Nimbostratus Amount-When-Present (%) December, January, February (1954 - 1997) Night, Ship Observations Only Global Average: 98.8 Zonal Averages 33 zones Lat.N Average 87.5 97.1 77.5 98.6 72.5 98.7 67.5 99.1 62.5 99.3 57.5 99.4 52.5 99.3 47.5 99.2 42.5 99.2 37.5 99.0 32.5 98.9 27.5 98.8 22.5 99.0 17.5 98.7 12.5 98.4 7.5 98.3 2.5 98.8 -2.5 97.8 -7.5 98.7 -12.5 98.5 -17.5 98.4 -22.5 98.4 -27.5 99.1 -32.5 98.8 -37.5 98.8 -42.5 98.6 -47.5 99.4 -52.5 99.5 -57.5 99.6 -62.5 99.5 -67.5 99.4 -72.5 99.6 -77.5 98.9 Grid Box Averages 424 filled boxes Box # Lat.N Lon.E Average 1 87.5 0.0 97.1 11 77.5 10.0 98.6 29 72.5 10.0 98.9 30 72.5 30.0 98.9 31 72.5 50.0 98.4 47 67.5 5.0 99.3 48 67.5 15.0 99.2 50 67.5 35.0 98.7 51 67.5 45.0 98.7 81 67.5 345.0 99.5 82 67.5 355.0 99.2 83 62.5 5.0 98.9 99 62.5 165.0 100.0 100 62.5 175.0 99.6 101 62.5 185.0 99.6 115 62.5 325.0 98.9 117 62.5 345.0 99.0 118 62.5 355.0 98.8 119 57.5 5.0 99.1 120 57.5 15.0 99.4 121 57.5 25.0 99.7 133 57.5 145.0 99.5 134 57.5 155.0 99.6 135 57.5 165.0 99.7 136 57.5 175.0 99.5 137 57.5 185.0 99.4 138 57.5 195.0 99.1 139 57.5 205.0 99.1 140 57.5 215.0 99.2 141 57.5 225.0 99.2 149 57.5 305.0 99.4 150 57.5 315.0 98.9 151 57.5 325.0 99.0 152 57.5 335.0 99.2 153 57.5 345.0 99.4 154 57.5 355.0 99.3 155 52.5 5.0 99.7 169 52.5 145.0 99.6 170 52.5 155.0 99.4 171 52.5 165.0 98.9 172 52.5 175.0 99.0 173 52.5 185.0 99.0 174 52.5 195.0 99.2 175 52.5 205.0 99.5 176 52.5 215.0 99.3 177 52.5 225.0 99.4 178 52.5 235.0 99.5 185 52.5 305.0 99.3 186 52.5 315.0 98.9 187 52.5 325.0 99.5 188 52.5 335.0 99.0 189 52.5 345.0 99.4 190 52.5 355.0 99.2 218 47.5 137.5 99.5 219 47.5 142.5 99.4 220 47.5 147.5 99.3 221 47.5 152.5 99.3 222 47.5 157.5 98.9 223 47.5 162.5 98.0 224 47.5 167.5 98.8 225 47.5 172.5 98.4 226 47.5 177.5 98.9 227 47.5 182.5 99.3 228 47.5 187.5 99.4 229 47.5 192.5 99.8 230 47.5 197.5 99.5 231 47.5 202.5 99.1 232 47.5 207.5 99.3 233 47.5 212.5 99.7 234 47.5 217.5 99.6 235 47.5 222.5 99.2 236 47.5 227.5 99.3 237 47.5 232.5 99.3 238 47.5 237.5 99.6 251 47.5 302.5 99.6 252 47.5 307.5 99.4 253 47.5 312.5 99.4 254 47.5 317.5 98.9 255 47.5 322.5 98.8 256 47.5 327.5 99.1 257 47.5 332.5 99.1 258 47.5 337.5 99.5 259 47.5 342.5 99.0 260 47.5 347.5 99.1 261 47.5 352.5 99.0 262 47.5 357.5 99.2 263 42.5 2.5 99.0 264 42.5 7.5 99.3 265 