Upper Midwest Aviation Weather - Central reference for aviation weather resources, focusing on current and forecast conditions in the upper midwest region of the US, including Minnesota, Wisconsin, South Dakota, North Dakota, and Iowa.
Northwest Airlines Meteorology - Providing weather forecasting products for the aviation industry, including specialized turbulence and thunderstorm forecasts.
Landings: Aviation Weather - Large database of aviation specific weather links.
Base Ops - Aviation Weather for Flight Preparation with TAF Metar Sigmet Radar and Sat-pictures.
Data Transformation Corp DUAT - FAA's Direct User Access Terminal service provides free aviation weather and flight planning for certified pilots in the US.
Ace's Pilot Shop Weather Data - Aviation weather and flight planning, including forecasts, observations, weather maps, DUATS briefings, icing, and turbulence.
Winds and Temperatures Aloft - By selecting one of over 160 continental cities in the U.S.A. or one of 30 cities in Alaska, you can obtain wind direction, speed, and temperature forecasts.
Aviation Weather Center - The National Weather Service's aviation weather site with official forecast products as well as experimental products.
Enflight - Obtain plain-language weather briefings using exclusive WXpert translation. View up-to-date weather graphics. Helps prepare and file flight plans. Available both on the Web and on mobile PDAs (Palm i705, etc.)
Pilot's Guide to Aviation Weather Services - An online brochure to help pilots use the "National Aviation Weather System."
SA Weather Service - Aviation - Provides weather services for the aviation industry in Southern Africa. Includes metars, sigmet charts and forecasts.
WSI - Provides pre-flight and in-flight weather information. Aviation weather also available online through WSI Pilotbrief.
Flying in Europe - Weather information for flying in Europe, including all airport notams, calculations, country information, airport webcams, FBO database, and all aviation abbreviations.
Pilot Weather Briefing - Free weather information for pilots, including surface conditions, upper level winds, turbulence, icing, thunderstorms, TAFs and Metars, radar and satellite images.
Turbulence Forecast - Turbulence forecast maps for around the world.
BalloonCast - Customized weather for balloon pilots. METARs, TAFs, winds aloft, sunrise/set for multiple stations compared side by side, all codes translated to English and times converted to local.
Aviation Weather - Satellite maps displaying live pilot reports, current and forecasted weather (PIREPs, METARs, TAFs) with optional radar overlays.