Stratus Amount-When-Present (%) March, April, May (1954 - 1997) Night, Ship Observations Only Global Average: 84.0 Zonal Averages 17 zones Lat.N Average 85 87.2 75 89.6 65 86.5 55 90.3 45 89.9 35 85.6 25 81.3 15 75.6 5 80.0 -5 79.3 -15 80.3 -25 82.7 -35 85.7 -45 89.0 -55 92.1 -65 90.3 -75 89.0 Grid Box Averages 329 filled boxes Box # Lat.N Lon.E Average 1 85 60 87.1 2 85 180 89.6 3 85 300 84.8 4 75 20 89.1 5 75 60 91.8 7 75 140 84.7 8 75 180 94.2 9 75 220 93.2 12 75 340 84.2 13 65 10 84.3 14 65 30 88.5 15 65 50 83.6 20 65 150 87.3 21 65 170 96.2 22 65 190 93.5 23 65 210 89.7 29 65 330 83.0 30 65 350 84.9 31 55 10 84.8 32 55 30 81.4 38 55 150 91.5 39 55 170 94.1 40 55 190 92.0 41 55 210 91.3 42 55 230 91.5 46 55 310 88.0 47 55 330 88.6 48 55 350 86.5 49 45 5 75.7 50 45 15 74.3 51 45 25 85.4 52 45 35 84.1 62 45 135 86.1 63 45 145 87.2 64 45 155 91.4 65 45 165 92.4 66 45 175 92.2 67 45 185 91.6 68 45 195 90.7 69 45 205 92.0 70 45 215 91.5 71 45 225 90.6 72 45 235 88.3 77 45 285 82.0 78 45 295 87.3 79 45 305 89.1 80 45 315 89.0 81 45 325 88.8 82 45 335 88.3 83 45 345 87.1 84 45 355 84.7 85 35 5 76.2 86 35 15 71.9 87 35 25 71.9 88 35 35 73.5 97 35 125 83.9 98 35 135 83.4 99 35 145 87.1 100 35 155 89.4 101 35 165 88.5 102 35 175 88.4 103 35 185 88.5 104 35 195 88.0 105 35 205 88.9 106 35 215 88.2 107 35 225 87.6 108 35 235 87.0 109 35 245 84.9 112 35 275 74.3 113 35 285 78.4 114 35 295 84.1 115 35 305 84.0 116 35 315 81.0 117 35 325 82.5 118 35 335 83.4 119 35 345 82.0 120 35 355 74.0 124 25 35 66.8 126 25 55 67.3 127 25 65 59.6 132 25 115 86.2 133 25 125 85.7 134 25 135 82.2 135 25 145 82.7 136 25 155 84.3 137 25 165 82.7 138 25 175 82.1 139 25 185 81.8 140 25 195 81.4 141 25 205 82.3 142 25 215 84.7 143 25 225 84.7 144 25 235 85.1 145 25 245 80.0 146 25 255 64.0 147 25 265 75.3 148 25 275 71.4 149 25 285 72.5 150 25 295 77.6 151 25 305 78.9 152 25 315 78.7 153 25 325 80.2 154 25 335 76.2 155 25 345 73.7 161 15 45 60.0 162 15 55 67.2 163 15 65 65.6 164 15 75 68.6 165 15 85 54.7 166 15 95 59.3 167 15 105 78.4 168 15 115 72.0 169 15 125 76.0 170 15 135 77.9 171 15 145 78.3 172 15 155 77.4 173 15 165 80.4 174 15 175 79.9 175 15 185 73.0 176 15 195 77.0 177 15 205 78.6 178 15 215 81.4 179 15 225 86.6 180 15 235 86.9 181 15 245 79.3 182 15 255 63.4 183 15 265 62.6 184 15 275 69.2 185 15 285 70.2 186 15 295 70.0 187 15 305 71.5 188 15 315 73.6 189 15 325 75.3 190 15 335 68.5 191 15 345 67.3 193 5 5 75.2 198 5 55 72.2 199 5 65 70.3 200 5 75 70.1 201 5 85 72.8 202 5 95 74.1 203 5 105 68.0 204 5 115 72.1 205 5 125 78.4 206 5 135 79.5 207 5 145 83.4 208 5 155 84.3 209 5 165 80.6 210 5 175 82.1 211 5 185 83.6 212 5 195 84.7 213 5 205 81.5 214 5 215 86.5 215 5 225 84.3 216 5 235 84.0 217 5 245 76.8 218 5 255 85.8 219 5 265 76.7 220 5 275 76.6 221 5 