SunkatTanning in Bali: how strong is the sun?
Bali is south of the equator, so its strongest sun comes in the Australian summer holidays. Month-by-month UV and burn times by skin type.
Short answer: you will tan fast and can burn in minutes. Bali's clear-sky midday UV is about 14 in December and January, and still about 10 in July, the dry-season peak for visitors. Fair skin can start to redden after about 11 minutes at a January midday.
UV index in Bali by month
Clear-sky UV index at midday near Kuta, Seminyak and Nusa Dua, with how long fair (type II) and medium (type III) skin take to start reddening without sunscreen at that peak. Peak months for Bali visitors are highlighted: December 14, January 14, June 9, July 10, August 12.
| Month | Midday UV clear sky | Fair skin first redness | Medium skin first redness | Typical cloud cover |
|---|---|---|---|---|
| January | 14 extreme | 11 min | 14 min | 98% |
| February | 15 extreme | 11 min | 13 min | 96% |
| March | 15 extreme | 11 min | 13 min | 92% |
| April | 13 extreme | 12 min | 15 min | 86% |
| May | 11 extreme | 15 min | 18 min | 70% |
| June | 9 very high | 18 min | 22 min | 65% |
| July | 10 very high | 16 min | 20 min | 65% |
| August | 12 extreme | 13 min | 16 min | 56% |
| September | 14 extreme | 11 min | 14 min | 66% |
| October | 15 extreme | 11 min | 13 min | 64% |
| November | 14 extreme | 11 min | 14 min | 93% |
| December | 14 extreme | 11 min | 14 min | 93% |
Midday UV is modelled from the sun's height and typical ozone for Bali (Madronich 2007), rounded. Haze and cloud make many real days 1 to 2 points lower. Cloud cover is the median for each month in 2023 to 2025 (Open-Meteo). Over the year the clear-sky peak runs from 9 to 15.
Southern-hemisphere sun
Bali is 8° south, so the sun is overhead around October and February and the UV is highest from October to March, the wet season. Cloud and showers cut the daily total, but the sun between them is extreme.
June to August is the dry season and the busiest time for Europeans. The UV is lower then, around 10 to 12 at a clear midday, but that is still at least a southern European summer.
For Australian visitors
Bali is much closer to the equator, so its January UV runs one to two points above Sydney's or Perth's, and in October and March it is several points higher. If you know your burn time at home at UV 12, expect to redden a little sooner in Bali.
Frequently asked
When is the sun strongest in Bali?
From October to March, with clear-sky midday UV of about 15.
Can you tan in Bali in July?
Yes. July's clear-sky midday UV is about 10, very high, so fair skin can start to redden after about 16 minutes at midday.
Going to Bali? Take your burn limit with you
Sunkat reads the live UV wherever you land and times each side for your skin type. Free on iPhone and Android.
