• Weather Underground
  
  This is probably the best radar, with storm track, the ability to zoom in and a variety of other features. For additional radar types on the Weather Underground site, click the box above the radar image once you have selected a radar site. Also has Canadian radar data.
• Weather Underground's WunderMap - Interactive Radar
  Weather Underground's WunderMap is one of the best weather tools available. It allows you to view radar data combined with weather stations, satellite data and a wide variety of other features. You can choose what you want on the map. You can zoom in as close as your house or as far away as you want. Also has Canadian radar data.
• National Weather Service Radar
  This is another good site for radar. There are also regional radar views.
• Intellicast Radar
  This site is also good to use to view an entire regions worth of radar data. If you want to see a large part of the storm in one radar as it makes landfall, this is a great radar to do it with. The radar loops on this site are also longer which is a nice feature to use.
• Weather.com - Interactive Radar
  This site also has layers such as clouds, temperatures and winds. Also has Canadian radar data.

North & South America

• Aruba (Netherlands)
  As of posting this, they link to a radar site in Venezuela. Radar is also available from Curaçao (Netherlands).
• Bahamas
  As of posting this, their site has not been available since 2016. Their radar had not been available for many years before that.
• Barbados
  150km, 250km and 400km range loops are available.
  
  Barbados also has an excellent Caribbean Radar Composites page. Be sure to check the imagery there if the Barbados radar has any issues:
  
  Entire Caribbean | Eastern Caribbean and part of South America | Eastern Caribbean | Northwest Caribbean
• Belize
  50km, 250km and 400km range loops are available.
• Bermuda (U.K.)
  100km, 250km and approximately 430km range loops are available. Additional imagery is also available, but for the additional options, including the approximately 430km range loop, you will need Java.
• Brazil
  There are two main sites that contain most of the radar images.
  
  Satellite and Environmental Systems Division - 240km to 250km range loops are available.
  
  Radar site from Brazil's military - 400km range loops are available.
  
  You can also view some additional radars for other parts of Brazil below:
  
  Teixeira Soares and Cascavel, Paraná Mosaic - 475km ranges
  Quixeramobim, Ceará - 400km
• Canada
  250km range loops are available.
• Cayman Islands (U.K.)
  50km, 250km and 400km range loops are available.
• Colombia
  A radar mosaic is available above. Approximately 300km range loops are available for the island of San Andrés east of Nicaragua, Corozal near the northwestern coast of Colombia and for near the capital Bogotá. As of posting this, individual links to radar sites from Pasto and Medellin were not available, though Medellin radar does seem to be included in the mosaic.
• Cuba (Mirror)
  Approximately 450km range loops are available.
• Curaçao (Netherlands)
  150km and 450km range loops are available.
  
  Curaçao also has an excellent Caribbean Radar Composite page.
• Dominican Republic (radar not yet available again publicly as of updating this page for this country)
  As of June 23rd, 2018, a 300km range loop has sometimes appeared on their meteorological service's Twitter feed. (link to tweet where it first appeared) The director of their meteorological service began posting images on her Twitter feed on June 20th, 2018. In a reply to that first tweet containing imagery, she said that "When the trial period ends, the next step will be to make it available to the general public." (translated by Google) In a June 11th, 2018 tweet she said "Technicians of @Onamet receiving training in the handling of the new software and hardware of the Punta Cana weather radar." (translated) In the tweet she posted pictures of the technicians receiving training. The radar is located at about 18.522197N 68.392656W.
• El Salvador
  Various 120km radar loops are available.
• Guadeloupe (France)
  A closeup image centered on Guadeloupe is also available on this page.
• Guantanamo Bay
  Only the 124nm short range loop is available. It is sometimes out of date.
• Guyana
  When available, 150km, 250km and 400km range loops are available. As of posting this, imagery was not available.
• Honduras
  250km and 500km range loops are available. As of updating this page in early June of 2018, the radar page on their site has been compromised. The page will try to redirect you to a malicious site. If you still want to visit, the link exists as a comment in the HTML of this page.
• Jamaica
  240km and 480km range loops are available at times. Make sure the time is current if imagery is available as this site often has imagery that is outdated or unavailable. The link to the page also changes at times.
• Martinique (France)
  400km range loops are available from Martinique and Guadeloupe.
  
