Choosing a tarp or tent face for the morning sun, by season and latitude

The sun rises at a different point on the horizon through the year. Near the June solstice at 40° N it rises north of east, and near the December solstice it rises south of east. The bearing depends on the date and on the latitude, so one figure for a whole country is not enough. The table below gives the sunrise and sunset bearings at seven latitudes from 0° to 60° N, and the sections that follow show how to use them for a tent door or a tarp’s open end.

Sunrise bearing follows the sun’s declination

The sun’s declination is its angle north or south of the celestial equator. It is +23.44° at the June solstice and −23.44° at the December solstice. For a simple geometric sunrise, the bearing from true north is set by the declination and the latitude:

cos(sunrise azimuth) = sin(declination) ÷ cos(latitude)

40° N, 21 June, declination +23.44°:
sin 23.44° = 0.3978
cos 40°    = 0.7660
0.3978 ÷ 0.7660 = 0.5193
arccos 0.5193 = 58.7°           sunrise bearing
360° − 58.7° = 301.3°           sunset bearing

The azimuth is measured clockwise from true north, as NOAA’s solar calculator defines it. The figure ignores refraction, so it is slightly different from what the Sun & daylight tool reports for the same day. The sunset guide explains the refraction allowance and how it moves the sunset time.

Sunrise and sunset bearings by latitude

The table gives the bearings for the June and December solstices at each latitude, using the same formula. The sunset bearing is 360° minus the sunrise bearing.

Read a row across to see how far the sunrise moves between seasons. At 40° N the sunrise moves from 58.7° in June to 121.3° in December, a difference of 62.6°. At 60° N the same change is 105.4°, because the sun rises further from east at higher latitudes in summer.

Equinoxes and the dates between

On the equinoxes the sun’s declination is close to zero, so sin(declination) is close to zero and the simple formula gives a bearing close to 90°. The sun therefore rises close to due east at every latitude away from the poles. For any other date, use the sun’s declination for that day in the same formula, or read the bearing from the tool for that date. The solstice rows are the extremes of the year, not a set of values for every day.

Near the poles the bearing is less useful. At high latitudes the sun can stay above or below the horizon for days, and a bearing from the table may not apply at all. Check the tool for the dates you need.

Southern hemisphere campsites

The sunrise bearing follows the declination on the date, not the hemisphere. On 21 June the sun is north of the celestial equator, so it rises north of east in both hemispheres. The December figures apply to southern summer, when the sun is to the south of the equator, and it rises south of east. The table is written for northern latitudes, so for a southern site read the December column for summer and the June column for winter.

The Sun & daylight tool confirms the pattern. At 34° S, 151.2° E, it gives a sunrise bearing of 61.9° on 21 June 2026, and 119.2° on 21 December 2026. Those values sit near the 30° row of the table, because 34° is close to 30°, and the small remaining difference comes from the refraction allowance and the day’s declination.

Shadows and the open end of a tarp

A shadow points 180° away from the sun. If the sun bears 60°, shadows fall on a bearing of 240°. At sunrise the shadows of trees and tent poles are long and point back towards the west.

The open end of an A-frame tarp faces along the ridge, not across it. The ridge bearing you enter in the shelter tool therefore gives the direction of both open ends, one at the ridge bearing and one at its reverse.

sunrise bearing, 40° N, 21 June     58.7°
ridge bearing (open end faces)      60°
difference                           1.3°
reverse end faces                  240°

The open end at 60° faces 1.3° from the sunrise point, so on a flat horizon
the first direct light on the morning of 21 June arrives through that end.

Whether morning light through the open end suits you depends on the weather and on the wind. A door that faces the sunrise gets the early light, and a door that faces away from it stays in shade for longer. The A-frame tarp geometry guide sets out the shape that determines where the open end sits.

Horizon obstructions change the first light

The table assumes a clear, flat horizon. A ridge or a line of trees to the east hides the sun later than the table suggests, and the first direct light may not reach the camp until well after sunrise. The Sun & daylight tool has a horizon input from 0° to 20° that subtracts an obstruction angle from the sunrise and sunset times. Enter the angle that matches the skyline you will see.

Choose the campsite with the skyline in mind, not only the bearing. The choosing a campsite guide covers the ground, water and overhead hazards that come first, and the true north and declination guide explains how to take a bearing from a compass or map before you enter it into the tool.

Checking the sun with the tool

The Sun & daylight tool shows the sun’s bearing for any time you enter, in UTC. The link below sets 11:32 UTC on 21 June 2026 for 40° N and 105.27° W. At that time the tool reads a sun bearing of 57.9° and an elevation of −0.8°, which is the sunrise point. Convert the time to local clock time with the place’s UTC offset; these coordinates are Boulder, Colorado, on Mountain Daylight Time (UTC−6) in June, so 11:32 UTC is 05:32 local.

Check sunrise in Sun & daylight