Cumulus Frequency of Occurrence (%) September (1954 - 1997) Night, Ship Observations Only Global Average: 32.8 Zonal Averages 15 zones Lat.N Average 85 1.8 75 4.1 65 10.0 55 14.1 45 18.8 35 37.4 25 48.3 15 44.7 5 43.8 -5 47.9 -15 39.6 -25 34.3 -35 26.1 -45 17.6 -55 13.6 Grid Box Averages 324 filled boxes Box # Lat.N Lon.E Average 1 85 60 3.7 2 85 180 0.4 3 85 300 1.1 4 75 20 8.7 5 75 60 5.5 6 75 100 2.8 7 75 140 2.6 8 75 180 1.8 9 75 220 1.4 10 75 260 3.7 11 75 300 5.7 12 75 340 5.6 13 65 10 14.9 14 65 30 9.5 15 65 50 8.1 16 65 70 8.5 21 65 170 12.7 22 65 190 8.1 23 65 210 12.1 25 65 250 6.2 26 65 270 5.5 27 65 290 4.6 28 65 310 7.9 29 65 330 11.2 30 65 350 13.2 31 55 10 20.6 32 55 30 18.5 38 55 150 12.6 39 55 170 13.0 40 55 190 11.4 41 55 210 14.8 42 55 230 16.7 44 55 270 5.4 45 55 290 9.8 46 55 310 13.4 47 55 330 16.4 48 55 350 16.4 49 45 5 23.9 50 45 15 22.0 51 45 25 16.2 52 45 35 21.4 53 45 45 17.0 54 45 55 12.3 62 45 135 20.3 63 45 145 15.8 64 45 155 13.5 65 45 165 14.0 66 45 175 13.1 67 45 185 13.9 68 45 195 13.6 69 45 205 15.9 70 45 215 17.4 71 45 225 20.2 72 45 235 16.2 77 45 285 13.6 78 45 295 18.7 79 45 305 22.9 80 45 315 22.5 81 45 325 28.2 82 45 335 25.9 83 45 345 23.4 84 45 355 22.4 85 35 5 32.4 86 35 15 28.6 87 35 25 22.4 88 35 35 33.5 97 35 125 29.9 98 35 135 38.5 99 35 145 33.3 100 35 155 34.6 101 35 165 36.3 102 35 175 34.2 103 35 185 33.7 104 35 195 38.2 105 35 205 40.3 106 35 215 35.4 107 35 225 28.0 108 35 235 19.9 109 35 245 14.4 112 35 275 39.8 113 35 285 36.9 114 35 295 46.3 115 35 305 51.0 116 35 315 54.5 117 35 325 51.9 118 35 335 46.2 119 35 345 39.3 120 35 355 23.1 124 25 35 7.7 125 25 45 1.4 126 25 55 10.1 127 25 65 42.3 129 25 85 37.1 132 25 115 39.6 133 25 125 46.4 134 25 135 50.1 135 25 145 49.9 136 25 155 53.0 137 25 165 53.9 138 25 175 55.6 139 25 185 58.1 140 25 195 64.2 141 25 205 59.5 142 25 215 47.1 143 25 225 30.4 144 25 235 22.4 145 25 245 28.3 146 25 255 42.1 147 25 265 48.5 148 25 275 49.5 149 25 285 47.5 150 25 295 54.8 151 25 305 60.4 152 25 315 62.3 153 25 325 57.2 154 25 335 48.6 155 25 345 24.2 160 15 35 17.9 161 15 45 23.5 162 15 55 31.3 163 15 65 55.0 164 15 75 42.0 165 15 85 42.9 166 15 95 34.5 167 15 105 42.4 168 15 115 45.7 169 15 125 40.0 170 15 135 38.1 171 15 145 37.5 172 15 155 44.0 173 15 165 50.2 174 15 175 54.2 175 15 185 57.6 176 15 195 54.8 177 15 205 51.5 178 15 215 41.0 179 15 225 38.0 180 15 235 35.8 181 15 245 41.9 182 15 255 35.2 183 15 265 31.2 184 15 275 42.8 185 15 285 50.2 186 15 295 57.5 187 15 305 56.9 188 15 315 53.5 189 15 325 43.3 190 15 335 43.4 191 15 345 31.5 193 5 5 25.2 197 5 45 52.6 198 5 55 56.9 199 5 65 57.8 200 5 75 47.3 201 5 85 44.9 202 5 95 37.1 203 5 105 40.5 204 5 115 