  Antilles - Radar view of most of the Lesser Antilles in the eastern Caribbean Sea.
  
  Caribbean Radar Mosaic - Lesser Antilles as well as other radar sites, when available, including the Cayman Islands, Trinidad and Tobago, Guyana and French Guiana.
• Mexico
  300km range loops are available for most locations, with some locations with a lower range, such as 240km. The availability of some of their radar sites sometimes changes. Some of the sites below may be available even when they are sometimes not included on Mexico's main radar page.
  
  For near Mexico City, in the interior of Mexico, a 250km range single radar image is available here.
  
  For the state of Guanajuato, in the interior of Mexico, a radar loop is available here from the Secretaría de Seguridad Pública del Estado de Guanajuato, Protección Civil. (Secretary of Public Security of the State of Guanajuato, Civil Protection) The city of Guanajuato is about 280km northwest of Mexico City.
  
  For the states of Guanajuato and Querétaro, in the interior of Mexico, a 240km range loop is available here from the Comisión Estatal de Aguas de Querétaro. (State Water Commission of Querétaro)
• Nicaragua
  450km range loop is available.
• Panama
  Panama Canal - An approximately 120km range loop is available.
  
  Panama Meteorological Service - As of posting this, they display the Panama Canal radar site.
• Puerto Rico (U.S.)
  On September 20th, 2017, Hurricane Maria seriously damaged the NEXRAD radar site. On June 15th, 2018, the new radar began releasing data during a testing phase. As of updating this page for Puerto Rico, some of the NOAA links below redirect to the temporary radar page that existed while the radar was not working.
  
  124nm and 248nm range loops are available for the NEXRAD radar site in Cayey:
  
  Weather Underground: Short Range | Long Range
  NOAA: Short Range (redirects) | Long Range (redirects) | Single Image Long Range Loop (working)
  
  48nm and 225nm range loops are available for the Terminal Doppler Weather Radar (TDWR) site in San Juan:
  
  48nm Range (0.20° Elevation) | 225nm Range (0.60° Elevation)
• Trinidad and Tobago
  150km, 250km and 400km range loops are available. The first two ranges have other radar products available too.
• Venezuela
  400km range loops are available. Some radar sites cover Aruba, Bonaire and Curaçao. Sometimes some radar sites are unavailable.

Other Areas

• Belgium
  240km to 300km range loops are available.
• Canary Islands (Spain)
  The maximum radar range might be 300km, but a 240km range loop is available. Radar can be viewed at Spain's meteorological service.
• Denmark
  240km range loops are available.
• Estonia
  250km range loops are available.
  
  Composite images of Nordic countries: Norway | Sweden | Finland
• Finland
  250km range loops are available.
  
  Composite images of Nordic countries: Norway | Sweden | Finland
• France
  256km range loops are available.
• Germany
  180km range loops are available.
• Iceland
  The maximum radar range is 480km, though a lesser range composite loop of the two radars is available, likely out to up to 240km.
• Ireland
  250km range loops are available. Radar data can also be viewed at the United Kingdom's Met Office.
• Latvia
  250km range loop is available. Click the image on the page to view a loop.
• Lithuania
  250km range loops are available.
• Netherlands
  The full radar range of the two radars is 320km, though a lesser range composite loop is available.
• Norway
  240km range loops are available.
  
  Composite images of Nordic countries: Norway | Sweden | Finland
• Poland
  250km range loops are available.
• Portugal
  300km range loops are available.
• Spain
  240km range loops are available.
• Sweden
  240km range loops are available.
  
  Composite images of Nordic countries: Norway | Sweden | Finland
• United Kingdom
  255km range loops are available.