285 75.3 223 5 305 79.1 224 5 315 78.6 225 5 325 82.0 226 5 335 78.1 227 5 345 74.9 228 5 355 74.0 229 -5 5 72.8 233 -5 45 75.2 234 -5 55 75.2 235 -5 65 81.3 236 -5 75 80.5 237 -5 85 77.9 238 -5 95 79.3 239 -5 105 73.4 240 -5 115 76.3 241 -5 125 80.1 242 -5 135 77.0 243 -5 145 81.2 244 -5 155 82.6 245 -5 165 83.8 246 -5 175 83.2 247 -5 185 76.4 248 -5 195 77.3 252 -5 235 82.5 253 -5 245 83.5 254 -5 255 85.5 255 -5 265 84.0 256 -5 275 74.7 260 -5 315 75.2 261 -5 325 77.0 262 -5 335 79.2 263 -5 345 70.0 264 -5 355 75.2 265 -15 5 86.8 266 -15 15 82.4 269 -15 45 74.3 270 -15 55 77.8 271 -15 65 78.9 272 -15 75 75.5 273 -15 85 78.7 274 -15 95 78.7 275 -15 105 76.7 276 -15 115 79.0 277 -15 125 83.7 278 -15 135 79.8 279 -15 145 83.7 280 -15 155 83.4 281 -15 165 81.5 282 -15 175 80.6 283 -15 185 80.3 284 -15 195 79.5 285 -15 205 82.8 286 -15 215 81.3 289 -15 245 78.4 290 -15 255 81.9 292 -15 275 84.2 293 -15 285 78.2 297 -15 325 75.3 299 -15 345 72.8 300 -15 355 84.2 301 -25 5 85.9 302 -25 15 83.3 304 -25 35 79.5 305 -25 45 76.4 306 -25 55 84.4 307 -25 65 82.8 308 -25 75 78.0 309 -25 85 79.5 310 -25 95 81.5 311 -25 105 80.6 312 -25 115 73.8 316 -25 155 84.3 317 -25 165 83.3 318 -25 175 83.8 319 -25 185 81.7 320 -25 195 84.2 321 -25 205 85.4 322 -25 215 86.1 323 -25 225 82.3 324 -25 235 85.9 328 -25 275 86.8 329 -25 285 89.7 332 -25 315 75.2 333 -25 325 75.5 334 -25 335 79.8 335 -25 345 83.5 336 -25 355 82.0 337 -35 5 83.8 338 -35 15 79.4 339 -35 25 84.1 340 -35 35 80.6 341 -35 45 87.0 342 -35 55 84.3 343 -35 65 85.3 344 -35 75 85.4 345 -35 85 87.5 346 -35 95 89.2 347 -35 105 84.4 348 -35 115 82.3 349 -35 125 85.3 350 -35 135 84.2 351 -35 145 85.9 352 -35 155 84.5 353 -35 165 85.3 354 -35 175 85.4 355 -35 185 84.5 356 -35 195 88.2 357 -35 205 88.2 358 -35 215 85.8 359 -35 225 87.4 360 -35 235 91.1 363 -35 265 84.0 364 -35 275 87.7 365 -35 285 88.0 367 -35 305 80.2 368 -35 315 79.5 369 -35 325 86.3 370 -35 335 86.5 371 -35 345 86.2 372 -35 355 84.4 373 -45 5 90.2 376 -45 35 89.9 377 -45 45 85.9 378 -45 55 93.1 380 -45 75 87.5 381 -45 85 90.5 382 -45 95 93.8 386 -45 135 91.0 387 -45 145 78.8 388 -45 155 87.7 389 -45 165 91.0 390 -45 175 84.9 391 -45 185 87.3 392 -45 195 86.3 393 -45 205 92.6 399 -45 265 85.1 400 -45 275 92.2 401 -45 285 92.1 402 -45 295 84.5 403 -45 305 83.0 404 -45 315 89.1 405 -45 325 90.3 409 -55 10 95.0 410 -55 30 95.0 411 -55 50 88.1 412 -55 70 89.7 413 -55 90 96.3 417 -55 170 87.6 418 -55 190 92.2 421 -55 250 97.4 422 -55 270 88.0 423 -55 290 88.2 424 -55 310 90.6 425 -55 330 84.7 426 -55 350 97.5 427 -65 10 88.6 428 -65 30 90.7 429 -65 50 86.1 430 -65 70 91.8 431 -65 90 91.3 434 -65 150 90.9 435 -65 170 88.3 437 -65 210 92.1 440 -65 270 96.6 441 -65 290 89.6 442 -65 310 87.8 449 -75 180 89.3 450 -75 220 91.3 453 -75 340 85.0