38.7 205 5 125 40.9 206 5 135 46.5 207 5 145 38.7 208 5 155 43.6 209 5 165 58.5 210 5 175 47.0 211 5 185 55.5 212 5 195 52.6 213 5 205 53.6 214 5 215 44.5 215 5 225 53.4 216 5 235 43.3 217 5 245 35.9 218 5 255 27.3 219 5 265 21.5 220 5 275 22.4 221 5 285 27.6 223 5 305 54.9 224 5 315 54.4 225 5 325 55.6 226 5 335 43.5 227 5 345 29.7 228 5 355 22.5 229 -5 5 18.4 230 -5 15 21.6 233 -5 45 60.9 234 -5 55 55.1 235 -5 65 46.0 236 -5 75 42.4 237 -5 85 39.4 238 -5 95 44.8 239 -5 105 48.4 240 -5 115 48.6 241 -5 125 50.0 242 -5 135 57.0 243 -5 145 42.9 244 -5 155 42.0 245 -5 165 53.8 246 -5 175 47.9 247 -5 185 61.9 248 -5 195 66.5 249 -5 205 72.9 250 -5 215 77.2 251 -5 225 74.3 252 -5 235 68.6 253 -5 245 51.0 254 -5 255 23.5 255 -5 265 10.0 256 -5 275 10.7 257 -5 285 9.8 260 -5 315 59.3 261 -5 325 64.2 262 -5 335 54.4 263 -5 345 41.1 264 -5 355 22.1 265 -15 5 6.1 266 -15 15 12.3 268 -15 35 45.7 269 -15 45 49.2 270 -15 55 52.3 271 -15 65 42.5 272 -15 75 34.3 273 -15 85 37.2 274 -15 95 44.2 275 -15 105 51.1 276 -15 115 36.3 277 -15 125 30.5 278 -15 135 51.8 279 -15 145 49.0 280 -15 155 51.7 281 -15 165 46.8 282 -15 175 39.6 283 -15 185 46.3 284 -15 195 51.1 285 -15 205 57.0 286 -15 215 58.4 287 -15 225 65.6 288 -15 235 59.9 289 -15 245 48.4 290 -15 255 31.5 291 -15 265 13.5 292 -15 275 11.2 293 -15 285 9.5 297 -15 325 53.8 298 -15 335 35.6 299 -15 345 22.1 300 -15 355 8.0 301 -25 5 15.2 302 -25 15 19.8 304 -25 35 39.6 305 -25 45 44.9 306 -25 55 50.1 307 -25 65 33.6 308 -25 75 28.4 309 -25 85 24.8 310 -25 95 29.9 311 -25 105 39.1 312 -25 115 34.9 315 -25 145 43.4 316 -25 155 42.4 317 -25 165 48.5 318 -25 175 37.2 319 -25 185 40.4 320 -25 195 37.3 321 -25 205 34.2 322 -25 215 42.0 323 -25 225 43.5 324 -25 235 45.5 325 -25 245 48.7 327 -25 265 22.4 328 -25 275 19.2 329 -25 285 24.8 332 -25 315 23.3 333 -25 325 36.1 334 -25 335 31.0 335 -25 345 31.6 336 -25 355 20.0 337 -35 5 20.9 338 -35 15 25.2 339 -35 25 24.2 340 -35 35 29.7 341 -35 45 26.1 342 -35 55 27.4 343 -35 65 33.1 344 -35 75 24.9 345 -35 85 19.9 346 -35 95 16.3 347 -35 105 24.9 348 -35 115 30.7 349 -35 125 23.2 350 -35 135 22.2 351 -35 145 25.9 352 -35 155 31.9 353 -35 165 33.7 354 -35 175 30.2 355 -35 185 28.2 356 -35 195 31.4 357 -35 205 26.5 358 -35 215 34.7 359 -35 225 36.1 360 -35 235 26.6 363 -35 265 20.0 364 -35 275 21.3 365 -35 285 25.3 367 -35 305 17.3 368 -35 315 22.7 369 -35 325 23.1 370 -35 335 30.0 371 -35 345 24.1 372 -35 355 18.3 387 -45 145 21.9 388 -45 155 25.7 389 -45 165 16.4 390 -45 175 19.6 391 -45 185 18.3 392 -45 195 14.1 400 -45 275 12.8 401 -45 285 25.1 402 -45 295 11.8 403 -45 305 14.3 404 -45 315 14.7 417 -55 170 13.5 422 -55 270 15.9 423 -55 290 13.1 424 -55 310 16.1 425 -55 330 9.6