The 40th parallel north is a circle of latitude that is 40 degrees north of the Earth's equatorial plane. It crosses Europe, the Mediterranean Sea, Asia, the Pacific Ocean, North America, and the Atlantic Ocean. At this latitude the sun is visible for 15 hours, 1 minute and 28 seconds during the summer solstice and 9 hours, 20 minutes during the winter solstice. On 21 June, the maximum altitude of the sun is 73.44 degrees, while it's 26.56 degrees on 21 December. The maximum altitude of the Sun is > 35.00º in October and > 28.00º in November. The 40th parallel north is the southern baseline for Canada's National Topographic System.

Around the world

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Notable cities and towns on 40°N

United States

The parallel 40° north formed the boundary between the Kansas and Nebraska territories, as per the Kansas–Nebraska Act of 1854. It remains the boundary between the modern states of Kansas and Nebraska. The parallel 40° north formed the original northern boundary of the British Colony of Maryland. A subsequent royal grant gave the Colony of Pennsylvania land north of the 40th parallel but mistakenly assumed it would intersect the Twelve Mile Circle, which it does not. Pennsylvania's border was thus unclear and the colony pushed for a border far south of the 40th parallel. The Mason–Dixon Line was drawn between 1763 and 1767 as the compromise boundary between the overlapping claims of these two colonies. The parallel 40° north passes through the cities of Philadelphia, Pennsylvania, Boulder, Colorado, and Columbus, Ohio; as well as northern suburbs of Indianapolis, Indiana and the southern suburbs of Pittsburgh, Pennsylvania. The parallel goes directly through the John Glenn Columbus International Airport, with runway 10L-28R lying immediately north of the line, runway 10R-28L lying slightly south of it, and the line going through the northernmost edges of the terminal. It also passes through the main campus of The Ohio State University; specifically, it cuts directly across the Oval greenspace, between University Hall and the William Oxley Thompson Memorial Library. Ohio Stadium, one of the largest stadiums in the world, barely misses the parallel 40° north (6 seconds or 185 m above 40° north). Baseline Road in Boulder, Colorado, traces the parallel 40° north. Thistle, Utah, a ghost town since 1983, is slightly (30 seconds or 956 m) below 40° north.

Japan

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