Deconstruct Sun

Juneau, AK: Hardiness Zone 7a & Sunlight by Season

Juneau is in USDA hardiness zone 7a. Here’s what that means for winter, plus sunrise, sunset, daylight hours and the sun’s path through the year.

Hardiness zone
7a
2023 USDA map
Coldest winter night (avg)
0 to 5 °F
−17.8 to −15.0 °C
Longest day (Jun 21)
18h 17m
3:51 AM – 10:07 PM
Shortest day (Dec 21)
6h 22m
8:44 AM – 3:07 PM

Zone 7a in Juneau

On the 2023 USDA Plant Hardiness Zone Map, Juneau falls in zone 7a. That means the coldest night of a typical winter drops to between 0 and 5 °F. Perennials, shrubs and trees labeled for zone 7a or colder (a lower number) should survive the winter here. Parts of the area sit near the boundary with zone 6b, so a sheltered courtyard or an exposed hilltop can behave like the neighboring zone.

A zone only covers winter cold. For a plant to do well it also needs the right amount of sun, and that varies far more from one corner of a yard to the next than the zone does across town.

This is not the official USDA Plant Hardiness Zone Map. Zones are derived from the official 2023 dataset, resampled to about 2 km.

Nearby cities

All Alaska hardiness zones →

The sun over Juneau

On the June solstice the sun rises in the northeast at 3:51 AM and climbs to 55° above the horizon at 12:59 PM. On the December solstice the noon sun reaches only 8°, so a 20-foot tree casts a noon shadow about 135 feet long. In June the same tree’s noon shadow is only 14 feet.

0°15°30°45°60°75°90°NNEESESSWWNWN
June solsticeMarch & September equinoxDecember solstice

Open the interactive sun calculator for Juneau

Sunrise, sunset & daylight by month

DateSunriseSunsetDaylightNoon sun
Jan 218:23 AM3:55 PM7h 32m12°
Feb 217:13 AM5:09 PM9h 56m21°
Mar 216:55 AM7:14 PM12h 19m32°
Apr 215:29 AM8:25 PM14h 56m44°
May 214:19 AM9:30 PM17h 12m52°
Jun 213:51 AM10:07 PM18h 17m55°
Jul 214:27 AM9:39 PM17h 12m52°
Aug 215:33 AM8:26 PM14h 53m44°
Sep 216:40 AM6:59 PM12h 18m32°
Oct 217:47 AM5:35 PM9h 48m21°
Nov 217:59 AM3:26 PM7h 27m12°
Dec 218:44 AM3:07 PM6h 22m8°

Local time (Anchorage), including daylight saving time. “Noon sun” is the sun’s height above the horizon at solar noon.

Daylight through the year

0h6h12h18h24hJanuary: 7h 32mJanFebruary: 9h 56mFebMarch: 12h 19mMarApril: 14h 56mAprMay: 17h 12mMayJune: 18h 17mJunJuly: 17h 12mJulAugust: 14h 53mAugSeptember: 12h 18mSepOctober: 9h 48mOctNovember: 7h 27mNovDecember: 6h 22mDec

What “full sun” means in Juneau

Full sun is 6+ hours of direct sun. In Juneau an open spot has 18.3 hours of daylight to work with in June and 6.4 in December, so a bed that clears 6 hours in summer can easily drop to part shade in winter once the low sun slips behind trees and houses.

Full sun6+ hoursof direct sun
Part sun4–6 hoursof direct sun
Part shade2–4 hoursof direct sun
Full shadeUnder 2 hoursof direct sun

Measure the sun in your Juneau yard

Daylight is the ceiling. Deconstruct Sun traces the trees and buildings around one exact spot and tells you its real direct-sun hours, today and at every solstice and equinox.

Download on the App Store

Questions

What hardiness zone is Juneau, AK in?

Juneau, Alaska is in USDA plant hardiness zone 7a on the 2023 map. The average coldest winter night is 0 to 5 °F (−17.8 to −15.0 °C). It is near the boundary with zone 6b.

How many hours of daylight does Juneau get?

About 18.3 hours on the June solstice (sunrise 3:51 AM, sunset 10:07 PM) and 6.4 hours on the December solstice (sunrise 8:44 AM, sunset 3:07 PM). Around the equinoxes it is close to 12 hours.

How many hours of sun does my Juneau yard get?

Up to the daylight hours above, minus whatever trees, buildings and fences block. In winter, when the sun stays low, that can be most of it. The Deconstruct Sun iPhone app measures the real direct-sun hours for one exact spot by having you trace what is around it.

When is the best time to plant in Juneau?

Zone 7a tells you which perennials survive winter, not planting dates. For timing, use your local average frost dates from your county extension office, and choose plants rated for zone 7a or colder.

Source: USDA Plant Hardiness Zone Map, 2023. Agricultural Research Service, U.S. Department of Agriculture, planthardiness.ars.usda.gov. Underlying data © PRISM Group, Oregon State University, prism.oregonstate.edu, accessed 2026-08-30. Sun times calculated for 58.302, -134.420.