Cumulonimbus Amount-When-Present (%) June, July, August (1954 - 1997) Night, Ship Observations Only Global Average: 57.7 Zonal Averages 15 zones Lat.N Average 85 66.9 75 81.2 65 73.3 55 70.5 45 66.8 35 53.6 25 46.6 15 51.6 5 54.9 -5 51.7 -15 56.0 -25 55.2 -35 59.5 -45 63.0 -55 65.3 Grid Box Averages 290 filled boxes Box # Lat.N Lon.E Average 1 85 60 66.9 4 75 20 78.7 5 75 60 84.4 6 75 100 83.8 7 75 140 80.6 11 75 300 66.0 12 75 340 84.0 13 65 10 72.4 14 65 30 79.9 15 65 50 78.7 21 65 170 72.1 22 65 190 66.5 27 65 290 72.5 28 65 310 70.0 29 65 330 72.9 30 65 350 74.5 31 55 10 64.3 32 55 30 67.2 38 55 150 78.1 39 55 170 78.7 40 55 190 72.8 41 55 210 68.5 42 55 230 70.6 45 55 290 68.5 46 55 310 72.0 47 55 330 74.3 48 55 350 65.5 49 45 5 51.1 50 45 15 44.9 51 45 25 57.7 52 45 35 71.8 62 45 135 79.2 63 45 145 79.3 64 45 155 74.2 65 45 165 76.1 66 45 175 78.5 67 45 185 75.2 68 45 195 69.1 69 45 205 70.7 70 45 215 70.5 71 45 225 67.9 72 45 235 65.3 77 45 285 60.3 78 45 295 62.6 79 45 305 63.5 80 45 315 67.7 81 45 325 66.5 82 45 335 64.7 83 45 345 62.3 84 45 355 59.8 85 35 5 52.4 86 35 15 45.0 87 35 25 43.1 88 35 35 48.0 97 35 125 62.9 98 35 135 52.6 99 35 145 54.1 100 35 155 55.5 101 35 165 53.1 102 35 175 53.0 103 35 185 48.5 104 35 195 50.6 105 35 205 53.1 106 35 215 61.5 107 35 225 65.8 108 35 235 65.7 109 35 245 67.0 112 35 275 43.9 113 35 285 46.6 114 35 295 50.9 115 35 305 52.0 116 35 315 49.3 117 35 325 52.4 118 35 335 59.5 119 35 345 60.3 120 35 355 52.9 126 25 55 58.9 127 25 65 62.3 129 25 85 62.7 132 25 115 51.5 133 25 125 45.4 134 25 135 43.3 135 25 145 44.1 136 25 155 44.6 137 25 165 44.3 138 25 175 43.1 139 25 185 44.4 140 25 195 45.8 141 25 205 50.9 142 25 215 57.8 143 25 225 67.5 144 25 235 73.0 145 25 245 56.0 146 25 255 48.0 147 25 265 40.3 148 25 275 39.2 149 25 285 41.5 150 25 295 43.9 151 25 305 46.0 152 25 315 47.9 153 25 325 54.0 154 25 335 57.5 155 25 345 61.0 161 15 45 55.4 162 15 55 54.4 163 15 65 60.1 164 15 75 59.4 165 15 85 63.7 166 15 95 61.8 167 15 105 34.7 168 15 115 50.8 169 15 125 48.2 170 15 135 47.9 171 15 145 47.9 172 15 155 47.9 173 15 165 45.4 174 15 175 45.2 175 15 185 47.0 176 15 195 49.3 177 15 205 52.2 178 15 215 57.3 179 15 225 64.0 180 15 235 59.9 181 15 245 55.4 182 15 255 52.3 183 15 265 51.6 184 15 275 47.5 185 15 285 45.4 186 15 295 46.0 187 15 305 50.6 188 15 315 52.3 189 15 325 57.0 190 15 335 59.0 191 15 345 63.4 193 5 5 67.2 197 5 45 50.8 198 5 55 50.3 199 5 65 51.2 