Peak Sun Hours in Mumbai, Maharashtra, India
- Solar zone
- Zone 4 (excellent)
- Best month
- May (7.1)
- Worst month
- July (3.8)
- Climate
- Tropical · 26.8°C
Monthly solar breakdown
| Month | GHI | Clear-sky | DNI | DHI | Temp °C | Humid % |
|---|---|---|---|---|---|---|
| Jan | 4.88 | 5.05 | 5.21 | 1.68 | 23.2 | 51 |
| Feb | 5.74 | 5.89 | 5.77 | 1.80 | 25.7 | 44 |
| Mar | 6.59 | 6.76 | 6.03 | 2.04 | 28.7 | 45 |
| Apr | 7.08 | 7.28 | 5.86 | 2.35 | 30.7 | 53 |
| May | 7.09 | 7.42 | 5.46 | 2.58 | 31.2 | 60 |
| Jun | 5.00 | 6.97 | 2.25 | 2.61 | 28.7 | 80 |
| Jul | 3.79 | 6.62 | 0.77 | 2.41 | 26.6 | 90 |
| Aug | 4.04 | 6.51 | 1.08 | 2.46 | 26.1 | 90 |
| Sep | 4.78 | 6.25 | 2.38 | 2.44 | 26.2 | 89 |
| Oct | 5.21 | 5.70 | 4.07 | 2.14 | 26.2 | 78 |
| Nov | 4.84 | 5.05 | 4.80 | 1.74 | 24.6 | 69 |
| Dec | 4.53 | 4.73 | 4.96 | 1.59 | 23.3 | 60 |
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 3.79 kWh/m²/day, 0.77 system efficiency.
About solar in Mumbai
Mumbai, India has a warm, tropical climate with a distinct wet and dry season. Its annual peak sun hours average 5.3 kWh/m²/day, a excellent solar resource by global standards.
The strongest month in Mumbai is May (spring) at 7.09 kWh/m²/day, and the weakest is July (summer) at 3.79 kWh/m²/day. When sizing a year-round off-grid system, it's standard practice to design against the July value rather than the annual average — otherwise the battery bank runs low during the darkest weeks.
Mumbai'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 Mumbai?
- Mumbai averages 5.3 peak sun hours per day annually, ranging from 3.79 in July to 7.09 in May.
- How many solar panels do I need in Mumbai?
- Panel count depends on your daily load. At Mumbai's annual average of 5.3 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 Mumbai?
- Sizing against Mumbai's worst month (July, 3.79 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 Mumbai's solar resource compare globally?
- Mumbai sits in solar zone 4 out of 5 (where 5 is strongest) at 5.3 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 does the wet season affect solar generation in Mumbai?
- Mumbai's dry-season output peaks at 7.09 kWh/m²/day in May; the wet season drops it to 3.79 in July. That ~62% swing is a key sizing consideration.
- Can solar panels survive tropical storms in Mumbai?
- Most tier-1 PV panels are rated for 140+ mph wind loads; mounting hardware usually fails first. In cyclone-prone regions like India, specify IEC 61215-certified panels and anchor-bolt mounts rather than ballasted.
- What's the dry-to-wet output gap in Mumbai?
- Mumbai swings from 7.09 kWh/m²/day in May (dry) to 3.79 in July (wet) — roughly 62%. Year-round off-grid systems must size against the wet-season minimum.