There are several ways to determine what to wear based on the weather forecast. Here are some options:

1. Daily Dress Me: This website breaks down the weather forecast into style inspiration that actually makes sense. All you need to do is type in your city, and it will provide you with a five-day forecast that includes clothing suggestions.

2. Weather Fit: This iOS app provides clothing suggestions based on the weather forecast. It has a cute little character who dresses according to the weather, and the app shows you what to wear now, today, tonight, and tomorrow. It also provides hourly forecasts, current conditions, daily forecasts, and next-hour precipitation at a glance.

3. Clothes Forecast: This website provides information on appropriate clothes to pack and wear according to temperature for your travel destinations. It offers links to cities in various countries and provides information on what you need to know about appropriate clothes in your destinations.

4. How to Style: This website provides clothing suggestions based on different weather conditions. For example, if its going to be hot tomorrow, it suggests wearing lightweight, breathable clothing such as cotton or linen, and choosing lighter colors to reflect the suns rays. If its going to be rainy, it suggests wearing waterproof or water-resistant clothing such as a raincoat or jacket, and choosing shoes that are also waterproof.

In summary, there are several resources available to help you determine what to wear based on the weather forecast. You can use websites like Daily Dress Me or Clothes Forecast, or apps like Weather Fit. Additionally, websites like How to Style provide clothing suggestions based on different weather conditions.