Cumulus Frequency of Occurrence (%) December, January, February (1954 - 1997) , Ship Observations Only Global Average: 33.4 Zonal Averages 17 zones Lat.N Average 85 1.4 75 5.2 65 12.2 55 15.2 45 17.5 35 28.0 25 39.7 15 49.1 5 45.9 -5 51.2 -15 47.5 -25 44.8 -35 31.8 -45 18.8 -55 12.7 -65 7.8 -75 7.8 Grid Box Averages 394 filled boxes Box # Lat.N Lon.E Average 1 85 60 3.0 2 85 180 0.3 3 85 300 0.8 4 75 20 11.6 5 75 60 6.1 6 75 100 5.4 7 75 140 2.1 8 75 180 0.5 9 75 220 0.4 11 75 300 9.1 12 75 340 12.4 13 65 10 12.9 14 65 30 11.1 15 65 50 10.1 21 65 170 8.8 22 65 190 7.1 23 65 210 8.6 27 65 290 13.2 29 65 330 12.9 30 65 350 15.2 31 55 10 15.9 32 55 30 11.5 37 55 130 21.8 38 55 150 13.3 39 55 170 13.1 40 55 190 13.5 41 55 210 13.2 42 55 230 14.2 45 55 290 22.5 46 55 310 19.6 47 55 330 16.6 48 55 350 15.5 49 45 5 25.0 50 45 15 22.5 51 45 25 15.5 52 45 35 15.4 53 45 45 11.8 54 45 55 15.2 61 45 125 24.2 62 45 135 20.1 63 45 145 21.7 64 45 155 15.9 65 45 165 15.7 66 45 175 16.6 67 45 185 17.8 68 45 195 17.1 69 45 205 15.1 70 45 215 14.8 71 45 225 15.2 72 45 235 16.0 77 45 285 18.5 78 45 295 18.8 79 45 305 14.6 80 45 315 17.2 81 45 325 19.9 82 45 335 20.3 83 45 345 19.6 84 45 355 20.4 85 35 5 29.2 86 35 15 33.7 87 35 25 36.2 88 35 35 39.4 89 35 45 22.7 90 35 55 20.0 96 35 115 10.2 97 35 125 22.9 98 35 135 35.5 99 35 145 29.7 100 35 155 25.6 101 35 165 28.9 102 35 175 25.5 103 35 185 24.6 104 35 195 24.0 105 35 205 23.1 106 35 215 22.3 107 35 225 23.1 108 35 235 21.7 109 35 245 19.7 112 35 275 24.1 113 35 285 27.8 114 35 295 28.3 115 35 305 30.6 116 35 315 34.5 117 35 325 31.5 118 35 335 29.8 119 35 345 32.2 120 35 355 26.8 124 25 35 32.3 125 25 45 19.9 126 25 55 26.6 127 25 65 31.8 128 25 75 12.0 129 25 85 19.9 130 25 95 18.7 131 25 105 14.3 132 25 115 21.9 133 25 125 28.5 134 25 135 37.0 135 25 145 42.9 136 25 155 41.9 137 25 165 42.3 138 25 175 41.6 139 25 185 42.8 140 25 195 44.4 141 25 205 44.4 142 25 215 37.1 143 25 225 29.6 144 25 235 28.0 145 25 245 27.3 146 25 255 32.6 147 25 265 28.8 148 25 275 41.4 149 25 285 46.7 150 25 295 51.9 151 25 305 53.5 152 25 315 50.2 153 25 325 48.4 154 25 335 45.6 155 25 345 26.1 156 25 355 33.8 160 15 35 39.2 161 15 45 40.6 162 15 55 55.1 163 15 65 53.2 164 15 75 34.8 165 15 85 49.4 166 15 95 40.4 167 15 105 33.7 168 15 115 47.6 169 15 125 42.4 170 15 135 48.0 171 15 145 53.1 172 15 155 58.2 173 15 165 59.0 174 15 175 55.6 175 15 185 53.3 176 15 195 54.9 177 15 205 52.0 178 15 215 44.5 179 15 225 38.7 180 15 235 34.7 181 15 245 45.2 182 15 255 47.0 183 15 265 38.8 184 15 275 45.8 185 15 285 57.7 186 15 295 62.3 187 15 305 62.4 188 15 315 58.7 189 15 325 51.1 190 15 335 38.6 191 15 345 10.2 193 5 5 41.6 197 5 45 65.9 198 5 55 64.3 199 5 65 65.9 200 5 75 49.7 201 5 85 50.4 202 5 95 47.3 203 5 105 43.5 204 5 115 44.0 205 5 125 43.9 206 5 135 47.4 207 5 145 43.8 208 5 155 47.0 209 5 165 49.6 210 5 175 47.5 211 5 185 47.5 212 5 195 51.5 213 5 205 46.8 214 5 215 41.4 215 5 225 39.2 216 5 235 36.8 217 5 245 41.7 218 5 255 44.4 219 5 265 41.4 220 5 275 39.7 221 5 285 34.3 222 5 295 55.6 223 5 305 53.1 224 5 315 42.2 225 5 325 45.5 226 5 335 42.5 227 5 345 31.9 228 5 355 41.2 229 -5 5 43.6 230 -5 15 33.8 232 -5 35 54.4 233 -5 45 63.6 234 -5 55 55.9 235 -5 65 50.7 236 -5 75 46.6 237 -5 85 45.7 238 -5 95 41.8 239 -5 