If you have used the new Yahoo Weather app for any amount of time, then you've seen the beautiful photos it displays to match a location, time of day, and current conditions. If you have a Flickr account, you can add your own photos to be considered for the app. And you can upload directly from your iPhone, using the Flickr app. Here's how:

Launch the Flickr app and tap the More button (the one with the blue and pink dots) in the lower-right corner.
Next, tap Search. From the Search screen, tap the Groups button below the search box and then search for Project Weather. Tap the Project Weather result and then tap the blue Join button. Now that you are a member of this group, you can submit photos for approval for use with the Yahoo Weather app.
Return to the home screen of the Flickr app and snap a photo with the app or select one from your library. Flickr has a few guidelines, which if you follow them, will increase the odds of your photo being accepted for the Yahoo Weather app. The guidelines:
1. Do not have people as the focal point. The image may include people so long as they are not recognizable. In other words, any person in the image must not be the focal point but may be a part of the background.
2. The photo must reflect the state of the weather in the sky, in day or night for any of the following weather conditions: Clear, Cloudy, Rain, Storm, Fog, Snow.
3. Minimum resolution as follows:
Horizontal (landscape orientation): Minimum of 1024 px width x 554 px height
Square: Minimum of 1024 px width x 1024 px height
Vertical (portrait orientation): Minimum of 680 px width x 1024
Images larger than these sizes appear best on our app.4. No borders, signatures, watermarks, logos, overlaid text or camera time stamps. Photographer attribution will be provided automatically on the image by the Yahoo Weather app.
5. Images need to be geotagged for city and country. Landmarks are not supported. Be as specific as possible.
Using the Flickr app, snap or select your photo, and from the Details screen, tap the Add a Venue button to geotag it. Next, tap the Advanced button and then tap the Groups button. The Project Weather group you just joined will be listed; tap it and you'll see a check mark gets added to its right. Tap the Done button and then tap the Upload button and wait to see if your photo shows up in the Yahoo Weather app.