 395 -45 225 35.3 396 -45 235 33.1 397 -45 245 32.2 398 -45 255 23.6 399 -45 265 28.4 400 -45 275 22.8 401 -45 285 23.4 402 -45 295 44.2 403 -45 305 34.9 404 -45 315 36.0 405 -45 325 29.1 406 -45 335 25.4 407 -45 345 24.7 408 -45 355 35.2 409 -55 10 22.0 411 -55 50 18.2 412 -55 70 24.7 417 -55 170 34.1 420 -55 230 43.1 421 -55 250 37.2 422 -55 270 32.1 423 -55 290 38.2 424 -55 310 34.4 425 -55 330 23.3