High Level (Cirriform) Amount-When-Present (%) September, October, November (1954 - 1997) Night, Ship Observations Only Global Average: 35.8 Zonal Averages 16 zones Lat.N Average 85 32.2 75 44.1 65 36.6 55 37.3 45 36.8 35 35.3 25 31.3 15 35.4 5 37.0 -5 36.4 -15 32.4 -25 34.8 -35 35.4 -45 37.0 -55 38.6 -75 43.1 Grid Box Averages 282 filled boxes Box # Lat.N Lon.E Average 1 85 60 24.2 2 85 180 44.0 3 85 300 24.6 4 75 20 34.6 5 75 60 36.4 6 75 100 42.0 7 75 140 42.8 8 75 180 53.0 9 75 220 51.2 10 75 260 38.5 11 75 300 40.0 12 75 340 34.9 13 65 10 31.8 14 65 30 37.9 15 65 50 38.7 21 65 170 35.3 22 65 190 37.4 26 65 270 42.7 27 65 290 39.7 28 65 310 36.7 29 65 330 34.8 30 65 350 33.7 31 55 10 34.1 32 55 30 41.1 38 55 150 35.7 39 55 170 32.9 40 55 190 33.2 41 55 210 39.9 42 55 230 35.7 45 55 290 38.9 46 55 310 42.1 47 55 330 44.2 48 55 350 35.4 49 45 5 31.2 50 45 15 34.2 51 45 25 42.2 52 45 35 40.6 62 45 135 36.3 63 45 145 36.9 64 45 155 34.9 65 45 165 32.4 66 45 175 35.0 67 45 185 36.9 68 45 195 39.3 69 45 205 36.9 70 45 215 35.0 71 45 225 38.0 72 45 235 36.4 77 45 285 40.0 78 45 295 39.6 79 45 305 39.5 80 45 315 41.7 81 45 325 38.5 82 45 335 37.6 83 45 345 34.8 84 45 355 32.6 85 35 5 31.5 86 35 15 34.8 87 35 25 37.2 88 35 35 34.2 97 35 125 37.6 98 35 135 36.1 99 35 145 33.8 100 35 155 34.3 101 35 165 40.3 102 35 175 34.3 103 35 185 33.6 104 35 195 33.4 105 35 205 34.7 106 35 215 35.5 107 35 225 36.1 108 35 235 36.3 109 35 245 41.0 112 35 275 35.0 113 35 285 38.0 114 35 295 37.6 115 35 305 33.9 116 35 315 36.4 117 35 325 33.3 118 35 335 35.3 119 35 345 33.1 120 35 355 30.9 124 25 35 37.1 125 25 45 40.0 126 25 55 35.3 127 25 65 35.9 132 25 115 36.0 133 25 125 35.1 134 25 135 29.4 135 25 145 28.9 136 25 155 28.2 137 25 165 31.5 138 25 175 29.2 139 25 185 28.4 140 25 195 32.9 141 25 205 34.1 142 25 215 34.5 143 25 225 34.4 144 25 235 27.0 145 25 245 31.9 146 25 255 36.0 147 25 265 28.2 148 25 275 27.4 149 25 285 32.4 150 25 295 30.7 151 25 305 32.0 152 25 315 31.4 153 25 325 32.7 154 25 335 35.0 155 25 345 37.1 160 15 35 35.4 161 15 45 33.0 162 15 55 32.0 163 15 65 30.9 164 15 75 38.2 165 15 85 32.2 166 15 95 32.7 167 15 105 44.5 168 15 115 39.6 169 15 125 35.2 170 15 135 35.0 171 15 145 31.7 172 15 155 36.4 173 15 165 40.9 174 15 175 36.5 175 15 185 35.8 176 15 195 40.0 177 15 205 37.3 178 15 215 30.4 179 15 225 38.1 180 15 235 35.0 181 15 245 35.3 182 15 255 31.7 