Something to always keep in mind when heading to another country is that the local customs on attire may well be different from that which you have come to know in your own locale. This is especially important when you are a person coming from a fairly liberal country from, say, the West, and are headed to an Islamic country in the Middle East. To that end, here is a guide of what to wear in Oman if you are not certain of what clothes to pack for your stay.
The first thing to note about Oman is that as far as Islamic countries go, it is relatively liberal. Headscarves for women are not obligatory for tourists and some modes of western dress, such as t-shirts with denim jeans, are actually seen fairly often in the big cities. That having been said, this is still more or less an Islamic culture in which you are going to be immersing yourself, and thus it is always better to err on the side of conservatism whenever in doubt. For example, while you may certainly wear somewhat fitting (note the “somewhat”, which means stay away from anything you can describe as “skin-tight”) trousers, you are nevertheless advised to spurn the knee-length cut-off trousers and shorts in your wardrobe.
Balance is ideal when you are travelling in Oman and planning your wardrobe. Whenever you are in public, you have to make sure-whether you are a man or a woman-that your bottoms cover your legs and your shoulders. Yet if you are in one of the big cities and are in a club or some similar establishment serving alcoholic drinks, you are allowed to show a little more skin and even wear a modern skirt. Notice that you are allowed to do this “in the club” and not outside of it: you should cover yourself prior to entering the establishment, in other words. One has to think of it as one would think of preparing for the beach: Omani beaches do see people in swimsuits (though not terrifically revealing, flimsy ones), yet Omani roads do not. Omani mosques see women donning veils and headscarves for entry, yet Omani shopping malls rarely see the same. Hence, ensure that your clothes fit the location, with all general locations being places where modesty is the norm. Violate this basic rule and you shall most likely be in for a bit of trouble, with less respectful treatment being given to you whether you are male or female.
The climate of the country is best described as perpetually sweltering, especially if you are someone coming from cooler climes. As such, the injunction to cover as much of your skin as possible is not just based on the local preference for conservatism. Sunburn, sunstroke, and dehydration are all possibilities if you do not keep this in mind-and with peak temperatures of over 100 degrees Fahrenheit in June and July, this is not at all surprising. Cotton is also the norm for fabrics, so look for it and similarly lightweight textiles when looking for what to wear in Oman.