105 38.8 240 -5 115 36.4 241 -5 125 43.3 242 -5 135 43.2 243 -5 145 39.1 244 -5 155 41.8 245 -5 165 42.8 246 -5 175 44.2 247 -5 185 53.1 248 -5 195 59.5 249 -5 205 68.0 250 -5 215 68.5 251 -5 225 69.2 252 -5 235 69.8 253 -5 245 58.9 254 -5 255 46.0 255 -5 265 40.7 256 -5 275 30.4 257 -5 285 22.9 260 -5 315 49.2 261 -5 325 63.8 262 -5 335 59.9 263 -5 345 55.0 264 -5 355 50.3 265 -15 5 25.3 266 -15 15 18.7 268 -15 35 50.5 269 -15 45 48.7 270 -15 55 54.2 271 -15 65 53.8 272 -15 75 48.4 273 -15 85 52.1 274 -15 95 48.3 275 -15 105 47.0 276 -15 115 43.8 277 -15 125 45.6 278 -15 135 46.1 279 -15 145 44.1 280 -15 155 51.0 281 -15 165 48.3 282 -15 175 46.6 283 -15 185 44.1 284 -15 195 42.6 285 -15 205 47.0 286 -15 215 53.4 287 -15 225 61.5 288 -15 235 63.9 289 -15 245 61.0 290 -15 255 48.1 291 -15 265 39.0 292 -15 275 34.6 293 -15 285 27.7 297 -15 325 60.4 298 -15 335 57.7 299 -15 345 43.7 300 -15 355 33.1 301 -25 5 29.3 302 -25 15 25.8 304 -25 35 50.9 305 -25 45 50.7 306 -25 55 53.1 307 -25 65 51.3 308 -25 75 52.8 309 -25 85 47.2 310 -25 95 38.1 311 -25 105 32.6 312 -25 115 31.8 315 -25 145 48.3 316 -25 155 51.1 317 -25 165 50.7 318 -25 175 47.5 319 -25 185 45.9 320 -25 195 43.3 321 -25 205 41.8 322 -25 215 44.8 323 -25 225 51.6 324 -25 235 56.7 325 -25 245 56.8 326 -25 255 48.3 327 -25 265 42.3 328 -25 275 32.1 329 -25 285 21.6 332 -25 315 37.2 333 -25 325 49.5 334 -25 335 51.5 335 -25 345 50.3 336 -25 355 40.5 337 -35 5 32.7 338 -35 15 33.1 339 -35 25 32.1 340 -35 35 36.3 341 -35 45 37.2 342 -35 55 31.9 343 -35 65 30.0 344 -35 75 30.3 345 -35 85 29.4 346 -35 95 25.6 347 -35 105 27.0 348 -35 115 30.7 349 -35 125 25.4 350 -35 135 26.3 351 -35 145 27.2 352 -35 155 35.1 353 -35 165 35.0 354 -35 175 36.9 355 -35 185 39.1 356 -35 195 34.6 357 -35 205 32.5 358 -35 215 29.2 359 -35 225 29.9 360 -35 235 35.0 361 -35 245 32.3 362 -35 255 31.2 363 -35 265 27.6 364 -35 275 28.2 365 -35 285 26.1 366 -35 295 18.2 367 -35 305 31.2 368 -35 315 38.7 369 -35 325 32.0 370 -35 335 30.9 371 -35 345 32.3 372 -35 355 32.2 373 -45 5 15.2 374 -45 15 17.5 375 -45 25 17.6 376 -45 35 15.4 377 -45 45 15.2 378 -45 55 18.4 379 -45 65 17.7 380 -45 75 17.7 381 -45 85 18.9 382 -45 95 18.8 383 -45 105 18.3 384 -45 115 21.4 385 -45 125 20.0 386 -45 135 21.2 387 -45 145 23.3 388 -45 155 23.2 389 -45 165 21.8 390 -45 175 23.1 391 -45 185 23.1 392 -45 195 22.5 393 -45 205 19.8 394 -45 215 16.0 395 -45 225 17.3 396 -45 235 15.8 397 -45 245 11.7 398 -45 255 15.7 399 -45 265 19.9 400 -45 275 24.5 401 -45 285 22.0 402 -45 295 19.1 403 -45 305 20.4 404 -45 315 24.7 405 -45 325 18.8 406 -45 335 14.4 407 -45 345 17.3 408 -45 355 13.2 409 -55 10 10.5 410 -55 30 11.9 411 -55 50 12.6 412 -55 70 12.9 413 -55 90 12.3 414 -55 110 15.0 415 -55 130 13.5 416 -55 150 10.5 417 -55 170 15.2 418 -55 190 11.1 419 -55 210 11.7 420 -55 230 10.0 421 -55 250 12.4 422 -55 270 15.9 423 -55 290 16.8 424 -55 310 13.4 425 -55 330 11.0 426 -55 350 12.9 427 -65 10 9.9 428 -65 30 7.6 429 -65 50 9.1 430 -65 70 12.3 431 -65 90 8.2 432 -65 110 6.6 433 -65 130 6.2 434 -65 150 6.7 435 -65 170 8.0 436 -65 190 8.2 437 -65 210 7.2 438 -65 230 8.7 439 -65 250 10.0 440 -65 270 7.5 441 -65 290 6.7 442 -65 310 6.4 443 -65 330 5.0 444 -65 350 6.5 449 -75 180 13.4 450 -75 220 3.5 451 -75 260 3.5 452 -75 300 8.8 453 -75 340 7.2