Cumulonimbus Amount-When-Present (%) December, January, February (1954 - 1997) , Ship Observations Only Global Average: 58.2 Zonal Averages 16 zones Lat.N Average 75 83.7 65 74.0 55 70.5 45 67.2 35 62.2 25 54.7 15 50.7 5 54.1 -5 51.4 -15 50.5 -25 50.7 -35 56.3 -45 62.9 -55 66.2 -65 73.4 -75 64.8 Grid Box Averages 365 filled boxes Box # Lat.N Lon.E Average 4 75 20 82.4 5 75 60 86.7 12 75 340 82.1 13 65 10 70.8 14 65 30 88.8 15 65 50 82.1 21 65 170 79.7 22 65 190 81.2 23 65 210 80.0 29 65 330 70.8 30 65 350 76.0 31 55 10 67.1 32 55 30 79.1 38 55 150 79.6 39 55 170 69.7 40 55 190 69.4 41 55 210 66.8 42 55 230 67.9 46 55 310 82.7 47 55 330 68.9 48 55 350 64.2 49 45 5 60.6 50 45 15 64.0 51 45 25 82.3 52 45 35 83.7 53 45 45 67.5 54 45 55 69.5 62 45 135 81.5 63 45 145 77.1 64 45 155 72.0 65 45 165 64.7 66 45 175 62.3 67 45 185 62.1 68 45 195 59.9 69 45 205 62.4 70 45 215 62.2 71 45 225 63.1 72 45 235 63.6 77 45 285 79.3 78 45 295 78.6 79 45 305 79.3 80 45 315 75.9 81 45 325 67.8 82 45 335 63.3 83 45 345 62.9 84 45 355 65.4 85 35 5 60.8 86 35 15 60.8 87 35 25 60.7 88 35 35 58.6 90 35 55 65.1 97 35 125 78.1 98 35 135 73.3 99 35 145 67.6 100 35 155 63.7 101 35 165 62.1 102 35 175 60.6 103 35 185 58.5 104 35 195 59.2 105 35 205 59.0 106 35 215 59.9 107 35 225 60.5 108 35 235 59.3 109 35 245 56.8 112 35 275 59.2 113 35 285 64.6 114 35 295 69.2 115 35 305 63.4 116 35 315 60.7 117 35 325 59.6 118 35 335 61.0 119 35 345 60.5 120 35 355 58.4 124 25 35 48.4 125 25 45 63.8 126 25 55 48.7 127 25 65 48.0 132 25 115 67.8 133 25 125 67.5 134 25 135 58.0 135 25 145 55.5 136 25 155 55.2 137 25 165 52.9 138 25 175 53.2 139 25 185 52.4 140 25 195 53.4 141 25 205 53.4 142 25 215 55.0 143 25 225 56.5 144 25 235 59.8 145 25 245 53.3 146 25 255 49.9 147 25 265 57.4 148 25 275 50.6 149 25 285 51.4 150 25 295 51.4 151 25 305 53.4 152 25 315 54.2 153 25 325 56.0 154 25 335 58.2 155 25 345 54.6 160 15 35 51.2 161 15 45 47.0 162 15 55 47.8 163 15 65 47.6 164 15 75 41.7 165 15 85 54.8 166 15 95 48.4 167 15 105 57.2 168 15 115 53.1 169 15 125 51.0 170 15 135 52.2 171 15 145 49.3 172 15 155 49.9 173 15 165 51.3 174 15 175 51.8 175 15 185 52.6 176 15 195 51.3 177 15 205 49.5 178 15 215 54.5 179 15 225 57.7 180 15 235 59.4 181 15 245 56.5 182 15 255 41.9 183 15 265 34.2 184 15 275 45.9 185 15 285 46.5 186 15 295 46.4 187 15 305 48.6 188 15 315 49.0 189 15 325 52.1 190 15 335 53.1 191 15 345 51.9 193 5 5 56.4 197 5 45 45.0 198 5 55 50.9 199 5 65 51.7 200 5 75 48.1 201 5 85 52.2 202 5 95 50.9 203 5 105 53.8 204 5 115 52.9 205 5 125 50.0 206 5 135 48.2 207 5 145 50.9 208 5 155 53.2 209 5 165 57.1 210 5 175 58.4 211 5 185 57.0 212 5 195 54.3 213 5 205 57.7 214 5 215 58.3 215 5 225 57.1 216 5 235 56.5 217 5 245 55.7 218 5 255 55.4 219 5 265 53.9 220 5 275 48.1 221 5 285 52.2 223 5 305 51.1 224 5 315 55.8 225 5 325 57.9 226 5 335 60.8 227 5 345 55.8 228 5 355 56.6 229 -5 5 60.4 230 -5 15 58.3 232 -5 35 50.2 233 -5 45 46.1 234 -5 55 52.2 235 -5 65 52.0 236 -5 75 51.1 237 -5 85 51.8 238 -5 95 52.2 239 -5 105 53.8 240 -5 115 51.7 241 -5 125 48.6 242 -5 135 50.0 243 -5 145 53.0 244 -5 155 51.4 245 -5 165 55.2 246 -5 175 53.3 247 -5 185 52.8 248 -5 195 49.9 249 -5 205 49.4 250 -5 215 46.6 251 -5 225 45.2 252 -5 235 46.1 253 -5 245 50.4 254 -5 255 50.4 255 -5 265 52.4 256 -5 275 51.3 257 -5 285 50.1 260 -5 315 51.3 261 -5 325 48.9 262 -5 335 49.7 263 -5 345 50.6 264 -5 355 55.6 265 -15 5 61.3 266 -15 15 64.7 268 -15 35 46.6 269 -15 45 47.5 270 -15 55 49.9 271 -15 65 49.9 272 -15 75 50.4 273 -15 85 52.3 274 -15 95 53.5 275 -15 105 52.4 276 -15 115 50.1 277 -15 125 49.8 278 -15 135 55.4 279 -15 145 53.3 280 -15 155 50.4 281 -15 165 49.3 282 -15 175 52.7 283 -15 185 49.8 284 -15 195 50.9 285 -15 205 49.0 286 -15 215 49.7 287 -15 225 46.8 288 -15 235 48.1 289 -15 245 45.5 290 -15 255 50.8 291 -15 265 51.7 292 -15 275 60.4 293 -15 285 56.1 297 -15 325 49.1 298 -15 335 48.4 299 -15 345 48.6 300 -15 355 55.0 301 -25 5 58.2 302 -25 15 53.5 304 -25 35 51.8 305 -25 45 49.3 306 -25 55 50.0 307 -25 65 51.2 308 -25 75 49.2 309 -25 85 51.1 310 -25 95 56.3 311 -25 105 60.8 312 -25 115 49.1 315 -25 145 59.1 316 -25 155 52.6 317 -25 165 51.5 318 -25 175 51.7 319 -25 185 50.6 320 -25 195 51.4 321 -25 205 52.7 322 -25 215 51.7 323 -25 225 47.6 324 -25 235 44.5 325 -25 245 46.9 326 -25 255 48.0 327 -25 265 46.2 328 -25 275 60.9 329 -25 285 58.2 332 -25 315 53.1 333 -25 325 51.3 334 -25 335 48.6 335 -25 345 50.6 336 -25 355 51.6 337 -35 5 56.6 338 -35 15 51.5 339 -35 25 54.0 340 -35 35 60.0 341 -35 45 52.7 342 -35 55 54.8 343 -35 65 59.0 344 -35 75 57.3 345 -35 85 55.1 346 -35 95 59.1 347 -35 105 59.5 348 -35 115 58.0 349 -35 125 63.0 350 -35 135 60.2 351 -35 145 58.2 352 -35 155 56.8 353 -35 165 53.6 354 -35 175 47.9 355 -35 185 53.6 356 -35 195 55.9 357 -35 205 54.2 358 -35 215 54.3 359 -35 225 52.0 360 -35 235 53.6 361 -35 245 54.3 362 -35 255 53.1 363 -35 265 68.3 364 -35 275 68.0 365 -35 285 64.9 367 -35 305 57.2 368 -35 315 58.4 369 -35 325 59.6 370 -35 335 55.3 371 -35 345 55.1 372 -35 355 56.7 373 -45 5 66.3 374 -45 15 66.0 375 -45 25 64.5 376 -45 35 58.0 377 -45 45 72.3 378 -45 55 63.0 379 -45 65 65.7 380 -45 75 66.0 381 -45 85 67.8 382 -45 95 67.5 383 -45 105 63.4 384 -45 115 58.5 385 -45 125 56.7 386 -45 135 55.7 387 -45 145 59.0 388 -45 155 59.1 389 -45 165 59.3 390 -45 175 53.7 391 -45 185 59.7 392 -45 195 57.8 393 -45 205 59.4 394 -45 215 62.1 399 -45 265 70.3 400 -45 275 66.3 401 -45 285 65.8 402 -45 295 57.1 403 -45 305 60.1 404 -45 315 65.7 405 -45 325 73.1 406 -45 335 62.7 408 -45 355 77.0 409 -55 10 72.7 410 -55 30 70.9 411 -55 50 68.2 412 -55 70 65.1 413 -55 90 60.9 414 -55 110 68.4 415 -55 130 67.6 416 -55 150 61.3 417 -55 170 67.4 418 -55 190 63.8 419 -55 210 70.3 420 -55 230 65.2 421 -55 250 59.1 422 -55 270 64.4 423 -55 290 62.8 424 -55 310 69.0 425 -55 330 74.7 426 -55 350 77.0 427 -65 10 73.9 428 -65 30 67.4 429 -65 50 66.2 430 -65 70 76.6 431 -65 90 78.3 432 -65 110 77.9 433 -65 130 69.1 434 -65 150 67.1 435 -65 170 70.9 436 -65 190 71.9 437 -65 210 63.7 438 -65 230 78.6 439 -65 250 78.5 440 -65 270 80.4 441 -65 290 73.8 442 -65 310 77.1 443 -65 330 71.1 444 -65 350 72.7 449 -75 180 68.7 453 -75 340 58.4