Nimbostratus Amount-When-Present (%) September, October, November (1954 - 1997) Night, Ship Observations Only Global Average: 98.8 Zonal Averages 17 zones Lat.N Average 85 98.4 75 99.1 65 99.3 55 99.3 45 99.4 35 99.0 25 98.1 15 98.3 5 98.4 -5 98.7 -15 98.3 -25 99.0 -35 98.9 -45 99.3 -55 99.4 -65 98.6 -75 97.9 Grid Box Averages 214 filled boxes Box # Lat.N Lon.E Average 1 85 60 98.8 2 85 180 97.7 3 85 300 99.1 4 75 20 99.2 5 75 60 99.0 6 75 100 99.5 7 75 140 99.5 8 75 180 98.6 9 75 220 99.0 10 75 260 99.0 11 75 300 98.4 12 75 340 99.7 13 65 10 99.2 14 65 30 98.4 15 65 50 99.3 21 65 170 99.8 22 65 190 99.7 26 65 270 99.3 27 65 290 99.2 28 65 310 99.1 29 65 330 99.3 30 65 350 99.3 31 55 10 98.9 32 55 30 99.5 38 55 150 99.4 39 55 170 99.4 40 55 190 99.4 41 55 210 99.3 42 55 230 99.1 45 55 290 99.9 46 55 310 99.4 47 55 330 99.3 48 55 350 99.0 49 45 5 98.2 50 45 15 98.0 62 45 135 99.7 63 45 145 99.5 64 45 155 99.5 65 45 165 99.7 66 45 175 99.4 67 45 185 99.4 68 45 195 99.4 69 45 205 99.3 70 45 215 99.4 71 45 225 99.4 72 45 235 99.3 77 45 285 99.6 78 45 295 99.7 79 45 305 99.5 80 45 315 99.4 81 45 325 99.1 82 45 335 99.0 83 45 345 99.0 84 45 355 98.5 85 35 5 97.2 86 35 15 97.7 87 35 25 98.5 97 35 125 99.3 98 35 135 99.3 99 35 145 99.4 100 35 155 99.4 101 35 165 99.2 102 35 175 99.1 103 35 185 99.2 104 35 195 99.3 105 35 205 99.1 106 35 215 98.7 107 35 225 98.7 108 35 235 98.7 109 35 245 99.4 113 35 285 98.8 114 35 295 98.9 115 35 305 98.6 116 35 315 98.2 117 35 325 98.7 118 35 335 98.9 119 35 345 98.0 120 35 355 97.8 132 25 115 98.8 133 25 125 99.0 134 25 135 98.8 135 25 145 98.9 136 25 155 99.6 137 25 165 97.2 138 25 175 98.1 139 25 185 98.0 140 25 195 96.4 141 25 205 96.9 142 25 215 96.1 143 25 225 98.1 147 25 265 97.2 148 25 275 97.5 149 25 285 97.9 150 25 295 98.2 151 25 305 98.4 152 25 315 98.3 153 25 325 96.9 155 25 345 98.5 164 15 75 98.0 165 15 85 97.5 166 15 95 97.1 167 15 105 99.0 168 15 115 98.9 169 15 125 98.9 170 15 135 98.5 171 15 145 97.8 172 15 155 97.4 174 15 175 98.8 179 15 225 98.2 180 15 235 99.0 181 15 245 98.7 182 15 255 98.8 183 15 265 99.0 184 15 275 98.4 185 15 285 96.8 186 15 295 96.7 187 15 305 97.6 188 15 315 98.4 190 15 335 98.3 191 15 345 98.5 193 5 5 97.6 199 5 65 97.5 200 5 75 97.8 201 5 85 98.0 202 5 95 98.4 203 5 105 98.8 204 5 115 98.7 205 5 125 98.4 207 5 145 99.0 208 5 155 98.1 218 5 255 99.0 219 5 265 98.6 220 5 275 98.6 224 5 315 96.5 225 5 325 99.1 226 5 335 99.1 227 5 345 98.4 228 5 355 97.9 229 -5 5 99.2 236 -5 75 98.2 237 -5 85 99.3 238 -5 95 99.0 244 -5 155 98.3 255 -5 265 97.0 256 -5 275 99.3 264 -5 355 98.2 265 -15 5 99.0 273 -15 85 97.7 274 -15 95 98.5 280 -15 155 98.3 281 -15 165 98.3 282 -15 175 98.7 283 -15 185 98.3 297 -15 325 98.1 300 -15 355 97.5 301 -25 5 96.3 304 -25 35 99.5 305 -25 45 99.3 310 -25 95 97.8 316 -25 155 99.1 317 -25 165 98.3 318 -25 175 99.1 319 -25 185 99.5 320 -25 195 99.5 322 -25 215 99.3 323 -25 225 98.9 332 -25 315 99.3 333 -25 325 98.3 337 -35 5 98.3 338 -35 15 97.7 339 -35 25 98.2 340 -35 35 99.0 341 -35 45 98.6 343 -35 65 99.4 344 -35 75 99.5 345 -35 85 98.3 346 -35 95 98.6 348 -35 115 98.0 349 -35 125 98.1 350 -35 135 97.9 351 -35 145 98.1 352 -35 155 98.6 353 -35 165 98.8 354 -35 175 99.0 355 -35 185 98.6 356 -35 195 99.0 357 -35 205 99.5 364 -35 275 99.6 367 -35 305 99.5 368 -35 315 99.2 371 -35 345 99.7 372 -35 355 98.6 379 -45 65 100.0 380 -45 75 99.5 388 -45 155 98.9 389 -45 165 99.2 390 -45 175 99.2 391 -45 185 98.0 392 -45 195 99.5 411 -55 50 99.3 413 -55 90 99.8 416 -55 150 99.1 417 -55 170 99.5 423 -55 290 99.9 424 -55 310 98.9 425 -55 330 99.3 429 -65 50 94.8 430 -65 70 98.3 432 -65 110 99.7 433 -65 130 100.0 435 -65 170 99.4 441 -65 290 99.1 442 -65 310 99.5 449 -75 180 97.9