Contour Lines: Contour lines are used to determine elevations and are lines on a map that are produced from connecting points of equal elevation (elevation refers to height in feet, or meters, above sea level). profile may be constructed quickly and accurately across any straight line on a map by following this procedure: a. Lay a strip of paper along a line across the area where the profile is to be constructed. b. Mark on the paper the exact place where each contour, stream and hill top crosses the profile line.
During may you will find snow at the North and South pole. It will also snow in high lying areas such as some mountains. Many people forget that while in May that while the Northern Hemisphere is experiencing spring (which in some places means there is still snow), the Southern Hemisphere is experiencing winter.
Yes there may be, but generally snow in central London is uncommon in winter. Although the days will be lengthening from January there is always the potential for clear, cold and windy days, perhaps with a bit of snow, through the end of February and to early March.