Singapore is generally very relaxed regarding everyday clothing due to the intense tropical heat, but it is exceptionally strict when visiting religious or official sites. In 2026, you will see locals wearing T-shirts, shorts, and flip-flops in malls and on the MRT. However, if you plan to enter a mosque, Hindu temple, or Buddhist temple, you must have your shoulders and knees covered; many sites will provide a sarong or robe at the entrance if you are underdressed. For high-end dining and "rooftop bars" in the Central Business District (like Cé La Vi), there is often a "smart casual" dress code that prohibits flip-flops and singlets for men. Additionally, while there are no laws against revealing clothing in public, "modesty" is a cultural value, and extremely skimpy beachwear is considered inappropriate outside of Sentosa Island. Essentially, as long as you carry a light scarf or "cover-up" for temples and avoid "offensive" graphics on your shirts, you will have no issues with Singapore's dress standards.