Cities on the same latitude

Worked example: Denver's parallel

The band runs from 39.489° N to 39.989° N. The largest US towns in it are Columbus, OH; Indianapolis, IN; Denver, CO; Aurora, CO; Reno, NV.

Outside the US, the world cities in the band, west to east:

• Ankara, Turkey (39.93° N), 6,325 miles from Denver
• Bukhara, Uzbekistan (39.78° N), 6,902 miles from Denver
• Samarkand, Uzbekistan (39.67° N), 6,927 miles from Denver
• Jiayuguan, China (39.82° N), 6,747 miles from Denver
• Beijing, China (39.90° N), 6,347 miles from Denver

What counts as the same latitude

No two towns sit on exactly the same parallel, so the tool uses a band a quarter degree either side of your point. A quarter degree of latitude is about 17.2 miles, so the band is roughly 34 miles tall from north to south and wraps the whole globe.

US places come from the Census list of 10,255 incorporated places with 1,000 or more residents. World cities come from the Natural Earth 1:50m populated places file, which lists 1,172 cities chosen for map labeling, so smaller foreign towns are not included.

Reading the strip and the tables

The strip is the whole parallel from 180° west to 180° east. It is stretched vertically so the dots inside the half degree band separate. Blue dots are world cities, small ink dots are US towns, and the orange dot is your place.

Tables run west to east. The longitude gap is how far east or west each place is from you in degrees. The distance is the straight great-circle distance, which is shorter than walking along the parallel because a parallel is not a great circle, except at the equator.

Same latitude, different climate

Sharing a parallel means the same sun angle and the same day length through the year, not the same weather. Ocean currents, elevation, and distance from the sea change temperature and rainfall a great deal, so two towns on one parallel can have very different climates. Use the list for geography, travel ideas, and classroom comparisons. Southern Hemisphere places never appear in the band for a northern point; to see the mirror parallel, enter the same latitude with a minus sign.

How long is your parallel?

A parallel is a full circle around the Earth. At Denver's latitude it is 19,175 miles long on the WGS84 ellipsoid, against 24,901 miles for the equator. Every degree of longitude along it is 53.26 miles, so two places 10 degrees apart on this parallel are about 533 miles apart if you follow the parallel itself.

The great-circle distance in the tables is shorter than that. Following a parallel means holding a constant east or west heading, which is a rhumb line, and rhumb lines are longer than great circles except on the equator.