200 5 75 53.1 201 5 85 51.1 202 5 95 51.8 203 5 105 48.8 204 5 115 47.5 205 5 125 52.2 206 5 135 51.1 207 5 145 50.8 208 5 155 51.8 209 5 165 49.8 210 5 175 57.5 211 5 185 55.6 212 5 195 52.9 213 5 205 56.5 214 5 215 61.3 215 5 225 50.0 216 5 235 55.1 217 5 245 56.2 218 5 255 60.8 219 5 265 62.2 220 5 275 58.7 221 5 285 56.1 223 5 305 52.3 224 5 315 52.3 225 5 325 56.0 226 5 335 64.5 227 5 345 67.8 228 5 355 68.8 229 -5 5 61.5 233 -5 45 51.8 234 -5 55 54.2 235 -5 65 54.4 236 -5 75 55.2 237 -5 85 51.3 238 -5 95 50.4 239 -5 105 50.4 240 -5 115 44.3 241 -5 125 46.5 242 -5 135 52.2 243 -5 145 53.5 244 -5 155 54.7 245 -5 165 55.6 246 -5 175 47.9 247 -5 185 46.1 248 -5 195 49.0 249 -5 205 49.0 250 -5 215 44.6 251 -5 225 51.0 252 -5 235 49.3 253 -5 245 46.6 254 -5 255 57.4 255 -5 265 59.0 256 -5 275 71.9 260 -5 315 44.5 261 -5 325 56.0 262 -5 335 53.1 263 -5 345 46.2 264 -5 355 56.9 265 -15 5 71.4 266 -15 15 64.4 268 -15 35 54.2 269 -15 45 48.2 270 -15 55 54.7 271 -15 65 57.3 272 -15 75 56.3 273 -15 85 58.9 274 -15 95 57.4 275 -15 105 57.5 276 -15 115 49.9 278 -15 135 58.5 279 -15 145 59.0 280 -15 155 56.3 281 -15 165 58.4 282 -15 175 57.7 283 -15 185 51.4 284 -15 195 56.7 285 -15 205 54.7 286 -15 215 56.1 287 -15 225 51.3 288 -15 235 51.5 289 -15 245 54.8 290 -15 255 58.3 292 -15 275 69.8 297 -15 325 54.3 298 -15 335 54.9 299 -15 345 53.0 300 -15 355 64.9 301 -25 5 62.9 302 -25 15 56.5 304 -25 35 54.0 305 -25 45 53.3 306 -25 55 52.6 307 -25 65 53.9 308 -25 75 49.7 309 -25 85 58.9 310 -25 95 54.2 311 -25 105 55.8 312 -25 115 60.7 316 -25 155 55.0 317 -25 165 51.5 318 -25 175 53.3 319 -25 185 54.4 320 -25 195 57.2 321 -25 205 55.0 322 -25 215 63.2 323 -25 225 55.6 324 -25 235 50.5 325 -25 245 51.0 328 -25 275 64.2 332 -25 315 59.0 333 -25 325 55.3 334 -25 335 54.5 335 -25 345 61.5 336 -25 355 53.1 337 -35 5 61.8 338 -35 15 55.7 339 -35 25 56.7 340 -35 35 58.2 341 -35 45 61.0 342 -35 55 56.5 343 -35 65 59.2 344 -35 75 68.4 345 -35 85 67.3 346 -35 95 58.5 347 -35 105 59.9 348 -35 115 60.6 349 -35 125 58.5 350 -35 135 60.3 351 -35 145 63.7 352 -35 155 56.6 353 -35 165 56.4 354 -35 175 54.0 355 -35 185 53.8 356 -35 195 57.4 357 -35 205 54.7 358 -35 215 51.6 364 -35 275 69.8 367 -35 305 73.6 368 -35 315 66.9 369 -35 325 66.2 371 -35 345 60.8 372 -35 355 60.3 388 -45 155 59.0 389 -45 165 61.4 390 -45 175 57.5 391 -45 185 62.6 400 -45 275 74.0 402 -45 295 64.0 403 -45 305 64.8 423 -55 290 60.8 424 -55 310 66.4 425 -55 330 69.2