42.5 12.5 98.8 266 42.5 17.5 99.1 269 42.5 32.5 99.2 289 42.5 132.5 99.9 290 42.5 137.5 99.4 291 42.5 142.5 98.9 292 42.5 147.5 99.3 293 42.5 152.5 98.5 294 42.5 157.5 98.4 295 42.5 162.5 98.7 296 42.5 167.5 98.7 297 42.5 172.5 99.5 298 42.5 177.5 99.0 299 42.5 182.5 98.7 300 42.5 187.5 99.3 301 42.5 192.5 99.5 302 42.5 197.5 99.1 303 42.5 202.5 99.3 304 42.5 207.5 99.6 305 42.5 212.5 99.5 306 42.5 217.5 99.6 307 42.5 222.5 99.5 308 42.5 227.5 99.7 309 42.5 232.5 98.8 310 42.5 237.5 99.2 320 42.5 287.5 99.7 321 42.5 292.5 99.4 322 42.5 297.5 99.4 323 42.5 302.5 99.5 324 42.5 307.5 99.3 325 42.5 312.5 99.2 326 42.5 317.5 99.2 327 42.5 322.5 99.3 328 42.5 327.5 98.8 329 42.5 332.5 98.7 330 42.5 337.5 99.2 331 42.5 342.5 98.7 332 42.5 347.5 99.2 333 42.5 352.5 98.8 335 37.5 2.5 98.7 336 37.5 7.5 98.6 337 37.5 12.5 98.0 338 37.5 17.5 99.0 339 37.5 22.5 98.0 361 37.5 132.5 99.3 362 37.5 137.5 99.0 363 37.5 142.5 99.1 364 37.5 147.5 98.9 365 37.5 152.5 98.8 366 37.5 157.5 99.2 367 37.5 162.5 99.0 368 37.5 167.5 98.9 369 37.5 172.5 98.5 370 37.5 177.5 99.1 371 37.5 182.5 98.8 372 37.5 187.5 99.1 373 37.5 192.5 99.5 374 37.5 197.5 99.7 375 37.5 202.5 99.0 376 37.5 207.5 99.5 377 37.5 212.5 99.0 378 37.5 217.5 99.2 379 37.5 222.5 99.6 380 37.5 227.5 98.8 381 37.5 232.5 98.8 382 37.5 237.5 99.1 391 37.5 282.5 99.5 392 37.5 287.5 99.7 393 37.5 292.5 99.0 394 37.5 297.5 99.2 395 37.5 302.5 99.2 396 37.5 307.5 99.0 397 37.5 312.5 99.2 398 37.5 317.5 99.1 399 37.5 322.5 99.2 400 37.5 327.5 98.8 401 37.5 332.5 98.6 402 37.5 337.5 98.3 403 37.5 342.5 98.5 404 37.5 347.5 98.0 405 37.5 352.5 98.8 406 37.5 357.5 98.5 411 32.5 22.5 97.5 412 32.5 27.5 97.7 431 32.5 122.5 99.7 432 32.5 127.5 99.1 433 32.5 132.5 99.7 434 32.5 137.5 99.4 435 32.5 142.5 98.9 436 32.5 147.5 99.2 437 32.5 152.5 98.2 438 32.5 157.5 98.5 439 32.5 162.5 99.0 440 32.5 167.5 99.1 441 32.5 172.5 99.0 442 32.5 177.5 99.2 443 32.5 182.5 99.1 444 32.5 187.5 98.8 445 32.5 192.5 98.6 446 32.5 197.5 99.0 447 32.5 202.5 99.0 448 32.5 207.5 99.1 449 32.5 212.5 99.0 450 32.5 217.5 99.3 451 32.5 222.5 99.3 452 32.5 227.5 98.8 453 32.5 232.5 99.1 454 32.5 237.5 99.0 455 32.5 242.5 98.3 462 32.5 277.5 100.0 463 32.5 282.5 99.5 464 32.5 287.5 98.8 465 32.5 292.5 98.4 466 32.5 297.5 98.8 467 32.5 302.5 98.9 468 32.5 