water. In the station-climatology figure above, the plots for Point Barrow, Tiksi, Murmansk, and Isfjord are typical of land areas adjacent to seas that are ice-covered seasonally. The presence of the land allows temperatures to reach slightly more extreme values than the seas themselves. An essentially ice-free Arctic may be a reality in the month of September, anywhere from 2050 to 2100. Precipitation Precipitation in most of the Arctic falls only as rain and snow. Over most areas snow is the dominant, or only, form of precipitation in winter, while both rain and snow fall in summer (Serreze and Barry 2005). The main exception to this general description is the high part of the Greenland Ice Sheet, which receives all of its precipitation as snow, in all seasons. Accurate climatologies of precipitation amount are more difficult to compile for the Arctic than climatologies of other variables such as temperature and pressure. All variables are measured at relatively few stations in the Arctic, but precipitation observations are made more uncertain due to the difficulty in catching in a gauge all of the snow that falls. Typically some falling snow is kept from entering precipitation gauges by winds, causing an underreporting of precipitation amounts in regions that receive a large fraction of their precipitation as snowfall. Corrections are made to data to account for this uncaught precipitation, but they are not perfect and introduce some error into the climatologies (Serreze and Barry 2005). The observations that are available show that precipitation amounts vary by about a factor of 10 across the Arctic, with some parts of the Arctic Basin and Canadian Archipelago receiving less than of precipitation annually, and parts of southeast Greenland receiving over annually. Most regions receive less than annually. For comparison, annual precipitation averaged over the whole planet is about ; see Precipitation). Unless otherwise noted, all precipitation amounts given in this article are liquid-equivalent amounts, meaning that frozen precipitation is melted before it is measured. Arctic Basin The Arctic Basin is one of the driest parts of the Arctic. Most of the Basin receives less than of precipitation per year, qualifying it as a desert. Smaller regions of the Arctic Basin just north of Svalbard and the Taymyr Peninsula receive up to about per year. Monthly precipitation totals over most of the Arctic Basin average about from November through May, and rise to in July, August, and September.