Cumulus Frequency of Occurrence (%) December (1953 - 1996) Night, Ship Observations Only Global Average: 31.0 Zonal Averages 17 zones Lat.N Average 85 0.7 75 5.6 65 12.7 55 16.3 45 18.1 35 28.5 25 39.0 15 46.9 5 42.5 -5 46.3 -15 43.2 -25 38.8 -35 27.8 -45 18.5 -55 10.7 -65 6.5 -75 9.1 Grid Box Averages 365 filled boxes Box # Lat.N Lon.E Average 1 85 60 1.3 2 85 180 0.2 4 75 20 13.7 5 75 60 8.4 8 75 180 0.4 9 75 220 0.8 13 65 10 13.8 14 65 30 11.3 15 65 50 10.9 21 65 170 8.7 22 65 190 9.5 23 65 210 11.9 29 65 330 14.0 30 65 350 14.4 31 55 10 19.7 32 55 30 10.8 38 55 150 12.6 39 55 170 13.7 40 55 190 15.3 41 55 210 15.5 42 55 230 17.2 46 55 310 20.4 47 55 330 17.0 48 55 350 17.8 49 45 5 24.1 50 45 15 22.4 51 45 25 18.5 52 45 35 18.8 54 45 55 17.8 62 45 135 18.3 63 45 145 19.6 64 45 155 16.3 65 45 165 16.0 66 45 175 18.0 67 45 185 19.4 68 45 195 19.2 69 45 205 15.5 70 45 215 15.6 71 45 225 16.3 72 45 235 17.7 77 45 285 19.4 78 45 295 20.3 79 45 305 14.5 80 45 315 17.1 81 45 325 20.7 82 45 335 20.4 83 45 345 19.1 84 45 355 21.1 85 35 5 28.0 86 35 15 33.5 87 35 25 36.5 88 35 35 41.9 97 35 125 24.7 98 35 135 36.9 99 35 145 29.9 100 35 155 27.2 101 35 165 27.6 102 35 175 24.4 103 35 185 22.5 104 35 195 24.6 105 35 205 24.2 106 35 215 23.4 107 35 225 23.4 108 35 235 21.0 109 35 245 19.1 112 35 275 24.9 113 35 285 29.8 114 35 295 31.6 115 35 305 31.5 116 35 315 36.2 117 35 325 31.8 118 35 335 29.2 119 35 345 32.9 120 35 355 25.1 124 25 35 28.0 125 25 45 27.8 126 25 55 22.5 127 25 65 29.6 129 25 85 13.4 132 25 115 27.9 133 25 125 29.4 134 25 135 34.0 135 25 145 39.3 136 25 155 39.4 137 25 165 42.9 138 25 175 39.9 139 25 185 41.0 140 25 195 45.0 141 25 205 43.9 142 25 215 37.0 143 25 225 27.7 144 25 235 26.0 145 25 245 25.7 146 25 255 30.1 147 25 265 31.6 148 25 275 40.6 149 25 285 45.6 150 25 295 50.6 151 25 305 53.5 152 25 315 51.0 153 25 325 49.8 154 25 335 44.8 155 25 345 25.1 160 15 35 36.0 161 15 45 35.7 162 15 55 53.2 163 15 65 52.7 164 15 75 28.4 165 15 85 46.5 166 15 95 47.3 167 15 105 36.1 168 15 115 42.2 169 15 125 37.6 170 15 135 42.9 171 15 145 52.4 172 15 155 57.3 173 15 165 55.4 174 15 175 51.3 175 15 185 50.5 176 15 195 49.9 177 15 205 49.1 178 15 215 42.2 179 15 225 31.6 180 15 235 30.8 181 15 245 42.7 182 15 255 45.5 183 15 265 37.3 184 15 275 45.2 185 15 285 56.0 186 15 295 59.8 187 15 305 63.6 188 15 315 59.6 189 15 325 49.8 190 15 335 38.2 191 15 345 11.5 193 5 5 39.5 197 5 45 58.6 198 5 55 58.7 199 5 65 60.4 200 5 75 43.6 201 5 85 42.7 202 5 95 39.6 203 5 105 36.0 204 5 115 40.1 205 5 125 43.9 206 5 135 46.7 207 5 145 42.7 208 5 155 47.2 209 5 165 49.6 210 5 175 42.8 211 5 185 44.9 212 5 195 46.7 213 5 205 49.2 214 5 215 40.8 215 5 225 41.1 216 5 235 29.2 217 5 245 31.6 218 5 255 33.2 219 5 265 30.3 220 5 275 33.3 221 5 285 36.2 223 5 305 52.2 224 5 315 43.3 225 5 325 48.2 226 5 335 42.1 227 5 345 32.8 228 5 355 37.5 229 -5 5 33.9 230 -5 15 28.1 232 -5 35 51.5 233 -5 45 59.5 234 -5 55 50.1 235 -5 65 48.3 236 -5 75 45.3 237 -5 85 41.3 238 -5 95 45.3 239 -5 105 36.5 240 -5 115 36.7 241 -5 125 40.6 