Weather & Seasons
UV & Heat Index Calculator
Equatorial UV peaks earlier than most tourists expect. "SPF 30 morning sun" doesn't exist in Malaysia — by 10am you're at UV 11+ on most days. This tool tells you safe hours by month, state and altitude.
Your conditions
Hour of day13:00
What this solves
"Malaysia is hot" is half the answer. The real story:
- UV 11+ is the daily norm at noon in lowland Malaysia — classified "extreme" by WHO.
- Cloudy days still burn. 80% UV gets through clouds.
- Heat index (felt temperature) is 5–10°C higher than air temp at 80%+ humidity.
- Cameron Highlands/Genting give cooler temps but UV is still intense at altitude.
- Sunscreen reapplication: every 2 hours, not once in the morning.
How to read results
- UV index: 0–2 low, 3–5 moderate, 6–7 high, 8–10 very high, 11+ extreme.
- Heat index: combines temperature + humidity. 32°C at 70% RH feels like 38°C.
- Safe hours: shaded time outside is the practical advice.
Limitations
- This is an estimate based on climatology. Real UV/heat index varies daily — check real-time apps.
- Skin type matters: fair-skinned (Fitzpatrick I-II) burns at UV 6+; darker skin tolerates UV 8-10.
- Haze can reduce UV but also traps heat — sometimes feels hotter.
FAQ
What SPF should I use?
SPF 30+ for most. SPF 50+ if fair-skinned or hiking. Reapply every 2 hours, more if swimming.
Is Cameron Highlands cooler?
Yes — typically 18–25°C day, 15–18°C night. But UV is still strong at altitude (every 1000m = +10% UV).
What is heat stroke vs heat exhaustion?
Heat exhaustion: heavy sweat, weakness, cold pulse. Heat stroke: hot dry skin, confusion, no sweat. Heat stroke is medical emergency.
Sources
- Malaysian Meteorological Department (METMalaysia) — UV readings
- WHO UV Index guidance
- NOAA Heat Index calculator