307.5 99.5 469 32.5 312.5 98.2 470 32.5 317.5 98.8 471 32.5 322.5 98.7 472 32.5 327.5 98.8 473 32.5 332.5 98.1 475 32.5 342.5 97.4 476 32.5 347.5 97.6 503 27.5 122.5 99.6 504 27.5 127.5 99.6 505 27.5 132.5 99.5 506 27.5 137.5 99.2 507 27.5 142.5 98.7 509 27.5 152.5 98.2 510 27.5 157.5 99.1 511 27.5 162.5 98.8 512 27.5 167.5 98.7 513 27.5 172.5 99.5 514 27.5 177.5 99.0 515 27.5 182.5 98.6 516 27.5 187.5 98.8 517 27.5 192.5 99.3 518 27.5 197.5 97.5 519 27.5 202.5 98.1 520 27.5 207.5 98.8 521 27.5 212.5 99.0 522 27.5 217.5 99.1 523 27.5 222.5 99.5 532 27.5 267.5 99.6 533 27.5 272.5 99.1 534 27.5 277.5 98.7 535 27.5 282.5 98.4 536 27.5 287.5 98.1 537 27.5 292.5 98.8 538 27.5 297.5 97.8 539 27.5 302.5 98.3 540 27.5 307.5 97.6 541 27.5 312.5 97.3 542 27.5 317.5 98.0 547 27.5 342.5 97.1 573 22.5 112.5 99.8 574 22.5 117.5 99.7 575 22.5 122.5 99.0 576 22.5 127.5 99.8 577 22.5 132.5 99.3 578 22.5 137.5 99.0 579 22.5 142.5 99.3 587 22.5 182.5 97.6 588 22.5 187.5 98.2 591 22.5 202.5 99.5 592 22.5 207.5 98.7 605 22.5 272.5 95.9 606 22.5 277.5 98.0 608 22.5 287.5 98.1 609 22.5 292.5 98.8 644 17.5 107.5 99.8 645 17.5 112.5 98.6 646 17.5 117.5 98.3 647 17.5 122.5 97.4 648 17.5 127.5 98.7 649 17.5 132.5 99.1 650 17.5 137.5 98.6 651 17.5 142.5 98.1 678 17.5 277.5 97.1 716 12.5 107.5 98.4 717 12.5 112.5 98.6 720 12.5 127.5 98.7 721 12.5 132.5 98.3 750 12.5 277.5 97.7 782 7.5 77.5 98.7 783 7.5 82.5 97.5 784 7.5 87.5 98.7 785 7.5 92.5 98.1 786 7.5 97.5 98.5 788 7.5 107.5 99.7 789 7.5 112.5 98.0 822 7.5 277.5 96.8 839 2.5 2.5 98.6 856 2.5 87.5 98.0 858 2.5 97.5 98.1 859 2.5 102.5 98.3 860 2.5 107.5 99.3 868 2.5 147.5 99.5 869 2.5 152.5 99.2 892 2.5 267.5 99.7 893 2.5 272.5 98.8 894 2.5 277.5 98.5 902 2.5 317.5 97.9 905 2.5 332.5 98.5 927 -2.5 82.5 98.2 928 -2.5 87.5 97.0 941 -2.5 152.5 98.5 966 -2.5 277.5 98.6 981 -2.5 352.5 96.2 998 -7.5 77.5 97.8 1006 -7.5 117.5 99.3 1073 -12.5 92.5 98.6 1085 -12.5 152.5 98.5 1127 -17.5 2.5 97.6 1156 -17.5 147.5 98.8 1157 -17.5 152.5 97.9 1191 -17.5 322.5 98.3 1200 -22.5 7.5 98.5 1229 -22.5 152.5 97.8 1234 -22.5 177.5 98.5 1262 -22.5 317.5 99.3 1301 -27.5 152.5 99.2 1306 -27.5 177.5 99.0 1333 -27.5 312.5 99.3 1346 -32.5 17.5 97.6 1347 -32.5 22.5 98.0 1348 -32.5 27.5 98.8 1349 -32.5 32.5 99.6 1373 -32.5 152.5 98.4 1374 -32.5 157.5 97.5 1375 -32.5 