Peak Sun Hours in Long Beach, California, United States
- Solar zone
- Zone 4 (excellent)
- Best month
- May (6.5)
- Worst month
- December (2.8)
- Climate
- Temperate · 17.3°C
Monthly solar breakdown
| Month | GHI | Clear-sky | DNI | DHI | Temp °C | Humid % |
|---|---|---|---|---|---|---|
| Jan | 3.14 | 3.78 | 4.89 | 1.12 | 12.0 | 59 |
| Feb | 4.01 | 4.87 | 5.24 | 1.46 | 12.2 | 63 |
| Mar | 5.17 | 6.26 | 5.76 | 1.87 | 13.8 | 64 |
| Apr | 6.32 | 7.49 | 6.47 | 2.18 | 15.1 | 63 |
| May | 6.55 | 8.23 | 5.91 | 2.50 | 17.5 | 62 |
| Jun | 6.29 | 8.53 | 4.89 | 2.79 | 20.4 | 57 |
| Jul | 6.55 | 8.18 | 5.45 | 2.71 | 23.4 | 52 |
| Aug | 6.34 | 7.57 | 5.87 | 2.37 | 23.9 | 49 |
| Sep | 5.47 | 6.49 | 5.80 | 1.88 | 23.0 | 50 |
| Oct | 4.31 | 5.19 | 5.40 | 1.47 | 19.5 | 52 |
| Nov | 3.40 | 4.01 | 5.20 | 1.15 | 15.5 | 53 |
| Dec | 2.83 | 3.43 | 4.65 | 1.01 | 11.8 | 58 |
GHI, Clear-sky, DNI, DHI in kWh/m²/day. Data: NASA POWER climatology (long-term monthly averages).
Off-grid calculator
Add appliances
- Add an appliance to size a system.
Sizing
- Daily load
- 0.00 kWh
- Panel wattage
- 0 W
- Panel count (400W modules)
- 0
- Battery bank
- 0.0 kWh
Sizing against worst-month PSH of 2.83 kWh/m²/day, 0.77 system efficiency.
About solar in Long Beach
Long Beach, United States has a temperate climate with meaningful seasonal variation in solar resource. Its annual peak sun hours average 5.03 kWh/m²/day, a excellent solar resource by global standards.
The strongest month in Long Beach is May (spring) at 6.55 kWh/m²/day, and the weakest is December (winter) at 2.83 kWh/m²/day. When sizing a year-round off-grid system, it's standard practice to design against the December value rather than the annual average — otherwise the battery bank runs low during the darkest weeks.
Long Beach's solar conditions are well within the range where off-grid PV is a straightforward engineering exercise with standard-sized arrays and lithium batteries.
FAQ
- What are the peak sun hours in Long Beach?
- Long Beach averages 5.03 peak sun hours per day annually, ranging from 2.83 in December to 6.55 in May.
- How many solar panels do I need in Long Beach?
- Panel count depends on your daily load. At Long Beach's annual average of 5.03 kWh/m²/day, a 5 kWh/day load needs roughly 4 × 400 W panels. Use the calculator above for your actual load.
- What size battery do I need in Long Beach?
- Sizing against Long Beach's worst month (December, 2.83 kWh/m²/day) with 2 days of autonomy at 80% depth of discharge, a 5 kWh/day load needs about a 12.5 kWh battery bank.
- How does Long Beach's solar resource compare globally?
- Long Beach sits in solar zone 4 out of 5 (where 5 is strongest) at 5.03 kWh/m²/day — excellent by global standards. For reference, top-tier desert sites average ~6.5 and high-latitude cities around 2.5 kWh/m²/day.
- How much does winter reduce solar output in Long Beach?
- Long Beach's worst month (December) delivers 2.83 kWh/m²/day — about 43% of the summer peak of 6.55. Off-grid systems here typically oversize 1.5–2× or pair with a backup source.
- Do cloudy days significantly affect Long Beach's solar?
- Partly. Diffuse light still produces 10–25% of clear-sky output. Long Beach's 5.03 kWh/m²/day already reflects average cloudiness, so no further derating is needed for sizing.
- What panel tilt works best in Long Beach?
- At Long Beach's latitude (34°), a fixed tilt near 34° balances year-round yield. Winter-heavy loads favor latitude + 15°; summer-heavy, latitude − 15°.