242 -5 135 47.3 243 -5 145 37.4 244 -5 155 42.0 245 -5 165 35.3 246 -5 175 42.4 247 -5 185 50.0 248 -5 195 60.5 249 -5 205 65.8 250 -5 215 68.1 251 -5 225 66.9 252 -5 235 64.8 253 -5 245 47.8 254 -5 255 30.7 255 -5 265 23.4 256 -5 275 22.1 257 -5 285 20.3 260 -5 315 58.5 261 -5 325 68.6 262 -5 335 57.6 263 -5 345 40.3 264 -5 355 29.1 265 -15 5 10.7 266 -15 15 17.0 268 -15 35 48.4 269 -15 45 51.6 270 -15 55 59.0 271 -15 65 57.4 272 -15 75 49.6 273 -15 85 49.6 274 -15 95 45.2 275 -15 105 44.3 276 -15 115 42.5 277 -15 125 45.9 278 -15 135 51.5 279 -15 145 49.9 280 -15 155 56.5 281 -15 165 51.8 282 -15 175 50.6 283 -15 185 44.8 284 -15 195 40.2 285 -15 205 41.0 286 -15 215 50.9 287 -15 225 52.7 288 -15 235 60.2 289 -15 245 58.5 290 -15 255 33.5 291 -15 265 19.7 292 -15 275 18.1 293 -15 285 22.2 297 -15 325 57.1 298 -15 335 51.5 299 -15 345 26.4 300 -15 355 14.2 301 -25 5 19.3 302 -25 15 26.5 304 -25 35 45.6 305 -25 45 46.2 306 -25 55 47.8 307 -25 65 44.0 308 -25 75 45.1 309 -25 85 40.3 310 -25 95 33.2 311 -25 105 32.5 312 -25 115 33.2 316 -25 155 50.5 317 -25 165 48.5 318 -25 175 49.0 319 -25 185 45.2 320 -25 195 39.3 321 -25 205 42.0 322 -25 215 36.9 323 -25 225 41.1 324 -25 235 51.6 325 -25 245 50.8 326 -25 255 31.3 327 -25 265 32.3 328 -25 275 23.6 329 -25 285 18.1 332 -25 315 30.6 333 -25 325 40.8 334 -25 335 42.1 335 -25 345 38.2 336 -25 355 30.1 337 -35 5 26.3 338 -35 15 32.4 339 -35 25 31.2 340 -35 35 31.4 341 -35 45 34.7 342 -35 55 27.7 343 -35 65 24.4 344 -35 75 26.3 345 -35 85 25.0 346 -35 95 19.1 347 -35 105 27.0 348 -35 115 30.6 349 -35 125 23.5 350 -35 135 23.8 351 -35 145 23.1 352 -35 155 27.7 353 -35 165 29.2 354 -35 175 34.2 355 -35 185 34.5 356 -35 195 36.1 357 -35 205 32.3 358 -35 215 26.5 359 -35 225 28.4 360 -35 235 32.1 361 -35 245 18.4 362 -35 255 23.7 363 -35 265 24.9 364 -35 275 25.3 365 -35 285 24.4 367 -35 305 25.3 368 -35 315 33.6 369 -35 325 30.0 370 -35 335 26.6 371 -35 345 24.6 372 -35 355 24.1 373 -45 5 14.0 374 -45 15 22.0 375 -45 25 13.9 376 -45 35 18.3 377 -45 45 12.1 378 -45 55 19.1 379 -45 65 15.5 380 -45 75 12.9 381 -45 85 17.9 382 -45 95 16.9 383 -45 105 19.5 384 -45 115 22.3 385 -45 125 23.6 386 -45 135 27.7 387 -45 145 20.4 388 -45 155 19.9 389 -45 165 20.6 390 -45 175 18.8 391 -45 185 19.9 392 -45 195 23.4 393 -45 205 19.3 394 -45 215 16.8 400 -45 275 20.6 401 -45 285 23.9 402 -45 295 15.1 403 -45 305 21.4 404 -45 315 23.9 405 -45 325 16.4 406 -45 335 12.2 407 -45 345 14.9 408 -45 355 10.4 409 -55 10 9.1 410 -55 30 10.3 411 -55 50 12.3 412 -55 70 9.8 413 -55 90 11.3 414 -55 110 16.9 415 -55 130 10.5 416 -55 150 7.2 417 -55 170 12.9 419 -55 210 8.9 420 -55 230 9.8 421 -55 250 6.6 422 -55 270 13.2 423 -55 290 13.2 424 -55 310 9.7 425 -55 330 9.9 426 -55 350 10.4 427 -65 10 4.1 428 -65 30 8.9 429 -65 50 9.5 430 -65 70 10.2 431 -65 90 8.7 432 -65 110 6.7 433 -65 130 7.2 434 -65 150 6.6 435 -65 170 7.2 436 -65 190 10.3 437 -65 210 6.2 438 -65 230 10.2 439 -65 250 5.3 440 -65 270 2.0 441 -65 290 6.1 442 -65 310 6.2 443 -65 330 1.3 444 -65 350 3.4 449 -75 180 10.6 453 -75 340 6.5