Cumulus Average Cloud Amount (%) April (1954 - 1997) Night, Ship Observations Only Global Average: 12.1 Zonal Averages 16 zones Lat.N Average 85 1.0 75 2.4 65 5.9 55 6.2 45 6.4 35 9.7 25 14.1 15 17.6 5 16.1 -5 17.5 -15 17.2 -25 15.2 -35 10.9 -45 7.9 -55 6.9 -65 2.4 Grid Box Averages 330 filled boxes Box # Lat.N Lon.E Average 1 85 60 2.2 2 85 180 0.2 3 85 300 0.4 4 75 20 6.7 5 75 60 3.4 7 75 140 0.7 8 75 180 0.3 9 75 220 0.7 12 75 340 2.3 13 65 10 6.1 14 65 30 6.4 15 65 50 3.2 21 65 170 4.3 22 65 190 3.8 23 65 210 3.0 29 65 330 6.8 30 65 350 7.1 31 55 10 5.2 32 55 30 4.4 38 55 150 4.3 39 55 170 5.5 40 55 190 5.5 41 55 210 6.0 42 55 230 7.2 46 55 310 10.0 47 55 330 6.3 48 55 350 5.4 49 45 5 7.2 50 45 15 6.3 51 45 25 3.5 52 45 35 3.9 53 45 45 4.8 54 45 55 3.5 62 45 135 4.4 63 45 145 4.7 64 45 155 4.2 65 45 165 3.9 66 45 175 5.2 67 45 185 5.6 68 45 195 5.5 69 45 205 5.8 70 45 215 7.3 71 45 225 8.7 72 45 235 9.3 77 45 285 3.8 78 45 295 4.4 79 45 305 5.1 80 45 315 8.0 81 45 325 9.0 82 45 335 7.9 83 45 345 8.1 84 45 355 8.9 85 35 5 8.0 86 35 15 7.8 87 35 25 8.0 88 35 35 9.6 97 35 125 5.1 98 35 135 8.5 99 35 145 9.2 100 35 155 8.2 101 35 165 7.7 102 35 175 7.6 103 35 185 8.2 104 35 195 8.0 105 35 205 8.1 106 35 215 8.5 107 35 225 10.3 108 35 235 10.0 109 35 245 8.5 112 35 275 8.7 113 35 285 9.7 114 35 295 12.3 115 35 305 13.0 116 35 315 13.9 117 35 325 12.0 118 35 335 12.3 119 35 345 12.4 120 35 355 8.3 124 25 35 2.0 125 25 45 4.7 126 25 55 3.0 127 25 65 6.7 129 25 85 12.4 132 25 115 9.8 133 25 125 10.5 134 25 135 11.6 135 25 145 15.1 136 25 155 14.5 137 25 165 13.1 138 25 175 14.7 139 25 185 15.7 140 25 195 17.9 141 25 205 18.0 142 25 215 14.6 143 25 225 11.7 144 25 235 10.9 145 25 245 10.1 146 25 255 9.3 147 25 265 9.0 148 25 275 15.0 149 25 285 15.6 150 25 295 18.3 151 25 305 18.1 152 25 315 17.1 153 25 325 16.8 154 25 335 17.2 155 25 345 10.9 160 15 35 3.5 161 15 45 8.8 162 15 55 15.3 163 15 65 13.9 164 15 75 15.6 165 15 85 19.8 166 15 95 18.5 167 15 105 12.3 168 15 115 18.8 169 15 125 16.8 170 15 135 19.9 171 15 145 19.4 172 15 155 22.5 173 15 165 24.5 174 15 175 20.7 175 15 185 20.5 176 15 195 21.4 177 15 205 16.7 178 15 215 15.2 179 15 225 14.2 180 15 235 12.5 181 15 245 15.5 182 15 255 12.4 183 15 265 11.7 184 15 275 17.1 185 15 285 18.9 186 15 295 19.7 187 15 305 21.3 188 15 315 20.7 189 15 325 19.4 190 15 335 15.8 191 15 345 3.5 193 5 5 16.3 197 5 45 21.2 198 5 55 20.7 199 5 65 20.8 200 5 75 17.4 201 5 85 17.2 202 5 95 15.8 203 5 105 19.1 204 5 115 17.5 205 5 125 16.5 206 5 135 16.6 207 5 145 16.2 208 5 155 12.8 209 5 165 18.9 210 5 175 19.4 211 5 185 15.2 212 5 195 18.6 213 5 205 14.4 214 5 215 11.4 215 5 225 12.4 216 5 235 15.6 217 5 245 15.6 218 5 255 