Cumulus Frequency of Occurrence (%) September, October, November (1954 - 1997) Night, Ship Observations Only Global Average: 31.0 Zonal Averages 17 zones Lat.N Average 85 1.9 75 4.5 65 10.2 55 15.4 45 19.3 35 33.8 25 45.6 15 46.7 5 43.2 -5 48.0 -15 41.2 -25 34.9 -35 25.3 -45 15.9 -55 11.4 -65 5.7 -75 9.1 Grid Box Averages 384 filled boxes Box # Lat.N Lon.E Average 1 85 60 3.9 2 85 180 0.6 3 85 300 1.0 4 75 20 9.8 5 75 60 6.6 6 75 100 2.6 7 75 140 3.0 8 75 180 1.5 9 75 220 1.1 10 75 260 3.9 11 75 300 6.1 12 75 340 6.3 13 65 10 14.5 14 65 30 8.8 15 65 50 9.0 16 65 70 9.6 20 65 150 4.5 21 65 170 11.3 22 65 190 8.3 23 65 210 9.4 25 65 250 6.0 26 65 270 5.1 27 65 290 5.3 28 65 310 8.5 29 65 330 12.0 30 65 350 13.4 31 55 10 19.6 32 55 30 19.7 38 55 150 14.1 39 55 170 14.9 40 55 190 13.6 41 55 210 18.0 42 55 230 18.7 44 55 270 6.7 45 55 290 9.0 46 55 310 13.8 47 55 330 16.8 48 55 350 17.0 49 45 5 25.3 50 45 15 22.7 51 45 25 16.4 52 45 35 20.6 53 45 45 15.5 54 45 55 14.3 62 45 135 19.0 63 45 145 20.1 64 45 155 17.0 65 45 165 15.5 66 45 175 15.1 67 45 185 15.7 68 45 195 16.9 69 45 205 18.1 70 45 215 18.7 71 45 225 20.3 72 45 235 16.6 77 45 285 16.5 78 45 295 18.6 79 45 305 19.5 80 45 315 20.8 81 45 325 24.4 82 45 335 23.7 83 45 345 22.4 84 45 355 21.8 85 35 5 31.6 86 35 15 33.1 87 35 25 29.4 88 35 35 35.9 90 35 55 15.8 96 35 115 16.2 97 35 125 29.1 98 35 135 39.2 99 35 145 32.4 100 35 155 30.0 101 35 165 32.3 102 35 175 29.3 103 35 185 27.3 104 35 195 30.5 105 35 205 31.5 106 35 215 31.4 107 35 225 28.5 108 35 235 20.9 109 35 245 16.2 112 35 275 35.6 113 35 285 35.0 114 35 295 41.3 115 35 305 44.2 116 35 315 46.8 117 35 325 43.4 118 35 335 38.4 119 35 345 38.3 120 35 355 24.3 124 25 35 13.7 125 25 45 5.2 126 25 55 10.3 127 25 65 27.2 128 25 75 23.1 129 25 85 31.9 130 25 95 31.9 131 25 105 41.1 132 25 115 33.1 133 25 125 39.9 134 25 135 45.4 135 25 145 49.6 136 25 155 49.7 137 25 165 51.5 138 25 175 49.4 139 25 185 49.8 140 25 195 55.4 141 25 205 55.5 142 25 215 46.5 143 25 225 32.1 144 25 235 26.0 145 25 245 29.0 146 25 255 41.8 147 25 265 45.0 148 25 275 48.5 149 25 285 48.3 150 25 295 53.5 151 25 305 56.9 152 25 315 56.7 153 25 325 55.5 154 25 335 50.6 155 25 345 25.9 160 15 35 22.7 161 15 45 28.1 162 15 55 41.4 163 15 65 53.6 164 15 75 38.4 165 15 85 44.8 166 15 95 44.6 167 15 105 45.3 168 15 115 44.4 169 15 125 39.4 170 15 135 43.6 171 15 145 44.7 172 15 155 48.5 173 15 165 50.9 174 15 175 51.5 175 15 185 54.3 176 15 195 54.3 177 15 205 51.1 178 15 215 42.9 179 15 225 39.0 180 15 235 34.0 181 15 245 46.0 182 15 255 45.1 183 15 265 35.9 184 15 275 43.2 185 15 285 52.3 186 15 295 57.4 187 15 305 57.8 188 15 315 53.9 189 15 325 52.3 190 15 335 45.8 191 15 345 23.7 193 5 5 33.4 197 5 45 59.5 198 5 55 58.4 199 5 65 59.4 200 5 75 44.9 201 5 85 42.4 202 5 95 36.4 203 5 105 40.1 204 5 115 39.2 205 5 125 41.8 206 5 135 45.9 207 5 145 39.9 208 5 155 43.9 209 5 165 51.6 210 5 175 46.4 211 5 185 52.9 212 5 195 52.4 213 5 205 51.5 214 5 215 43.3 215 5 225 44.6 216 5 235 36.7 217 5 245 34.6 218 5 255 26.2 219 5 265 22.5 220 5 275 23.5 221 5 285 28.3 223 5 305 56.0 224 5 315 55.2 225 5 325 53.8 226 5 335 42.1 227 5 345 34.6 228 5 355 32.3 229 -5 5 21.5 230 -5 15 27.0 