Solar Sunlight Hours in Thailand: Your Monthly Peak Sun Guide
Understanding sunlight patterns is the first step to estimating your solar system's performance. Thailand's tropical climate delivers excellent solar potential year-round.
Why Thailand Is Ideal for Solar Energy
Thailand sits between 5°N and 20°N latitude, placing it in one of the world's best solar zones. The country receives abundant sunshine throughout the year, with only minor variations during the monsoon season.
- ✓ High irradiance: 4.5–6.5 kWh/m²/day across most regions
- ✓ Consistent sunshine: Even rainy months average 3–4 peak hours
- ✓ Hot climate advantage: Higher temperatures slightly reduce efficiency, but longer days compensate
Monthly Peak Sun Hours by Region
| Month | Bangkok (Central) | Chiang Mai (North) | Udon Thani (NE) | Phuket (South) | Trat (East) |
|---|---|---|---|---|---|
| Jan | 6.2 | 6.0 | 6.3 | 6.5 | 6.1 |
| Feb | 6.5 | 6.3 | 6.5 | 6.8 | 6.4 |
| Mar | 6.3 | 6.1 | 6.4 | 6.5 | 6.2 |
| Apr | 6.0 | 5.8 | 6.1 | 5.8 | 5.9 |
| May | 5.2 | 5.0 | 5.3 | 5.0 | 5.1 |
| Jun | 4.8 | 4.6 | 4.9 | 4.5 | 4.7 |
| Jul | 4.5 | 4.3 | 4.6 | 4.2 | 4.4 |
| Aug | 4.6 | 4.4 | 4.7 | 4.3 | 4.5 |
| Sep | 5.0 | 4.8 | 5.1 | 4.8 | 4.9 |
| Oct | 5.5 | 5.3 | 5.6 | 5.2 | 5.4 |
| Nov | 6.0 | 5.8 | 6.1 | 5.8 | 5.9 |
| Dec | 6.1 | 5.9 | 6.2 | 6.0 | 6.0 |
Values represent average daily peak sun hours (kWh/m²/day). Data sourced from NASA satellite measurements.
What Does This Mean for Your Solar System?
Peak sun hours tell you how much energy your panels can generate. A 5 kW system in Bangkok produces roughly:
Best Months for Solar Installation
While solar works year-round, November to February offer the highest output in most regions. Installing during the rainy season (May–October) means your system is ready to capture maximum energy when the dry season begins.
How Sunlight Hours Affect System Sizing
A home in Phuket (6.5 peak hours) needs fewer panels than the same home in Chiang Mai (6.0 hours) to produce the same energy. When sizing your system, installers calculate using your monthly electricity bill and local peak sun data.
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