15.0 219 5 265 16.3 220 5 275 12.0 221 5 285 11.1 223 5 305 18.8 224 5 315 15.7 225 5 325 15.7 226 5 335 16.6 227 5 345 10.8 228 5 355 15.3 229 -5 5 18.2 230 -5 15 14.8 233 -5 45 19.7 234 -5 55 20.1 235 -5 65 17.6 236 -5 75 18.5 237 -5 85 16.8 238 -5 95 18.1 239 -5 105 14.8 240 -5 115 13.7 241 -5 125 15.9 242 -5 135 16.4 243 -5 145 15.7 244 -5 155 14.2 245 -5 165 16.1 246 -5 175 13.7 247 -5 185 20.6 248 -5 195 18.8 249 -5 205 22.9 250 -5 215 17.4 251 -5 225 20.4 252 -5 235 21.0 253 -5 245 18.0 254 -5 255 18.5 255 -5 265 13.8 256 -5 275 10.0 260 -5 315 16.7 261 -5 325 18.2 262 -5 335 17.9 263 -5 345 18.4 264 -5 355 18.6 265 -15 5 9.4 266 -15 15 8.5 268 -15 35 19.0 269 -15 45 17.1 270 -15 55 19.1 271 -15 65 18.1 272 -15 75 17.6 273 -15 85 17.0 274 -15 95 16.2 275 -15 105 20.1 276 -15 115 12.6 277 -15 125 10.6 278 -15 135 15.5 279 -15 145 17.3 280 -15 155 17.4 281 -15 165 19.1 282 -15 175 15.4 283 -15 185 16.0 284 -15 195 18.1 285 -15 205 19.1 286 -15 215 21.9 287 -15 225 22.3 288 -15 235 20.6 289 -15 245 21.8 290 -15 255 18.8 291 -15 265 12.3 292 -15 275 16.4 293 -15 285 8.6 297 -15 325 19.9 298 -15 335 20.6 299 -15 345 18.4 300 -15 355 12.8 301 -25 5 9.7 302 -25 15 8.2 304 -25 35 17.1 305 -25 45 18.0 306 -25 55 16.5 307 -25 65 16.7 308 -25 75 17.7 309 -25 85 14.4 310 -25 95 14.3 311 -25 105 17.9 312 -25 115 11.3 316 -25 155 17.1 317 -25 165 18.3 318 -25 175 13.5 319 -25 185 16.6 320 -25 195 14.1 321 -25 205 15.1 322 -25 215 15.1 323 -25 225 16.7 324 -25 235 17.2 325 -25 245 17.4 326 -25 255 15.2 327 -25 265 15.2 328 -25 275 11.9 329 -25 285 7.3 332 -25 315 13.5 333 -25 325 17.3 334 -25 335 16.7 335 -25 345 16.5 336 -25 355 13.2 337 -35 5 7.3 338 -35 15 7.7 339 -35 25 9.0 340 -35 35 14.1 341 -35 45 14.7 342 -35 55 12.9 343 -35 65 8.7 344 -35 75 8.8 345 -35 85 8.7 346 -35 95 6.2 347 -35 105 12.0 348 -35 115 11.1 349 -35 125 9.7 350 -35 135 8.6 351 -35 145 8.8 352 -35 155 12.5 353 -35 165 12.3 354 -35 175 12.2 355 -35 185 12.3 356 -35 195 13.3 357 -35 205 12.1 358 -35 215 11.5 359 -35 225 9.7 360 -35 235 12.8 363 -35 265 8.6 364 -35 275 15.8 365 -35 285 8.3 367 -35 305 10.9 368 -35 315 14.2 369 -35 325 12.1 370 -35 335 10.0 371 -35 345 9.1 372 -35 355 9.9 373 -45 5 4.2 377 -45 45 5.3 380 -45 75 4.6 381 -45 85 4.5 382 -45 95 5.2 386 -45 135 8.9 387 -45 145 8.1 388 -45 155 8.0 389 -45 165 8.5 390 -45 175 6.0 391 -45 185 6.1 392 -45 195 8.5 393 -45 205 9.8 394 -45 215 10.0 399 -45 265 11.9 400 -45 275 11.6 401 -45 285 9.8 402 -45 295 9.5 403 -45 305 8.8 404 -45 315 10.8 405 -45 325 6.8 409 -55 10 3.2 417 -55 170 6.3 422 -55 270 9.4 423 -55 290 8.1 424 -55 310 8.8 425 -55 330 5.5 427 -65 10 1.7 429 -65 50 1.7 430 -65 70 1.5 431 -65 90 1.4 433 -65 130 4.9 442 -65 310 3.5