The climate of Bihar is sub-tropical monsoonal. Seasonal variations occur mainly in the form of three distinct seasons - summers, winters and monsoons. Therefore, the climate and weather largely determine the kind of clothing you need to carry on your visit to the place.
In case, you are Bihar-bound during summers (April, May and June); remember that the mercury level may go up to even 45oC in most of the places of the state. Therefore, it is advisable that you carry light cotton clothing and clothes made of natural fabrics with you. Synthetic clothes and clingy fabrics preferably be avoided. Go for loose and airy clothes that regulate airflow in the body. Opt for clothes in lighter shades and avoid loud colors.
Monsoon season in the state stretches for a long period and generally lasts from June to September. If you happen to visit the state during this season of showers, i.e. in monsoons, remember that most of the cities here experience high levels of humidity apart from the frequent spells of monsoon rain. Therefore, wear loose and breathable fabrics, instead of tight-fitting clothes. At the same time, carry waterproof clothing that comes quite handy while taking monsoon strolls.
Winters are very pleasant and favorable from the vacationing point of view. In fact, it is the best time to visit the state. It lasts from November to February and the place beckons many tourists during this period. Winters can be moderate to quite severe in Bihar. It is advisable to carry warm woolen clothes while traveling in Bihar during winter months
Apart from the seasonal demands on clothing, certain other things need to be considered while dressing up. Even though you can easily stick to western wear and other contemporary clothes in the place, carrying a few pair of ethnic or Indian dresses is advisable.