Cumulus Frequency of Occurrence (%) September (1954 - 1997) , Ship Observations Only Global Average: 33.5 Zonal Averages 16 zones Lat.N Average 85 1.8 75 5.1 65 11.8 55 16.1 45 21.1 35 39.4 25 49.8 15 46.8 5 45.9 -5 50.4 -15 42.9 -25 37.0 -35 27.4 -45 17.2 -55 13.7 -65 12.6 Grid Box Averages 371 filled boxes Box # Lat.N Lon.E Average 1 85 60 3.7 2 85 180 0.3 3 85 300 1.2 4 75 20 9.9 5 75 60 7.7 6 75 100 3.5 7 75 140 3.3 8 75 180 2.3 9 75 220 1.9 10 75 260 4.0 11 75 300 6.7 12 75 340 6.7 13 65 10 15.9 14 65 30 13.5 15 65 50 11.7 16 65 70 10.9 20 65 150 19.6 21 65 170 14.7 22 65 190 10.1 23 65 210 13.8 24 65 230 9.3 25 65 250 7.8 26 65 270 6.6 27 65 290 6.3 28 65 310 9.1 29 65 330 13.3 30 65 350 14.6 31 55 10 22.5 32 55 30 21.9 37 55 130 16.6 38 55 150 15.7 39 55 170 15.5 40 55 190 12.8 41 55 210 16.9 42 55 230 19.3 44 55 270 8.3 45 55 290 13.0 46 55 310 14.6 47 55 330 17.4 48 55 350 18.4 49 45 5 25.6 50 45 15 26.0 51 45 25 21.7 52 45 35 25.4 53 45 45 18.6 54 45 55 14.8 62 45 135 23.8 63 45 145 19.3 64 45 155 16.2 65 45 165 16.4 66 45 175 14.9 67 45 185 15.1 68 45 195 15.4 69 45 205 17.7 70 45 215 18.9 71 45 225 22.5 72 45 235 18.6 77 45 285 16.9 78 45 295 21.2 79 45 305 25.6 80 45 315 24.6 81 45 325 29.7 82 45 335 28.6 83 45 345 26.2 84 45 355 24.8 85 35 5 32.0 86 35 15 34.4 87 35 25 27.6 88 35 35 37.9 90 35 55 22.6 96 35 115 19.7 97 35 125 29.6 98 35 135 40.0 99 35 145 35.3 100 35 155 36.5 101 35 165 38.6 102 35 175 36.4 103 35 185 35.9 104 35 195 39.5 105 35 205 41.0 106 35 215 37.1 107 35 225 30.9 108 35 235 21.7 109 35 245 15.7 112 35 275 41.8 113 35 285 39.0 114 35 295 47.6 115 35 305 51.8 116 35 315 55.7 117 35 325 53.8 118 35 335 48.8 119 35 345 43.6 120 35 355 24.1 124 25 35 8.7 125 25 45 1.8 126 25 55 12.4 127 25 65 43.7 128 25 75 51.0 129 25 85 40.3 130 25 95 44.8 131 25 105 42.9 132 25 115 39.9 133 25 125 47.8 134 25 135 50.6 135 25 145 51.5 136 25 155 54.5 137 25 165 55.5 138 25 175 57.8 139 25 185 58.9 140 25 195 64.3 141 25 205 60.7 142 25 215 49.0 143 25 225 33.2 144 25 235 24.8 145 25 245 30.5 146 25 255 46.2 147 25 265 48.1 148 25 275 48.3 149 25 285 49.9 150 25 295 56.3 151 25 305 61.9 152 25 315 63.0 153 25 325 60.0 154 25 335 52.2 155 25 345 25.0 160 15 35 21.4 161 15 45 27.2 162 15 55 33.0 163 15 65 56.4 164 15 75 45.6 165 15 85 44.2 166 15 95 38.2 167 15 105 44.7 168 15 115 45.6 169 15 125 41.3 170 15 135 39.6 171 15 145 39.9 172 15 155 45.1 173 15 165 52.3 174 15 175 55.1 175 15 185 56.7 176 15 195 57.9 177 15 205 53.8 178 15 215 45.0 179 15 225 41.4 180 15 235 39.6 181 15 245 45.3 182 15 255 39.5 183 15 265 35.3 184 15 275 43.5 185 15 285 52.4 186 15 295 58.2 187 15 305 57.8 188 15 315 54.3 189 15 325 46.7 190 15 335 45.8 191 15 345 33.4 193 5 5 29.0 197 5 45 57.5 198 5 55 58.6 199 5 65 61.2 200 5 75 50.1 201 5 85 47.0 202 5 95 39.2 203 5 105 42.1 204 5 115 40.4 205 5 125 43.9 206 5 135 47.1 207 5 145 42.2 208 5 155 45.8 209 5 165 55.1 210 5 175 49.4 211 5 185 54.6 212 5 195 54.2 213 5 205 54.4 214 5 215 45.7 215 5 225 51.0 216 5 235 46.1 217 5 245 39.9 218 5 255 30.0 219 5 265 23.9 220 5 275 24.7 221 5 285 27.9 