What is the best angle for solar panels in winter?
About your latitude plus 15°: at 40° north that is 55° from horizontal, facing true south — compared with 25° in summer.
How to work it out
- Winter: latitude 40° + 15° = 55° from horizontal
- Height to raise the top edge = panel length × sin(55°) → 9.8 in per foot · 24.6 cm per 30 cm of panel
In winter the midday sun sits low in the southern sky, so a steeper panel faces it more squarely. For off-grid systems winter is usually the season that sets the size of everything, so getting this angle right is worth a bracket adjustment.
Adjust for your project
- Face the panels
- True south (not magnetic south)
- Winter angle
- 55°
- Summer angle
- 25°
- Rise per foot (or per 30 cm) of panel length
- 9.8 in per foot · 24.6 cm per 30 cm of panel
Angles at other latitudes
| Latitude | Tilt from horizontal | Winter angle | Summer angle |
|---|---|---|---|
| 25° | 40° | 40° | 10° |
| 30° | 45° | 45° | 15° |
| 35° | 50° | 50° | 20° |
| 40° | 55° | 55° | 25° |
| 45° | 60° | 60° | 30° |
| 50° | 65° | 65° | 35° |
What to know about winter panel angles
- Winter output is the bottleneck. In Chicago, PVWatts shows a latitude-tilted panel’s lowest month at about 2.7 peak sun hours against 4.5 for the year; in Seattle, about 1.6 against 3.8.
- Steeper sheds snow. At 55° or more, snow slides off far sooner than from a nearly flat panel.
- Cloudy winters change the sum. Under heavy overcast, light comes from the whole sky, and the angle matters less. In grey climates the gain from going steeper is smaller than in clear ones.
- Adjust twice a year. A simple routine with an adjustable mount is to change it around the equinoxes: steep for the darker half of the year, flatter for the brighter half.
At this angle, a 100 W panel’s winter output is what sets an off-grid system — see how much power a 100W solar panel produces per day with your winter sun hours, and how many solar panels for a small cabin for a winter sizing example.
Different size? Use the full Solar Panel Tilt Angle Calculator.
What you’ll need
- Adjustable tilt mount bracketsBudget price
Lets you change a ground- or roof-mounted panel’s angle with the seasons instead of leaving it flat.
See options on Amazon (opens in a new tab) - Digital angle finderBudget price
Sits on the panel frame and reads its tilt to a tenth of a degree, so a seasonal adjustment actually lands on the angle you worked out.
See options on Amazon (opens in a new tab)
As an Amazon Associate we earn from qualifying purchases. Links to products are affiliate links — they cost you nothing extra and help keep these calculators free.
Frequently asked questions
What is the best winter angle for solar panels at 30° latitude?
About 45°.
What is the best winter angle for solar panels at 47° latitude (Seattle)?
About 63°.
What is the best summer angle for solar panels at 40° latitude?
About 25°.
Sources
- National Laboratory of the Rockies (formerly NREL) — PVWatts® Calculator (opens in a new tab) — Look up the solar resource (peak sun hours) and yearly output for your own address; default system losses 14%.
- NLR (formerly NREL) — PVWatts® v8 API, NSRDB PSM V3 TMY data (opens in a new tab) — City figures on this site: fixed open-rack array facing due south, tilted at the site’s latitude, 14% system losses, queried October 2026.