Cumulonimbus Amount-When-Present (%) December, January, February (1954 - 1997) Day, Ship Observations Only Global Average: 56.8 Zonal Averages 16 zones Lat.N Average 75 83.5 65 72.9 55 69.4 45 66.3 35 61.1 25 53.4 15 49.3 5 52.9 -5 50.3 -15 49.2 -25 49.1 -35 54.8 -45 61.0 -55 64.5 -65 70.5 -75 65.9 Grid Box Averages 349 filled boxes Box # Lat.N Lon.E Average 4 75 20 81.5 5 75 60 88.7 12 75 340 80.5 13 65 10 69.8 14 65 30 86.8 15 65 50 84.5 21 65 170 81.3 22 65 190 80.0 29 65 330 70.7 30 65 350 74.2 31 55 10 64.3 32 55 30 78.3 38 55 150 78.3 39 55 170 69.5 40 55 190 69.0 41 55 210 65.9 42 55 230 67.8 46 55 310 80.6 47 55 330 67.6 48 55 350 63.5 49 45 5 58.2 50 45 15 61.5 51 45 25 79.9 52 45 35 83.4 53 45 45 69.8 54 45 55 69.6 62 45 135 80.5 63 45 145 75.9 64 45 155 71.6 65 45 165 64.5 66 45 175 62.5 67 45 185 60.9 68 45 195 59.9 69 45 205 61.5 70 45 215 61.7 71 45 225 62.6 72 45 235 62.1 77 45 285 78.1 78 45 295 78.0 79 45 305 77.4 80 45 315 74.5 81 45 325 66.6 82 45 335 62.0 83 45 345 61.9 84 45 355 64.5 85 35 5 58.9 86 35 15 59.3 87 35 25 58.9 88 35 35 57.0 97 35 125 78.1 98 35 135 72.5 99 35 145 67.0 100 35 155 63.1 101 35 165 60.8 102 35 175 59.2 103 35 185 58.3 104 35 195 58.4 105 35 205 58.3 106 35 215 59.6 107 35 225 58.8 108 35 235 57.6 109 35 245 54.4 112 35 275 59.9 113 35 285 62.9 114 35 295 68.0 115 35 305 62.5 116 35 315 59.5 117 35 325 58.1 118 35 335 59.6 119 35 345 59.2 120 35 355 56.7 124 25 35 46.5 126 25 55 47.1 127 25 65 43.9 132 25 115 68.3 133 25 125 66.3 134 25 135 57.3 135 25 145 54.4 136 25 155 54.0 137 25 165 51.4 138 25 175 52.4 139 25 185 52.4 140 25 195 51.5 141 25 205 51.8 142 25 215 53.8 143 25 225 55.5 144 25 235 56.9 145 25 245 50.5 146 25 255 46.7 147 25 265 55.7 148 25 275 50.4 149 25 285 50.2 150 25 295 50.3 151 25 305 52.2 152 25 315 52.7 153 25 325 54.0 154 25 335 56.2 155 25 345 51.5 160 15 35 50.6 161 15 45 45.6 162 15 55 45.2 163 15 65 45.4 164 15 75 37.9 165 15 85 53.4 166 15 95 48.5 167 15 105 56.9 168 15 115 52.2 169 15 125 49.5 170 15 135 51.0 171 15 145 48.5 172 15 155 49.1 173 15 165 49.4 174 15 175 49.6 175 15 185 50.7 176 15 195 49.3 177 15 205 48.7 178 15 215 52.2 179 15 225 56.8 180 15 235 58.9 181 15 245 53.8 182 15 255 39.3 183 15 265 32.0 184 15 275 45.6 185 15 285 45.0 186 15 295 45.6 187 15 305 47.7 188 15 315 47.9 189 15 325 50.9 190 15 335 53.5 191 15 345 48.7 193 5 5 58.4 197 5 45 45.3 198 5 55 49.8 199 5 65 49.9 200 5 75 46.0 201 5 85 51.5 202 5 95 49.5 203 5 105 53.5 204 5 115 51.0 205 5 125 48.3 206 5 135 46.9 207 5 145 51.0 208 5 155 51.8 209 5 165 54.0 210 5 175 58.0 211 5 185 56.2 212 5 195 53.4 213 5 205 55.0 214 5 215 55.9 215 5 225 54.0 216 5 235 56.2 217 5 245 52.7 218 5 255 53.8 219 5 265 51.6 220 5 275 47.9 221 5 285 52.6 223 5 305 50.6 224 5 315 54.9 225 5 325 56.7 226 5 335 61.4 227 5 345 55.4 228 5 355 55.3 229 -5 5 59.2 230 -5 15 58.4 232 -5 35 47.6 233 -5 45 46.1 234 -5 55 52.1 235 -5 65 51.7 236 -5 75 50.7 237 -5 85 50.9 238 -5 