223 5 305 58.3 224 5 315 57.6 225 5 325 58.2 226 5 335 46.8 227 5 345 34.3 228 5 355 28.3 229 -5 5 23.8 230 -5 15 19.5 232 -5 35 59.7 233 -5 45 62.9 234 -5 55 57.8 235 -5 65 51.5 236 -5 75 43.8 237 -5 85 41.6 238 -5 95 45.1 239 -5 105 49.6 240 -5 115 55.7 241 -5 125 54.2 242 -5 135 59.2 243 -5 145 45.1 244 -5 155 44.0 245 -5 165 53.6 246 -5 175 52.5 247 -5 185 62.6 248 -5 195 68.3 249 -5 205 71.1 250 -5 215 74.9 251 -5 225 73.2 252 -5 235 70.2 253 -5 245 54.8 254 -5 255 29.2 255 -5 265 15.3 256 -5 275 12.9 257 -5 285 8.2 260 -5 315 64.1 261 -5 325 66.3 262 -5 335 58.6 263 -5 345 44.6 264 -5 355 28.3 265 -15 5 8.4 266 -15 15 12.3 268 -15 35 51.6 269 -15 45 57.4 270 -15 55 56.9 271 -15 65 48.3 272 -15 75 40.4 273 -15 85 41.1 274 -15 95 46.0 275 -15 105 53.5 276 -15 115 38.4 277 -15 125 38.9 278 -15 135 58.3 279 -15 145 53.0 280 -15 155 54.1 281 -15 165 48.0 282 -15 175 42.6 283 -15 185 48.6 284 -15 195 52.9 285 -15 205 59.0 286 -15 215 60.7 287 -15 225 65.3 288 -15 235 64.0 289 -15 245 51.5 290 -15 255 36.3 291 -15 265 19.6 292 -15 275 11.3 293 -15 285 9.6 297 -15 325 55.7 298 -15 335 41.8 299 -15 345 26.6 300 -15 355 10.7 301 -25 5 19.2 302 -25 15 20.9 304 -25 35 42.4 305 -25 45 47.2 306 -25 55 52.6 307 -25 65 40.1 308 -25 75 35.2 309 -25 85 30.8 310 -25 95 35.3 311 -25 105 39.3 312 -25 115 36.2 315 -25 145 44.5 316 -25 155 48.0 317 -25 165 49.9 318 -25 175 42.2 319 -25 185 41.7 320 -25 195 37.9 321 -25 205 37.6 322 -25 215 41.2 323 -25 225 43.7 324 -25 235 47.8 325 -25 245 49.3 326 -25 255 36.5 327 -25 265 23.6 328 -25 275 22.5 329 -25 285 23.8 332 -25 315 25.1 333 -25 325 38.5 334 -25 335 35.8 335 -25 345 33.3 336 -25 355 24.0 337 -35 5 23.0 338 -35 15 27.5 339 -35 25 25.6 340 -35 35 31.0 341 -35 45 28.4 342 -35 55 28.3 343 -35 65 30.7 344 -35 75 25.0 345 -35 85 20.7 346 -35 95 21.0 347 -35 105 25.6 348 -35 115 30.8 349 -35 125 25.3 350 -35 135 24.5 351 -35 145 26.8 352 -35 155 34.3 353 -35 165 34.5 354 -35 175 33.6 355 -35 185 30.9 356 -35 195 31.0 357 -35 205 28.3 358 -35 215 32.1 359 -35 225 33.5 360 -35 235 28.7 361 -35 245 26.5 362 -35 255 27.9 363 -35 265 21.7 364 -35 275 22.5 365 -35 285 26.7 366 -35 295 16.5 367 -35 305 18.7 368 -35 315 25.6 369 -35 325 25.7 370 -35 335 30.2 371 -35 345 26.1 372 -35 355 22.5 373 -45 5 15.6 375 -45 25 26.6 376 -45 35 13.7 377 -45 45 10.1 378 -45 55 18.5 379 -45 65 16.7 380 -45 75 16.2 381 -45 85 8.8 382 -45 95 14.2 383 -45 105 17.8 384 -45 115 23.8 385 -45 125 25.2 386 -45 135 26.1 387 -45 145 25.8 388 -45 155 25.1 389 -45 165 18.5 390 -45 175 21.8 391 -45 185 18.4 392 -45 195 16.1 393 -45 205 12.9 394 -45 215 16.0 395 -45 225 15.5 396 -45 235 13.1 397 -45 245 7.8 399 -45 265 14.9 400 -45 275 14.1 401 -45 285 24.1 402 -45 295 13.1 403 -45 305 14.1 404 -45 315 16.4 405 -45 325 17.1 407 -45 345 12.7 408 -45 355 18.7 409 -55 10 20.1 411 -55 50 15.8 412 -55 70 11.7 414 -55 110 10.6 416 -55 150 19.1 417 -55 170 14.3 419 -55 210 11.2 420 -55 230 10.0 421 -55 250 7.8 422 -55 270 15.5 423 -55 290 14.6 424 -55 310 15.1 425 -55 330 10.8 426 -55 350 15.2 432 -65 110 20.1 433 -65 130 18.9 442 -65 310 3.7