Peak sun hours in Massachusetts (2026)

Massachusetts averages 4.3 peak sun hours per day — 9% below the US average of 4.7. In practical terms, every 1 kW of solar there produces about 1,256 kWh of electricity a year.

Peak sun hours/day
4.3
Annual kWh per kW
1,256
vs US average
-9%

What this means for your system

To produce a given amount of electricity, you need fewer panels where there are more peak sun hours. At 4.3 hours, a typical home in Massachusetts needs a system sized to its usage and local sun — see exact numbers on the Massachusetts solar cost page or work it out with our sizing guide.

Peak sun hours by city in Massachusetts

Sunlight varies within Massachusetts. Here are city-level figures from multi-year irradiance data.

CityPeak sun hours/dayAnnual kWh per kW
Boston3.981,162
Worcester3.961,156

Peak sun hours in Massachusetts: FAQ

How many peak sun hours does Massachusetts get?
Massachusetts averages about 4.3 peak sun hours per day — 9% below the US average. That works out to roughly 1,256 kWh of electricity per year for every 1 kW of solar installed.
Is Massachusetts good for solar based on sunlight?
Sunlight is only part of the picture. Massachusetts's 4.3 peak sun hours are below average, so panels produce a little less, but your electricity rate and incentives matter just as much. See the full economics on our Massachusetts solar cost page.