162.5 98.5 1376 -32.5 167.5 99.0 1377 -32.5 172.5 99.3 1378 -32.5 177.5 99.1 1444 -37.5 147.5 97.9 1445 -37.5 152.5 99.0 1446 -37.5 157.5 98.9 1447 -37.5 162.5 99.0 1448 -37.5 167.5 99.1 1449 -37.5 172.5 99.0 1450 -37.5 177.5 98.9 1469 -37.5 272.5 98.1 1470 -37.5 277.5 98.3 1521 -42.5 172.5 98.6 1592 -47.5 167.5 99.4 1593 -47.5 172.5 99.4 1631 -52.5 5.0 99.4 1632 -52.5 15.0 99.6 1633 -52.5 25.0 100.0 1634 -52.5 35.0 100.0 1635 -52.5 45.0 99.8 1638 -52.5 75.0 99.8 1639 -52.5 85.0 99.4 1647 -52.5 165.0 98.7 1648 -52.5 175.0 99.5 1659 -52.5 285.0 99.2 1660 -52.5 295.0 96.3 1661 -52.5 305.0 98.3 1662 -52.5 315.0 99.8 1663 -52.5 325.0 99.4 1664 -52.5 335.0 99.8 1665 -52.5 345.0 100.0 1666 -52.5 355.0 99.5 1667 -57.5 5.0 99.4 1668 -57.5 15.0 99.6 1669 -57.5 25.0 99.7 1670 -57.5 35.0 99.8 1671 -57.5 45.0 99.7 1672 -57.5 55.0 99.9 1673 -57.5 65.0 99.7 1674 -57.5 75.0 100.0 1675 -57.5 85.0 99.7 1676 -57.5 95.0 99.8 1677 -57.5 105.0 99.5 1682 -57.5 155.0 99.2 1683 -57.5 165.0 99.2 1684 -57.5 175.0 99.4 1696 -57.5 295.0 98.8 1697 -57.5 305.0 99.3 1698 -57.5 315.0 99.5 1699 -57.5 325.0 99.6 1700 -57.5 335.0 99.2 1707 -62.5 45.0 99.7 1708 -62.5 55.0 100.0 1709 -62.5 65.0 99.4 1710 -62.5 75.0 99.5 1711 -62.5 85.0 99.8 1712 -62.5 95.0 99.3 1713 -62.5 105.0 99.9 1714 -62.5 115.0 98.9 1715 -62.5 125.0 99.5 1716 -62.5 135.0 99.7 1717 -62.5 145.0 99.6 1718 -62.5 155.0 99.8 1719 -62.5 165.0 99.8 1720 -62.5 175.0 99.0 1723 -62.5 205.0 99.8 1724 -62.5 215.0 99.6 1732 -62.5 295.0 99.3 1733 -62.5 305.0 99.5 1734 -62.5 315.0 99.7 1735 -62.5 325.0 100.0 1737 -62.5 345.0 98.8 1739 -67.5 5.0 98.6 1740 -67.5 15.0 99.3 1741 -67.5 25.0 99.0 1742 -67.5 35.0 98.6 1743 -67.5 45.0 98.6 1744 -67.5 55.0 99.6 1745 -67.5 65.0 99.6 1746 -67.5 75.0 99.5 1753 -67.5 145.0 99.7 1754 -67.5 155.0 99.6 1755 -67.5 165.0 99.5 1756 -67.5 175.0 99.7 1757 -67.5 185.0 99.5 1758 -67.5 195.0 99.7 1759 -67.5 205.0 99.5 1760 -67.5 215.0 100.0 1761 -67.5 225.0 99.5 1762 -67.5 235.0 100.0 1763 -67.5 245.0 99.8 1766 -67.5 275.0 99.5 1767 -67.5 285.0 100.0 1768 -67.5 295.0 99.2 1773 -67.5 345.0 98.6 1774 -67.5 355.0 99.5 1783 -72.5 170.0 99.4 1784 -72.5 190.0 99.8 1786 -72.5 230.0 100.0 1791 -72.5 330.0 99.0 1792 -72.5 350.0 99.5 1801 -77.5 170.0 98.2 1802 -77.5 190.0 99.7 1808 -77.5 310.0 97.8 1809 -77.5 330.0 98.7