Summarize this article in one sentence.
If you’re not leaving for a few weeks or even months, find a list of average highs and lows for the time of year that you’re going to a particular place.  Search for averages on Wikipedia; the site lists average temperatures in the “Climate” section on most pages for countries, states, and provinces. You might also Google the weather in a given city. For example, you can search “average temperature in Chicago in April” to get results that will be helpful for choosing what to pack.   Check the specific forecast for each of the seven days that you’ll be gone. Many websites, like weather.com or AccuWeather, provide forecasts for anywhere in the world. Even though weather predictions are not always accurate, this is a good way to get a sense of what to expect. Reach out. If you are still unsure about what kind of weather to expect and thus what kind of clothing to pack, reach out to a friend, family member, or colleague who has visited your destination for pointers. Additionally, many major cities have travel or tourism bureaus.  Call or email one of these agencies to speak directly with a local and get their advice and pointers on what to expect and what kind of clothing to pack. If you can, wash your clothes during your trip (even if it's just a quick sink-wash and hanging the clothes out to dry) so that you have to pack even fewer items. If you won’t have access to laundry while you’re gone, you should plan to bring a change of clothes for each day of the week. Some hotels, for example, will provide complimentary toiletries such as shampoo, conditioner, and soap. Others will even provide a toothbrush and toothpaste. If so, that is at least a couple of items less that you have to worry about packing in your suitcase! Depending on your destination of choice, you may have to pack certain precautionary items or align your packing with the cultural sensitivities and traditions of your destination. Learn whether certain diseases are common in your destination. Consider, for example, malaria. If your destination has malaria-transmitting mosquitoes, you are at a significant risk of getting the disease, so take the necessary precautions. These may range from insect repellent to malaria prevention medicines. You can learn more about malaria and whether it is a concern in your destination by visiting the CDC website. This is especially useful if you are traveling abroad. Take into account security considerations, such as whether it is generally safe for somebody of your nationality to travel to your destination of choice at this time. If you currently live in the U.S., the Department of State website is the go-to site for this information. Consider whether there will be any important local holidays while you are there. Knowing this ahead of time will allow you to better prepare and not be taken by surprise should there be any major closures, crowds, or events. If you are traveling abroad, it is important to know how to communicate basic information. For this, you can use an app like Duolingo or free online materials.

Summary:
Check weather patterns in your destination city. Ask your accommodation(s) about laundry facilities. Find out whether your accommodation(s) will provide you with toiletries. Find out if there are any regional considerations you should take into account. Research the political, social, and cultural climate of your destination. Learn a few key words or phrases in the local language.