UV Index
UV Index
Today's UV index in Cát Bà, Vietnam 
will be up to 12.1, indicating a extreme level of sun exposure for the average person. Check our tips for today to make sure you're safe in the sun.
Last checked: 2025-06-01
UV index at 12.1 in Cát Bà means extreme risk: limit outdoor time especially from 10 a.m. to 4 p.m., actively seek shade, wear protective clothing, broad-brimmed hat, apply SPF 30+ sunscreen every 2 hours, and wear UV-blocking sunglasses. Watch for bright surfaces like water and snow increasing UV exposure.
The UV index in Cát Bà, Vietnam, tends to be high, especially from March to September, often ranging between 7 and 11, indicating strong sun exposure during these months.
Seasonal patterns show a hot and humid summer from May to September with heavy rain, while winter from November to February is cooler and drier, making spring and autumn the most pleasant times to visit.
Compared to the wider northern Vietnam region, Cát Bà experiences more humidity and frequent rain due to its coastal location. Neighboring countries like Laos and Cambodia typically have drier winters and less humidity overall.
See the UV index hour by hour for Cát Bà, along with the temperature and how cloudy it is. If the UV level is higher than moderate, it's best to avoid direct sunlight.