232 -5 35 67.8 233 -5 45 63.0 234 -5 55 55.8 235 -5 65 50.1 236 -5 75 43.7 237 -5 85 40.0 238 -5 95 42.7 239 -5 105 43.9 240 -5 115 47.4 241 -5 125 50.4 242 -5 135 53.9 243 -5 145 46.5 244 -5 155 42.0 245 -5 165 48.0 246 -5 175 51.0 247 -5 185 60.4 248 -5 195 66.8 249 -5 205 70.2 250 -5 215 71.8 251 -5 225 72.3 252 -5 235 70.0 253 -5 245 53.1 254 -5 255 26.6 255 -5 265 13.9 256 -5 275 12.0 257 -5 285 10.6 260 -5 315 61.1 261 -5 325 66.2 262 -5 335 56.9 263 -5 345 34.5 264 -5 355 20.6 265 -15 5 6.8 266 -15 15 19.0 268 -15 35 45.3 269 -15 45 52.3 270 -15 55 57.5 271 -15 65 50.6 272 -15 75 43.6 273 -15 85 40.2 274 -15 95 44.2 275 -15 105 51.8 276 -15 115 39.7 277 -15 125 34.9 278 -15 135 50.4 279 -15 145 51.8 280 -15 155 54.6 281 -15 165 45.3 282 -15 175 42.9 283 -15 185 47.0 284 -15 195 47.4 285 -15 205 53.0 286 -15 215 54.8 287 -15 225 64.6 288 -15 235 62.3 289 -15 245 51.8 290 -15 255 30.8 291 -15 265 17.3 292 -15 275 10.1 293 -15 285 12.3 297 -15 325 54.9 298 -15 335 41.5 299 -15 345 20.2 300 -15 355 7.7 301 -25 5 15.5 302 -25 15 22.5 304 -25 35 40.0 305 -25 45 43.5 306 -25 55 51.4 307 -25 65 41.1 308 -25 75 33.4 309 -25 85 29.7 310 -25 95 30.5 311 -25 105 36.3 312 -25 115 34.3 315 -25 145 50.9 316 -25 155 46.1 317 -25 165 43.8 318 -25 175 38.9 319 -25 185 41.2 320 -25 195 36.6 321 -25 205 35.2 322 -25 215 38.6 323 -25 225 40.6 324 -25 235 47.5 325 -25 245 51.0 326 -25 255 34.6 327 -25 265 26.9 328 -25 275 20.4 329 -25 285 21.1 332 -25 315 26.0 333 -25 325 36.4 334 -25 335 32.1 335 -25 345 27.5 336 -25 355 20.7 337 -35 5 20.7 338 -35 15 27.7 339 -35 25 25.2 340 -35 35 27.9 341 -35 45 26.4 342 -35 55 28.7 343 -35 65 26.0 344 -35 75 19.1 345 -35 85 17.8 346 -35 95 18.6 347 -35 105 23.3 348 -35 115 30.1 349 -35 125 23.0 350 -35 135 22.7 351 -35 145 24.4 352 -35 155 29.8 353 -35 165 28.0 354 -35 175 29.4 355 -35 185 29.4 356 -35 195 29.4 357 -35 205 26.8 358 -35 215 28.7 359 -35 225 30.8 360 -35 235 28.1 361 -35 245 28.3 362 -35 255 24.0 363 -35 265 20.1 364 -35 275 23.4 365 -35 285 26.1 367 -35 305 20.1 368 -35 315 29.1 369 -35 325 27.0 370 -35 335 23.8 371 -35 345 21.6 372 -35 355 18.3 373 -45 5 11.3 374 -45 15 14.4 376 -45 35 14.3 377 -45 45 17.3 378 -45 55 13.7 379 -45 65 13.4 380 -45 75 13.7 381 -45 85 12.1 382 -45 95 14.7 383 -45 105 18.8 384 -45 115 22.3 385 -45 125 24.8 386 -45 135 21.7 387 -45 145 22.1 388 -45 155 20.3 389 -45 165 16.6 390 -45 175 19.4 391 -45 185 18.1 392 -45 195 15.5 393 -45 205 13.8 394 -45 215 15.1 396 -45 235 16.5 397 -45 245 12.1 398 -45 255 6.5 399 -45 265 19.7 400 -45 275 18.2 401 -45 285 22.2 402 -45 295 15.9 403 -45 305 14.9 404 -45 315 15.4 405 -45 325 17.3 406 -45 335 10.9 407 -45 345 8.9 408 -45 355 12.1 409 -55 10 8.5 410 -55 30 9.1 411 -55 50 10.1 412 -55 70 13.8 413 -55 90 11.4 414 -55 110 14.8 415 -55 130 12.5 416 -55 150 9.3 417 -55 170 11.6 418 -55 190 19.6 419 -55 210 16.9 420 -55 230 7.8 421 -55 250 6.2 422 -55 270 16.3 423 -55 290 12.0 424 -55 310 10.9 425 -55 330 9.7 426 -55 350 5.3 429 -65 50 5.1 430 -65 70 5.0 431 -65 90 1.3 432 -65 110 11.3 433 -65 130 10.2 434 -65 150 8.6 435 -65 170 5.1 436 -65 190 6.5 441 -65 290 4.4 442 -65 310 6.7 443 -65 330 2.4 444 -65 350 4.1 449 -75 180 8.9 453 -75 340 9.5