95 51.0 239 -5 105 53.4 240 -5 115 50.3 241 -5 125 46.2 242 -5 135 49.4 243 -5 145 51.2 244 -5 155 50.9 245 -5 165 52.2 246 -5 175 52.1 247 -5 185 54.5 248 -5 195 49.6 249 -5 205 49.9 250 -5 215 45.7 251 -5 225 46.1 252 -5 235 43.0 253 -5 245 46.6 254 -5 255 47.3 255 -5 265 49.8 256 -5 275 47.7 260 -5 315 49.5 261 -5 325 48.5 262 -5 335 49.6 263 -5 345 48.9 264 -5 355 52.6 265 -15 5 55.9 266 -15 15 62.5 268 -15 35 45.9 269 -15 45 46.5 270 -15 55 48.4 271 -15 65 49.3 272 -15 75 48.3 273 -15 85 50.6 274 -15 95 53.1 275 -15 105 51.3 276 -15 115 50.2 277 -15 125 49.7 278 -15 135 54.8 279 -15 145 51.8 280 -15 155 49.3 281 -15 165 49.5 282 -15 175 51.9 283 -15 185 50.0 284 -15 195 51.2 285 -15 205 48.3 286 -15 215 49.2 287 -15 225 47.4 288 -15 235 45.5 289 -15 245 45.7 290 -15 255 46.4 291 -15 265 44.4 292 -15 275 53.1 293 -15 285 54.5 297 -15 325 47.7 298 -15 335 49.5 299 -15 345 45.5 300 -15 355 50.6 301 -25 5 52.7 302 -25 15 52.0 304 -25 35 49.4 305 -25 45 46.2 306 -25 55 47.2 307 -25 65 49.4 308 -25 75 47.4 309 -25 85 50.0 310 -25 95 54.6 311 -25 105 58.6 312 -25 115 46.4 315 -25 145 51.4 316 -25 155 51.6 317 -25 165 51.2 318 -25 175 50.8 319 -25 185 50.9 320 -25 195 51.1 321 -25 205 52.2 322 -25 215 50.3 323 -25 225 46.6 324 -25 235 44.3 325 -25 245 47.0 326 -25 255 43.4 327 -25 265 44.2 328 -25 275 53.6 329 -25 285 56.7 332 -25 315 50.3 333 -25 325 50.9 334 -25 335 49.8 335 -25 345 48.8 336 -25 355 48.4 337 -35 5 55.4 338 -35 15 50.5 339 -35 25 51.2 340 -35 35 54.9 341 -35 45 54.3 342 -35 55 55.0 343 -35 65 54.0 344 -35 75 56.3 345 -35 85 55.1 346 -35 95 54.8 347 -35 105 59.9 348 -35 115 57.3 349 -35 125 62.4 350 -35 135 58.9 351 -35 145 55.3 352 -35 155 55.1 353 -35 165 52.9 354 -35 175 46.2 355 -35 185 52.2 356 -35 195 53.5 357 -35 205 54.8 358 -35 215 52.2 359 -35 225 48.0 360 -35 235 52.1 361 -35 245 52.2 363 -35 265 62.3 364 -35 275 67.5 365 -35 285 62.0 367 -35 305 57.6 368 -35 315 59.7 369 -35 325 59.7 370 -35 335 54.8 371 -35 345 51.7 372 -35 355 55.1 373 -45 5 65.0 374 -45 15 62.3 375 -45 25 64.1 376 -45 35 60.4 377 -45 45 65.3 378 -45 55 64.3 379 -45 65 66.7 380 -45 75 65.0 381 -45 85 64.6 382 -45 95 64.5 383 -45 105 64.1 384 -45 115 57.2 385 -45 125 57.6 386 -45 135 57.0 387 -45 145 58.0 388 -45 155 57.4 389 -45 165 58.0 390 -45 175 50.8 391 -45 185 59.6 392 -45 195 57.6 393 -45 205 58.2 400 -45 275 63.8 401 -45 285 65.8 402 -45 295 57.0 403 -45 305 58.8 404 -45 315 62.5 405 -45 325 68.5 409 -55 10 69.7 410 -55 30 70.5 411 -55 50 68.1 412 -55 70 62.4 413 -55 90 59.1 415 -55 130 64.6 416 -55 150 57.2 417 -55 170 65.6 418 -55 190 63.0 421 -55 250 56.9 422 -55 270 64.7 423 -55 290 62.9 424 -55 310 68.4 425 -55 330 71.7 426 -55 350 75.9 427 -65 10 72.7 428 -65 30 66.8 429 -65 50 64.1 430 -65 70 76.5 431 -65 90 80.0 432 -65 110 75.4 433 -65 130 64.6 435 -65 170 71.5 436 -65 190 67.4 437 -65 210 62.4 439 -65 250 75.2 441 -65 290 70.1 442 -65 310 76.0 444 -65 350 70.1 449 -75 180 69.4 453 -75 340 60.7