Peak Sun Hours in Rio de Janeiro, Rio de Janeiro, Brazil
- Solar zone
- Zone 3 (good)
- Best month
- February (6.0)
- Worst month
- June (3.5)
- Climate
- Tropical · 23.4°C
Monthly solar breakdown
| Month | GHI | Clear-sky | DNI | DHI | Temp °C | Humid % |
|---|---|---|---|---|---|---|
| Jan | 5.78 | 8.19 | 3.84 | 2.60 | 25.7 | 83 |
| Feb | 5.97 | 7.77 | 4.60 | 2.34 | 25.8 | 82 |
| Mar | 5.14 | 6.88 | 4.03 | 2.18 | 25.4 | 83 |
| Apr | 4.52 | 5.80 | 4.42 | 1.69 | 24.3 | 82 |
| May | 3.68 | 4.82 | 4.06 | 1.46 | 22.3 | 80 |
| Jun | 3.46 | 4.33 | 4.30 | 1.24 | 21.5 | 80 |
| Jul | 3.64 | 4.59 | 4.63 | 1.16 | 20.9 | 78 |
| Aug | 4.26 | 5.41 | 4.89 | 1.33 | 21.3 | 77 |
| Sep | 4.57 | 6.29 | 4.20 | 1.66 | 22.0 | 77 |
| Oct | 5.00 | 7.32 | 3.62 | 2.19 | 22.9 | 79 |
| Nov | 5.05 | 8.00 | 3.06 | 2.53 | 23.4 | 82 |
| Dec | 5.56 | 8.23 | 3.52 | 2.61 | 24.7 | 84 |
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 3.46 kWh/m²/day, 0.77 system efficiency.
About solar in Rio de Janeiro
Rio de Janeiro, Brazil has a warm, tropical climate with a distinct wet and dry season. Its annual peak sun hours average 4.72 kWh/m²/day, a good solar resource by global standards.
The strongest month in Rio de Janeiro is February (summer) at 5.97 kWh/m²/day, and the weakest is June (winter) at 3.46 kWh/m²/day. When sizing a year-round off-grid system, it's standard practice to design against the June value rather than the annual average — otherwise the battery bank runs low during the darkest weeks.
Rio de Janeiro'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 Rio de Janeiro?
- Rio de Janeiro averages 4.72 peak sun hours per day annually, ranging from 3.46 in June to 5.97 in February.
- How many solar panels do I need in Rio de Janeiro?
- Panel count depends on your daily load. At Rio de Janeiro's annual average of 4.72 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 Rio de Janeiro?
- Sizing against Rio de Janeiro's worst month (June, 3.46 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 Rio de Janeiro's solar resource compare globally?
- Rio de Janeiro sits in solar zone 3 out of 5 (where 5 is strongest) at 4.72 kWh/m²/day — good by global standards. For reference, top-tier desert sites average ~6.5 and high-latitude cities around 2.5 kWh/m²/day.
- How does the wet season affect solar generation in Rio de Janeiro?
- Rio de Janeiro's dry-season output peaks at 5.97 kWh/m²/day in February; the wet season drops it to 3.46 in June. That ~53% swing is a key sizing consideration.
- Can solar panels survive tropical storms in Rio de Janeiro?
- Most tier-1 PV panels are rated for 140+ mph wind loads; mounting hardware usually fails first. In cyclone-prone regions like Brazil, specify IEC 61215-certified panels and anchor-bolt mounts rather than ballasted.
- What's the dry-to-wet output gap in Rio de Janeiro?
- Rio de Janeiro swings from 5.97 kWh/m²/day in February (dry) to 3.46 in June (wet) — roughly 53%. Year-round off-grid systems must size against the wet-season minimum.