183 15 265 30.7 184 15 275 31.3 185 15 285 35.2 186 15 295 31.7 187 15 305 32.1 188 15 315 35.8 189 15 325 38.4 190 15 335 46.4 191 15 345 43.9 193 5 5 40.4 197 5 45 29.3 198 5 55 31.8 199 5 65 34.4 200 5 75 37.4 201 5 85 36.3 202 5 95 42.3 203 5 105 45.1 204 5 115 42.2 205 5 125 42.8 206 5 135 37.7 207 5 145 36.1 208 5 155 38.0 209 5 165 44.0 210 5 175 32.9 211 5 185 30.4 212 5 195 40.6 213 5 205 36.8 214 5 215 30.2 219 5 265 33.0 220 5 275 35.0 221 5 285 49.0 223 5 305 29.8 224 5 315 31.2 225 5 325 31.3 226 5 335 36.7 227 5 345 37.7 228 5 355 33.8 229 -5 5 37.4 230 -5 15 29.1 233 -5 45 25.8 234 -5 55 32.8 235 -5 65 39.7 236 -5 75 35.9 237 -5 85 36.0 238 -5 95 40.6 239 -5 105 49.1 240 -5 115 43.0 241 -5 125 40.7 242 -5 135 38.9 243 -5 145 44.4 244 -5 155 38.6 245 -5 165 32.8 246 -5 175 27.4 247 -5 185 30.4 248 -5 195 35.0 249 -5 205 33.2 255 -5 265 35.3 256 -5 275 43.6 260 -5 315 27.3 261 -5 325 26.7 262 -5 335 28.3 263 -5 345 25.5 264 -5 355 31.2 265 -15 5 38.4 266 -15 15 33.4 269 -15 45 29.7 270 -15 55 27.4 271 -15 65 32.3 272 -15 75 33.9 273 -15 85 31.5 274 -15 95 30.6 275 -15 105 30.5 276 -15 115 27.3 277 -15 125 30.9 278 -15 135 37.1 279 -15 145 32.6 280 -15 155 35.5 281 -15 165 30.7 282 -15 175 32.7 283 -15 185 30.4 284 -15 195 34.3 285 -15 205 33.5 286 -15 215 24.8 287 -15 225 23.1 293 -15 285 35.3 297 -15 325 31.9 299 -15 345 37.5 300 -15 355 44.4 301 -25 5 33.8 302 -25 15 30.7 304 -25 35 34.4 305 -25 45 31.0 306 -25 55 26.9 308 -25 75 33.4 310 -25 95 32.0 311 -25 105 29.3 312 -25 115 28.8 316 -25 155 32.1 317 -25 165 30.4 318 -25 175 32.2 319 -25 185 32.8 320 -25 195 40.9 321 -25 205 47.4 322 -25 215 40.5 323 -25 225 39.6 324 -25 235 34.4 329 -25 285 29.4 332 -25 315 42.3 333 -25 325 35.8 334 -25 335 30.7 335 -25 345 32.5 336 -25 355 33.3 337 -35 5 33.1 338 -35 15 31.9 339 -35 25 34.0 340 -35 35 37.4 341 -35 45 36.4 342 -35 55 32.7 344 -35 75 33.4 345 -35 85 36.0 346 -35 95 32.8 347 -35 105 37.4 348 -35 115 36.4 349 -35 125 42.9 350 -35 135 42.7 351 -35 145 37.5 352 -35 155 36.5 353 -35 165 36.5 354 -35 175 28.1 355 -35 185 33.5 356 -35 195 31.7 364 -35 275 36.0 365 -35 285 41.9 367 -35 305 39.7 368 -35 315 36.9 371 -35 345 39.3 372 -35 355 34.8 387 -45 145 42.8 388 -45 155 39.3 389 -45 165 38.3 390 -45 175 31.5 391 -45 185 36.0 402 -45 295 37.9 403 -45 305 34.3 417 -55 170 41.5 423 -55 290 34.9 424 -55 310 37.9 425 -55 330 42.7 449 -75 180 43.1